■: '
II
SMt^A^ 1 .sdce-MSYaid
tribute to his genius — it will be well to proceed with the presen-
tation of the meaning of " interchangeability " and the develop-
ment, perfecting, and installation of the system for which it
stands.
INTEECHANGEABILITY.
Interchangeability mechanically means to produce parts in
duplication or repetition, or the production of a part or piece
which will fit into the place provided for any other similar piece.
As a rough sample of interchangeability we might take, for in-
stance, the work of the brick-layer, the tile-setter, or the mosaic-
worker, who when building a wall or blocking a panel take any
brick, tile, or cube that lies nearest to their work, knowing that
it will take up the same amount of space and fit into place the
same as those laid before it. In metal, a rough sample of inter-
changeability is met with when laying a line of water-pipe, the
castings being dropped indiscriminately along the street, the con-
tractor knowing full well that one end of each will fit into the
recess of the end of the preceding one.
From the laying of bricks, tiles, and water-pipe to the mak-
ing of watches is quite a long step ; but as the modern watch,
cheap and expensive, represents the other extreme of inter-
changeability, developed to a degree almost incomprehensible to
the ordinary mind, it is a fitting illustration. In the manufac-
ture of the watch hundreds of parts go to make it up. Take the
screws — the tiny little things that one can hardly see with the
naked eye ; they are manufactured by the million, and so accu-
rately that the last one will fit perfectly into the tapped hole
provided for the first one. The gears, springs, brackets, pinions,
pivots, bearings, and shafts are all interchangeable.
INTERCHANGEABLE MANUFACTURING. 21
In referring to interchangeability it must not be inferred that
the system is only met with in the production of fine work ; on
the contrary, the fact is that the system is easier of installation
and of as frequent occurrence with rough work.
In modern manufacturing the first object sought is to produce
cheaply and therefore rapidly, and this object can only be at-
tained by producing the parts or machines of the same kind in
duplication. Some infer that these modern manufacturing
methods have been adopted on account of the scarcity of skilled
labor, when the fact is that it has been the great supply of highly
skilled labor that has made the development, perfection, and in-
stallation of the wonderful system of interchangeable manufac-
turing possible. Thus where years ago the skill and ingenuity
of the mechanic were monotonously and patiently utilized in the
hand production of a number of parts of great accuracy to a cer-
tain attainable degree of duplication, they are now directed to
the devising and constructing of one part or tool, or a set of tools,,
which will produce other parts or tools in endless repetition.
In modern machine manufacturing skill and ingenuity of an or-
der higher than were ever thought possible to attain have beeu
developed in the hands and brains of the American tool-maker.
And this skill and ingenuity are concentrated upon the devising
of means for the production of articles and parts within the
slightest possible limits of variation, and in which their complete
interchangeability will be guaranteed.
The man in whose brain the modern manufacturing system
was born was he that first took a piece of scrap-iron and drilled
two holes in it, to guide a drill in making another piece with two
holes in it the same distance apart as in the first piece. The
men who now fill our drawing-rooms and tool-rooms and who de-
vise and construct tools for the production of interchangeable
metal parts are his descendants. They have made possible the
manufacture of the breach-loading gun, the typewriter, the cheap
sewing-machine, the cash-register, the machine-made watch, the
automobile, as well as a thousand and one other mechanical arti-
cles, machines, and devices, which form an integral part of our
twentieth- century civilization.
22 TOOL-MAKING AND
INTEBCHANGEABLE MANUFACTUBING.
The development of the modern system of manufacturing
since the days of Eli Whitney has been simply wonderful, so that
at the present time all machines for which there is a constant or
a large demand are or should be manufactured and built through
this system of interchangeability. It is in the perfecting of this
system and in the designing and constructing of tools and appli-
ances for the successful production of machinery that the best
and brightest men in the mechanical field are employed. Take
the universal milling-machine, the precision-lathe, the automatic
screw-machine, and turret-lathe; all these machines are being
manufactured to-day by a system which allows of their being
constructed and shipped to any part of the world with their effi-
ciency guaranteed. Moreover, any one of their innumerable
parts can, when worn out or broken, be duplicated by sending
to the works and securing the part needed. This part can then
be fastened in place of the other without as much as touching it
with a file, when it will perform its separate and distinct move-
ments as positively and accurately as the part whose place it has
taken.
"When one realizes that, in order for these machines to do the
work expected from them, each and every part, from the most
minute screw to the largest casting, must be finished to a degree
of accuracy almost inconceivable to the lay mind, the fact that
all the parts will interchange with those on another machine be-
comes more surprising. Now if all the parts of a modern ma-
chine tool must be finished so accurately, to what degree must
the tools and appliances used to produce them be finished? And
what of the men who have the skill and mental capacity neces-
sary for the successful designing and constructing of such tools !
If it is considered that twenty years ago precisiommachine
tools of the present efficiency could not have been constructed,
not even if the best mechanics available were employed on the
work, the fact that they, as well as numberless others, are now,
and have been, built by thousands, becomes more astonishing.
The reason why such machinery could not have been per-
fected and constructed to accomplish the results now attained by
INTERCHANGEABLE MANUFACTURING. 23
them was that there were not at that time tools and machines of
the necessary precision and accuracy to build them, and it was
only by inventing and developing the use of such tools that the
manufacture of such intricate pieces of mechanism as the modern
universal miller, precision-lathe, etc. , was made possible. Nat-
urally, in order to develop and construct these tools, the minds
and hands of the mechanics had to be developed, until to-day the
amount of brains, skill, and mental capacity involved in the de-
signing and constructing of special machinery, dies, tools, and
fixtures for the manufacturing of metal parts, articles, appli-
ances, and machinery, is equal to — if not greater than — that
called into use in any of the other arts and professions.
This may seem a rather strong assertion to make, but it is
made with the full knowledge of what it means. It may not be
apparent to all, but to the man who has had the advantage of
practical observation and experience in the manufacturing of
machinery it is both right and just. It is well that the fact is
becoming universally recognized that men of the highest and
rarest attainments are engaged in the devising and developing of
means for the rapid and economic production of machinery.
MODERN MANUFACTURING OF INTRICATE
MACHINERY.
As a practical illustration of what the modern system of
manufacturing consists and how it is installed and carried on, I
will take up the various arts called into use and necessary to the
successful constructing and placing on the market of a machine
for which there is a large demand.
After the developing and experimenting has reached a suc-
cessful conclusion in a perfect working model, the first thing
necessary is the designing and making of full sets of wood and
metal patterns, to be used for casting the various parts which are
to be cast. The man that does this must call into play a vast
amount of ability and knowledge in order to accomplish this part
of the work. He must allow of all parts being sufficiently
strong, so that the castings resulting will withstand all strain to
which they may be subjected when in use, and he must provide
for giving them, as far as possible, a symmetrical and artistic
24 TOOJu-MAKING AND
appearance. He must also allow for shrinkage in the metal
when cast and for a certain amount of surplus stock at all points
which are to be machined and finished.
After the pattern-maker has produced these patterns in exact
duplication of the designs, they are sent to the foundry, where
the moulder utilizes his skill and brains, and, with the patterns
as models, a heap of sand and a few crude tools to work with,
works out his moulds, from which a set of castings are produced.
This set is first machined and finished by the use of the best
means available, which calls into use all the capacity and skill of
the machinist. After all parts have been finished and assem-
bled, a finished machine is the result. Any defects in shape or
strength in the patterns have now become apparent in the fin-
ished castings and the parts. The patterns are then carefully
gone over and these defects rectified, and another set cast from
them. This set is also finished and machined, and then assem-
bled in another machine. This latter machine is found to be a
great improvement over the first, as all defects and inaccuracies
have been rectified and each and every part has been machined
as accurately as possible.
The machine now goes to the tool-designer, who is called
upon to scheme up and design complete sets of tools, dies, fixt-
ures, and appliances for the machining of all castings in repeti-
tion and for the exact duplication of each and every other part,
from the largest shaft and gear to the smallest pin and screw.
To be capable of accomplishing all this the designer must be —
first of all — a practical man, familiar with all mechanical princi-
ples necessary to the successful construction of the tools, as well
as be possessed of a theoretical knowledge of the properties of
all metals. He must design the tools to be both positive and
accurate, as well as strong and durable. He must also allow of
their being constructed as simple as possible, consistent with ac-
curate production and rapid handling when in operation. He
must, lastly, he certain he is right in all measurements down to
the smallest fraction of an inch. In fact, he must construct a
perfect set of tools for the exact duplication of all the parts of
the machine on paper. The designer must also provide for the
tools being so constructed as to allow of being handled and oper-
INTERCHANGEABLE MANUFACTURING. 25
ated to their fullest capacity by men of the average skill aud
intelligence, with rapidity and without the possibility of error.
By the time the designer has accomplished all this and gone over
and verified all his designs, until he is sure of their accuracy and
of their coinciding perfectly where necessary, he has finished his
part of the work.
The tool designs and the machine now go to the tool-maker ;
he has the last, but not least, proposition to tackle. Where the
pattern-maker had to produce his designs in wood, the draughts-
man his on paper, and the moulder his in sand, the tool-maker
has to create his in steel and iron, which can neither be whittled
with a knife, nor the parts fastened together with glue, nor the
mistakes and inaccuracies rubbed out with an eraser. Neither
can the tool -maker shape his work in sand and locate the points
with a trowel. He is the man on whom the accuracy, efficiency,
and working qualities of the finished product depend. His skill,
ingenuity, and powers of creation and production are taxed to
their fullest extent indeed ; and, unless he is a man of brains,
skill, and experience, all work of the designer, pattern-maker,
and moulder will have been useless. First in the machining and
finishing of the tools and the placing of all locating points, and
then in the assembling of the parts, is his knowledge and skill
called into play. As each tool, fixture, or device for the produc-
tion of some special and distinct part is finished, it must be tried
and proved ; and the piece machined in it must fit exactly in its
proper position and coincide perfectly with all other points nec-
essary in the other parts, so that the performance of its separate
and distinct motion will be guaranteed. And thus on to the end
of the list, until the full set of tools is complete, so that a perfect
and complete machine can be constructed by their use, with the
certainty that all parts machined in them will be found to inter-
change perfectly, so that they may be selected haphazard in the
assembling of a new machine or in the repairing of an old one.
When all the foregoing has been accomplished, the preliminary
work necessary to the successful manufacture and perfect opera-
ting of the machines in any number desired, with the certainty
that each and every one will be an exact duplicate of the others,
from the smallest pin or screw to the largest casting, is an accom-
26 TOOL-MAKING AND
plished fact. We may now go ahead and manufacture by means
of the interchangeable system, which allows of the construction
of machinery at the minimum of cost and to the maximum of
production ; and, what is more, allows of constructing machines
in exact duplication of each other, which could not be accom-
plished by any other means.
THE AMERICAN TOOL-MAKEE— THE MOST SKILLED
MECHANIC YE THE WOELD.
When all the skill, capacity, and brains utilized iu the accom-
plishment of the mechanical results outlined in the foregoing are
considered, is it irrelevant to make the assertion that the genius
and intelligence utilized in the inventing, developing, perfecting,
and manufacture of machinery are second to none and above
most ? We think not ; and if any one who doubts the truth of it
will stroll through a modern machine-shop, of the kind necessary
to the production of intricate, labor-saving machinery, and notice
the various operations through which the parts used in the con-
struction of such machinery go, and the special tools, fixtures,
appliances, arrangements, devices, and machinery used for their
production, we think he will change his mind and will be grate-
ful that America and Americans can boast of men who are capa-
ble of such things ; for it is to such as they, more than all others,
that we owe our commercial and industrial supremacy of to-day.
The great changes in the last century, which have contributed to
the uplifting and betterment of the human race, are marked by
the achievements of men whose whole lives and energies have
been devoted to the perfection and production of things mechan-
ical. This genius of invention which has conceived, developed,
and made possible the manufacture of labor-saving machinery,
has multiplied and improved the necessaries as well as the luxu-
ries of life.
We are known and acknowledged to-day as the greatest world
power. What has made us so ? It is to those who have devel-
oped and perfected our modern manufacturing industries that we
owe the most. It is because we can view with equanimity the
strivings of other nations to outdo us ; because we can go out
into the markets of the world and meet and overcome their com-
INTERCHANGEABLE MANUFACTURING. 27
petition, that we are what we are. And how has this come
about 1 ? Simply through the great inventive ability and ingenu-
ity of American engineers and mechanics. Thus has the pro-
duction of all articles and necessaries of commerce been cheap-
ened and multiplied. Go into the drawing, construction, or tool
department of any of the large machine establishments and note
the men employed therein. They will be found to bear favorable
comparison with those engaged in any of the other arts or profes-
sions. What is more, these men do not stand still, but keep
increasing their knowledge, and thus step higher and higher to
positions which their ambitious and capacities entitle them.
From the ranks of such men come the best of our inventors of
machinery, our superintendents and managers.
Before closing this introductory chapter, I will say the indus-
trial supremacy of the United States in the twentieth century has
come about through the developing and perfecting of the modern
system of interchangeable manufacturing, and will ever stand as
a monument to the skill and ingenuity of the American me-
chanic.
CHAPTER II.
Machine Tools, Designing, Tool-making, and Tool-
Rooms.
MACHINE TOOLS.
It has been well said that the foundation of the industrial
structure of to-day rests on machine tools ; and with this state-
ment, I believe, all who are familiar with the mechanical devel-
opment of the last decade and have given any thought to indus-
trial betterment will agree. It is a fact, that all must now
concede, that without these machine tools, these wonderful fac-
tors in modern civilization, we would be reduced to the state of
primeval man and be forced to do by hard physical labor that
which thousands of automatons now accomplish for us. It is with
machine tools that all other machinery is produced ; the standard
tools of the universal shop, the lathes, drills, planers, shapers,
millers, boring-mills, and the numerous minor members of the
great family, are all called upon to contribute their share to fur-
ther economic modern manufacturing.
Now, in view of the afore-mentioned facts, it must be obvi-
ous to all that the nation which aims to lead in industrial mat-
ters must be the one that possesses the most efficient and best de-
veloped machine tools, as the possession of such is a criterion of
the mechanical skill and ingenuity of the country's mechanics.
Hence where the best machine tools are found there will also be
found the best knowledge of how to operate them to the best ad-
vantage. Thus we arrive at the conclusion that if good tools are
to be made, a comprehensive and broad knowledge of how tools
should be used and the amount of work they should do is abso-
lutely essential. Of those who are possessed of this knowledge, it
may be said that they are indeed ornaments to their profession,
as they stand equipped to produce means which will lighten the
load bequeathed by Mother Nature to both man and beast —
means for doing the world's work economically and efficiently.
28
INTERCHANGEABLE MANUFACTURING. 29
THE DESIGNEE.
When considering machine tools we are at once confronted by
the fact that the efficiency of any machine, device, arrangement,
or 1 tool used in manufacturing is determined solely by the quality
and quantity of its output. To some extent this is modified by
the skill of the workman using the machine or tool. However,
machines and tools should be designed and constructed so that
the factor of skill in handling will be ineffective except in con-
tributing to produce a better quality or a greater quantity of
work than is demanded in the specifications.
Now in order for the designer to be capable of designing a
machine or a tool which will meet modern requirements, he must
first be thoroughly practical and familiar with the details of the
various lines of manufacture in which his creation is to be em-
ployed. A theoretical knowledge of the properties of all materi-
als, under all conditions, must also be possessed by the man who
wishes to accomplish things in tool design, before he can hope to
solve the innumerable problems which will confront him. When
the vast field to be covered is considered, it is plain to all that
the task that is set is no ordinary one and that his mental equip-
ment must be very complete in order for him to succeed. It is
well that the comparatively limited number of methods employed
in the working of metals contribute somewhat to the lightening
of his load. These methods may be enumerated as follows:
forging, rolling, pressing, turning, drilling, tapping, planing,
milling, grinding, punching, shearing, and sawing. This list
comprises the most important methods ; the rest are minor and
may be virtually classified under some one in the above-enumer-
ated list.
THE GEEAT PRINCIPLE OF REPRODUCTION.
The designing and constructing of fixtures and special tools
to be used in machine tools for modern manufacturing represent
the highest application of the great principle of reproduction.
It is this subject that we are about to take up, and it compre-
hends not only the tools known as jigs and fixtures, but all spe-
cial tools of various types which are in general use to-day for the
30 TOOL-MAKING AND
cheap and accurate production of parts in duplication and repe-
tition, whether of metal or other material. The inception of the
grand principle may be traced back almost to the beginning of
time.
Perhaps the earliest application of the principle of reproduc-
tion was in the moulding of plastic materials which were after-
wards baked. From the days of the first use of moulds to the
application of the principle in the art of printing was a long
step, yet it was in that art that it next found use in printing
from hand engravings and afterwards from removable type. Fol-
lowing this, the principle was applied in the making of repro-
ductions of paintings and lithographs, in the coining and stamp-
ing of metals, and then in the casting of metals and numerous
other materials. In fact, I might go on for pages and trace the
application of the principle of reproduction down to to-day, and
at length stop at a set of tools for the repetition production of a
modern universal milling-machine or a precision-lathe.
The most advanced application of the principle of reproduc-
tion in which we are interested is to be found in the use of tem-
plets, gauges, jigs, fixtures, and cradles, as those tools are chiefly
used in working and cutting parts of metal, to a limited degree
of variation, which have been previously roughly formed by the
(processes of rolling, drawing, forging, or casting.
FUNCTIONS OF JIGS AND FIXTUEES.
v in\ jigs and fixtures their functions are often combined with
those of machines in which they are used, such as a machine of
special design fitted for operating on parts of the same size and
shape, the work being located and the tools operated by devices
self contained in the machine. This we find in a multiple spin-
dle drill, which has been specially equipped for drilling all holes
in a part of a machine or in a large plate, the drill-spindle cases
being rigidly fixed in position in a certain relation to each other.
In a machine of this type the position of the drill spindles repre-
sent the jig, as it is only necessary to place the work on the table
and the holes may be drilled in the same position as those in the
preceding piece.
INTERCHANGEABLE MANXJFA CTURING.
31
TEMPLETS.
Templets are tools made of flat pieces of metal, usually
sheet metal, which, are used to -lay upon surfaces and are lo-
cated by the eye, fingers, or fixed flanges or pins, etc. , so that
certain edges of the templet, out-
side or inside, may be used as a
guide for scribing outlines of them
on the surfaces of the work — the
outlines to serve as guides for drill-
ing holes, cutting grooves below
the general surface, or for forming
the outer or inner edges of the part
to the external or internal outlines
of the templet. Thus a tool of this kind reproduces marked lines
with accuracy to a degree dependable upon the care taken by the
user. The working to those lines afterwards, however, is subject to
variable error, as much depends upon the skill of the workman.
As an illustration, let us say that we make a templet of con-
siderable thickness and secure it firmly to the work, so as to allow
of using the locating edges for actual guides for the cutting tools
Fig. 1.
1 \
/ J
) r^ i **> .
o C
F — ' . (S)
\ 1
Fig. 2.
Fig. 3.
— take Figs. 1 and 2, for instance. By doing this we get the
simplest form of flat jig. When the outside edges of such a
templet are used to locate finished edges in the work, the tool
bceomes either a filing, milling, shaping, or planing jig, as the
case may be. The most usual use of a flat jig, however, is to lo-
cate cylindrical holes of various sizes and kinds to be drilled
with drills or other similar tools, or to locate grooves, angles, or
keyways in parts in certain relative positions with other finishing
points. Fig. 3 illustrates a die templet.
32
TOOL-MAKING AND
GAUGES.
In gauges, their general function is to verify standard meas-
urements between points and locations. While the use of such
tools is well enough known to make a detailed description of them
superfluous, a few remarks are essential. Iu accurate work
" limit " (Fig. 4) gauges are frequently -
used. One gauge represents the maxi-
mum of allowable inaccuracy and the
other the maximum of accuracy re-
quired — the work coming within these
allowable limits.. Thus we see that
the purpose of gauges is not so much to locate the points of the
various finished surfaces in a piece of work, as to inspect them
after they are so located.
Fig. 4.
FLAT JIGS.
In regard to flat jigs it may be said that the simplest form
consists usually of a flat plate of iron, through which certain
holes have been accurately located and carefully drilled; the up-
per and lower surfaces of the plate having first, of course, been
=1
oooooooooooooooo
DOOOOOOOOOOOOOOof]
\=J
Fig. 5.
Fig. 6.
machined true. Thus if a flat jig is in the form of a square, or
of rectangular shape, and of considerable thickness, as shown in
Fig. 5, or, in other words, of the same shape and size as the
parts which are to be drilled, it may be clamped in position on a
drill-press table and a pair of parallels used to set against two
of its edges, the parallels being set at right angles to each other
and clamped when the drill has been set to enter one of the holes
to the depth required, or all the way through, whichever may be
the case. After this has been done the model or flat jig may be
INTERCHANGEABLE MANUFACTURING. 33
removed and the parts drilled in exact duplication of it by setting
them against the parallels and clamping them and then drilling.
Then again the fiat jig may be made to fit the top of the work
and the holes drilled by guiding the drill through those in the jig.
A type of fiat jig most generally used is shown in Fig. 7.
They are usually equipped with downward projecting lugs or
pins, which are used to locate the jig on the work, thus obviating
the necessity of depending on the hand or fingers of the operator
for the locating. Very often devices, such as screws, clamps, or
other fasteners, are contained in the jig (Fig. 8), being located
Fig. 7. Fig. 8.
upon one or more sides of the jig, the same serving to pull the
jig in one or two directions against the work. Where the work
varies in size or shape, such as in castings, the clamping is usu-
ally central and made to operate in all directions, so as to com-
pensate for the degree of variation in the castings.
s
BOX-JIGS.
In the further development of the reproducing principle, we
come to the box-jig. This type of jig stands upon its own bottom
when in use, the work being dropped into it and located by suit-
able means against stops and down on bosses on the sides of the
jig and on the inner surface of its bottom. A jig of this kind is
usually equipped with a lid in which the bushings for guiding
the drills are located. Very often the work is located and fast-
ened within such jigs by merely dropping the lid down and fast-
ening it. When all holes to be drilled in a box-jig are to be par-
allel to each other, the jig always stands upon its bottom while
in use ; but when holes are to be drilled at right angles, from the
top and sides or from any of the six sides of the jig, it is neces-
sary that all opposite sides from which drilling is to be done
A. T.— 3
34 TOOL-MAKING AND
should be provided with surfaces for resting the jig on the table.
These resting surfaces or "bottoms" may be at any desired angle
to each other, may be cast with the jig body and machined and
squared, or be of steel and screwed or forced in.
Box- jigs of the most common types are frequently used for
drilling all holes in frames of small machines, standards, or other
similar parts. The work is put into the jig and located by cer-
tain surfaces which are most favorable for producing uniformity.
After the work is located the jig is placed on the table of a gang
drill and all holes finished as desired ; drilling, counter-boring,
boring, or reaming, as may be desired, each spindle of the drill
being equipped with the proper tools to accomplish the opera-
tion required. Thus by the use of such jigs unskilled labor may
be employed for drilling any number of accurately spaced holes
in thousands of pieces, with the certainty that interchangeability
will be assured. As the jig may be constructed so as to be easy
to manipulate while sliding it from one spindle to another or
turning it on its different sides, the physical exertion required of
the operator is not great ; therefore the work is accomplished
accurately with ease mentally and physically.
Again, we will often find the box-jig in simpler form, the
general shape being fiat with a number of lugs or legs projecting
downward. With a jig of this sort the' lower surface of the lugs
serve as legs, the work being clamped up against the lower sur-
face of the jig body. Then, again, there is still another type,
which might properly be called a "skeleton" jig, from the fact
that it is merely a light skeleton frame in form. It is for very
heavy work that these skeleton jigs are used, weight being a con-
siderable factor, and in order for the operator to be able to han-
dle the combined jig and work without undue exertion the jig
must be made as light as possible.
WOEK THAT SHOULD NOT BE JIGGED— JIGS FOB
HEAVY WOEK.
While most machine work can be "jigged" to advantage,
there is some that it would be obviously impracticable to handle
in this way; such as machine bases of large size, lathe beds,
large press frames, etc. On the contrary, it is always well to
INTERCHANGEABLE MANUFACTURING. 35
continue doing all necessary work on such parts, such as turning,
planing, and milling, by the ordinary methods ; using templets
and gauges for locating the finished surfaces, and then afterwards
using small local jigs or templets for locating necessary holes
from some of the already finished surfaces. When jigs are used
for such work they should be made for locating only one hole or
for locating two or a number of them which are to be placed
close together. When such jigs are made small enough, they
may be handled with ease and located in succession on various
parts of the work.
"While the saving of weight is very important in making large
jigs in order to allow of their easy handling, it must not be car-
ried too far. It is absolutely necessary in jigs for heavy work
that lightness be combined with stiffness, and this can only be
brought about through careful designing. Very often large jigs
have been carefully made which, wheu fastened to the work,
would bend or twist, thus throwing the holes and locating points
out of place, the cause being inattention on the part of the de-
signer to the factor of stiffness.
For the frames of large jigs it will usually be found best to
use cast iron, as with this metal the working parts will maintain
their position without warping or bending; in fact, they will
remain positive until a sufficient strain has been brought to bear
on them to crack them. When bodies of such jigs are made of
steel castings, forgings, or brass, they often become inaccurate,
and these defects are not usually discovered until a large quantity
of valuable work has been spoiled by their use.
CHEAP JIGS.
For small quantities of work cheap jigs are sometimes used.
They are made by simply drilling the working holes through the
body of the cast iron or steel plate of which they are made. Of
course, jigs of this construction are not very durable, as the
drills wear the holes and the alignment is not maintained.
Then, again, such jigs are made by fastening a hardened steel
plate in which the proper working holes have been drilled to the
frame of the jig. However, the use of hardened steel plates for
the purpose designed is somewhat interdicted by the warping of
36
TOOL-MAKING AND
the steel in hardening, thus destroying the alignment and displac-
ing the holes in their relation to each other.
ACCURATE JIGS.
When large quantities of accurate work are to be done in
jigs, the tools, of course, should be carefully made. In such jigs
drill guiding holes should always be bushed with hardened,
pig. 9.
lapped, and ground steel bushings, made to standard external
diameters, so that they may be easily replaced when the inside
has been worn by the revolving of the drills while working.
Such bushings are usually forced tightly into reamed holes in the
jig bodies. For producing accurate work in small quantities
interchangeable bushings are used, a full set of them being kept
on hand. These bushings may be used in any of the large jigs in
the shop indiscriminately.
TOOL-BOOMS AXD THEIR EQUIPMENT.
Katurally, in a chapter devoted to the value of tools and the
evolution and development of tool -making, one expects to find
INTERCHANGEABLE MANUFA CTTJRING.
37
something on tool-rooms ; at all events, a few remarks on the
subject will be timely.
Tool -rooms are of two classes — those in which tools and fixt-
ures are made and those in which they are kept. In those of
the first class the most important item is the lathe. An approved
type of a modern tool-maker's lathe is shown in Figs. 9 and 10,
Fig. 10.
the general features of which are apparent. It is a ten-inch,
tool-maker's lathe, and its design and construction represent the
attainment of perfect and complete convenience. It is one of the
most complete precision-lathes ever produced for the tool-maker
or model-maker. Now, of all machine tools, for either tool-mak-
ing or manufacturing, the lathe is king. If a machine-shop or a
tool-room is to have only one tool in it, it is obvious to all that
the tool should be a lathe, and it should be a good lathe. With
a good lathe and a skilled mechanic to operate it and bring out
all its capabilities, almost anything in the line of tool-making
and machine construction may be accomplished. As to-day lathes
38 TOOL-MAKING AND
are being built in the most astonishing variety of capacities, from
the delicate precision-lathe to the ponderous three-hundred tons
gun-lathe, no difficulties should be experienced in procuring one
for any special line of tool-making or manufacturing.
After the lathe, next in importance comes the drill-press, the
selection of which depends upon the class of work to be done.
Usually there should be two — a small sensitive drill and a large
column machine. Next we have the universal milling-machine,
with its boundless possibilities. In order of importance the
shaper and planer come next, and in their choice the nature of
the work to be done is also the chief factor to be considered.
Vises and small tools, of course, follow; then the speed-lathe,
for hand-tooling, polishing, and lapping. Lastly, the modern
tool-room is not complete without a tool-grinder. All of these
machines are sufficiently well known and a detailed description
of any would only take up valuable space.
In regard to a tool-room of the second class, it must be obvi-
ous to all that its chief requisites are that it shall form a conven-
ient place where tools and appliances may be systematically
and handily distributed. In a small establishment only one tool-
room is necessary, but in any extensive establishment, where
there are several buildings and several floors in each building, it
is necessary that there shall be a number of tool-rooms in order
that there shall be convenience in the distribution of the tools.
In order that the reader may understand what a tool-room
should be like, it is essential that a short description of a model
one should be presented. I know of no better way of doing this
than by describing those in the shops of Brown & Skarpe, Provi-
dence, E. I., U. S. A. In their shops the different tool-rooms
are much alike, the largest one being on the second floor of the
main building, where all lathe tools are ground on a Seller's
grinder before being given out, and other work of like character
done. Like all shops in which large numbers and varieties of
tools are in use, the check system is in use. Ten checks are giv-
en each workman, one of which is placed opposite the place re-
served for any tool that he has out. One noticeable and excel-
lent feature of these tool-rooms is the good supply of parallels in
each. To save checks, when a workman requires several paral-
INTERCHANGEABLE MANUFA CTUBING.
39
lels the system shown in Fig. 11 is in use. The parallels are placed
in pigeon-holes, those of one size in one row, the next larger in a
row below, and so on. At the right is a board, on the side of
which is marked the size of the parallels in each row, and at the
top of which are the numbers 1 to 6, to indicate the number of
parallels in use. Checks in the positions shown would indicate that
a workman had out four 1^-inch parallels and three 2f-inch ones.
In a great many shops it is common to keep the tool -rooms
supplied with sets of taps and tap-drills together in two blocks,
13 3 4 5 6
iyJL
w/s" -0, .
ate.
rn
i — i
i i
i — i
i — i
i i
1 1
rn
i i
i i
i i
i i
1 I
I I
i i
i i
i i
i i
rn
'rn
rn
rn
i i
i i
1
1
3x3"
m?— O
m
rn
rn
rn
rn
m
FIG. 11.
only one check being necessary to secure the whole. In the
Brown & Sharpe tool-rooms the tap blocks are more completely
equipped than usual. Each set or block consists of a full set of
drill, tap-drill, starting, sizing, and bottom -tap, two counter- bores
for holes where countersunk head-screws are used, one counter-
bore having a tip the size of a standard hole and the other to fit
a tap-drill hole ; each block also contains a test plug, giving the
size of a standard head for screws of that size and a tap-wrench.
In regard to keeping track of workmen's supplies, there is a
novel system in use. It consists of a six-sided case, one in each
tool-room, on the sides of which hang an extra size of ten checks
for each man. The top of the case is divided into several com-
partments, marked, respectively, "Oil," "Waste," "Towels,"
"Emery Cloth," etc., and when a man wants a ball of waste one
of his checks is dropped into the receptacle bearing this name.
Thus after a certain time has elapsed the checks may be removed,
counted, and a record taken of the amount of supplies which each
man has used. The checks are then put back on their pins.
CHAPTER III.
Fundamental Principles, Proeessses and Practical
Points for Jig Design and Construction.
Before taking up the various types of jigs and fixtures used
for the production of repetition parts by drilling and milling,
and illustrating them and describing their construction and use
in detail, I have thought best to devote a chapter to a presenta-
tion of the fundamental principles, various processes, and prac-
tical points which are required to be understood in order to suc-
cessfully design and construct drilling jigs and fixtures or
similar special tools used for the machining and duplication of
machine parts. If the rules laid down are followed, much un-
necessary labor and expense will be avoided and the best of
results attained. The descriptions are given from an entirely
practical point of view, the theoretical not being touched upon
and anything purely speculative being omitted.
FACTOKS INVOLVED.
In the first place, let it be understood that there is no one
other branch of the machine business that requires more thought,
wider knowledge, and broader experience of shop conditions than
the designing of jigs and fixtures, and in order for one to be
competent to do this work successfully he must xDossess this essen-
tial knowledge of shop conditions. To those who are not so
equipped a close study of the chief factors and the fundamental
principles involved will be of untold value.
In jig and fixture work there are six highly important factors
to be considered: 1. The course the work is to follow during
manufacture. 2. The locating and securing of the work in the
fixtures. 3. Keeping of the locating points for the work free
from chips and dirt. 4. Self-contained tools. 5. The class of
help that will use the tools. 6. Convenience and ease in hand-
ling the tools during their operation.
40
INTERCHANGEABLE MANUFACTURING. 41
Taking the first factor — the course of the work during manu-
facture — we will say that a part of a machine is given us to design
tools for its production in repetition. Now say that the part, in
order to complete it, will have to go through two operations,
drilling and milling. The question is which should be done
first, the drilling or the milling?
In most cases where the part is to be drilled and milled, it is
best to provide for doing the milling first ; because it is desirable
that the drilled holes and milled surfaces shall bear a certain
definite relation to each other, and because by having the holes
drilled from a milled surface greater accuracy and interchange-
ability in the parts can be obtained than if the milling were at-
tempted after the drilling of the holes. However, in order to
decide the question, a u working point or surface" must be de-
cided upon. Whether the part to be machined is a casting or
not, there is always one point which from its position — that is, in
relation to others— should be taken as a "working point," a point
to work froni and refer to in all subsequent operations required
to manufacture the particular part. The point chosen may be a
hole, a plain surface, a slot, or a lug or a boss — it matters not.
THE LOCATING AND HOLDING DEVICES.
Now having chosen the working point, it follows that this is
the point to be machined first, and that the first jig or fixture to
be made is the one for this operation. This is the secret of suc-
cessful jig-making. Also use this point for the locating of the
work in the different jigs and fixtures for subsequent operations.
Never change a working point, as the performing of one opera-
tion from one point and the next from another is not conducive
to good results.
When designing fixtures for drop-forgings, turned work,
punch-blanks, or any part that has been previously put through
a cutting, abrading, compressing, or forming operation, the con-
tour of the part is usually such that the holding of it is a simple
matter, especially if the first operation is to be a milling cut.
With castings, however, through their lack of uniformity in
many cases, fixtures of intricate and costly design are required,
thus necessitating considerable care and judgment in the devising
42 TOOL-MAKING AND
of the locating and holding means. If, instead of milling, it is
decided that the drilling should be done first, and that the holes
so produced are to be used in locating and securing the work in-
stead of using the outline, it will be found that a simpler and less
costly fixture can be used. Whichever course is decided upon,
the fixtures should be so designed as to allow of all operations of
one class being completed before commencing on another class.
Now in regard to locating and securing the work quickly, ac-
curately, and easily, these are factors of the greatest importance,
and it is difficult to discuss them properly, for the efficiency of
the finished work depends more than anything else upon them.
The various methods in universal use for locating and fasten-
ing the work to be machined in jigs and fixtures, such as bunters,
cams, set screws, spring pins, slides, flat taper pins, etc., are well
known, and I will not attempt to lay down a general rule for
their application, as this must be decided by the designer accord-
ing to the type of fixture and the nature of the work.
One of the most essential conditions necessary to the accurate
and rapid production of work in jigs and fixtures is convenience in
keeping the locating point free from dirt. This must be evident
to any one at all familiar with the use and object of such tools.
When I state that tools should be self-contained, I mean that
all devices and means utilized in the locating and securing of the
work should be component parts of the tool. When this is the
case, the operator is not obliged to use a hammer, wrench, or
any other tool in order to operate the fixture.
SIMPLE DRILLING -JIGS.
When drill-jigs of the comparatively simple types are to be
constructed for the machining of parts in which no great accu-
racy is required, the main point to be considered is the inter-
changeability required in the work after it is machined. With
this point constantly in mind, the avoiding of all unnecessary
expense and labor will not be difficult. In the construction of
simple jigs, which are to be used for the drilling of parts which
have been first finished at one or more points, or for rough cast-
ings which have not had any previous machining, the most essen-
tial points necessary to their successful construction and use are
INTERCHANGEABLE MANUFACTURING. 43
as follows : First, in making the patterns construct them so as to
leave openings in the castings at all points wherever possible,
without affecting the strength or rigidity of the castings when
finished, for the escape of the chips and dirt. Second, provide
spots with j ust surface enough to allow of their rapid surfacing.
Lastly, so design the jig as to allow of the expeditious fastening
and locating of the work and its removal when finished, as this
is one of the important factors in the operation of such tools.
CONSTBUCTING SIMPLE JIGS.
When constructing, after having done the preliminary ma-
chining of all necessary outside points, choose the most reliable
and positive points for locating the work. First, a machined
surface for the positive points for locating. When this is not
possible, those points in which the minimum of variation is to be
expected in the castings should be chosen. Then, in the fasten-
ing of the work within the jig, use means which will be the
quickest in operation consistent with all possible simplicity.
As there are any number of simple and inexpensive devices which
can be adopted to allow this, it should not be difficult.
One point which cannot be too strongly impressed on the de-
signer of simple jigs is to allow excess of metal at as few j>oints
as possible ; that is, only at the locating and squaring surfaces.
The all too prevalent habit of leaving unnecessary surfaces to be
finished is expensive and not consistent with satisfactory results.
PEOCESSES OF ACCURATE JIG-MAKING.
When drill-jigs are to be made for the drilling of work in
which the utmost accuracy is desired, the locating and finishing
of the bushing-holes is of the greatest importance, and for that
reason I give here descriptions of the most rapid and practical
methods for the accomplishment of this part of the work.
THE BUTTON METHOD FOE LOCATING DEILL
BUSHING-HOLES.
In the first place, if the jig to be made is of the box type —
which is the most generally used type — for which the body cast-
ing has been secured, after all sides and bearing surfaces have
44
TOOL-MAKING AND
been planed or milled square and true with each other, including
the feet, it should be rested on a surface plate, as shown in Fig.
12, which should be used only for work of this class. If the feet
are cast on the jig, they should be scraped until the sides of the
S
2^
SURFACE PLATE
FIG. 12.
body portion are at perfect right angles with their bottoms and
until all legs rest perfectly square on the surface plate. If the
feet are of tool steel and are screwed into the jig, they should be
hardened and lapped on a flat lapping-plate (as shown in Fig.
13), until the same results are accomplished. This preliminary
Fig. 13.
work on the jig is the basis for the successful attaining of all
other results, and unless done carefully there is no possibility of
the remainder of the work being accomplished accurately.
For the laying out or locating of the bushing-holes in jigs, and
INTEBGEANGEABLE MANTJFA GT TJBING.
45
the finishing of them, there are any number of methods in use
among tool- makers. Some of these methods allow of fair results
being attained, while others are useless, and when accurate or
satisfactory results are accomplished though their use it is pure
luck, not the method that does it. There is only one method for
locating bushing-holes in small and medium-sized jigs accurately
and expeditiously.
The following method is used by the best tool -makers on this
class of work and is known as the "button method": In shops
where jigs for accurate production are constructed, a few sets of
locating buttons should be kept in the tool-room as standard
sizes — say, five-sixteenths, one-half, and three-fourths inch in
diameter, as shown in Fig. 14. They should be of tool-steel and
finished to from one-half to one inch in length, and should have
Fastening Screw
Countersunk End
Fig. 14.
a hole through them large enough to allow about three-sixty-
fourths inch clearance for the fastening screws, after which they
should be hardened and then ground perfectly square on each
end, and on the outside to standard size, finally lapping them to
get them accurate. One end of the button should be slightly
countersunk, so that it will rest squarely on the jig when in posi-
tion. The centres for the bushing-holes in the jig should next be
located approximately correct by the dividers and then prick-
punched. They should then be drilled and tapped for the button
screws.
To locate the holes positively, first secure a button in position
by working from two sides of the jig, using a Brown & Sharpe
height-gauge, and fasten it securely by tightening the button
screw. Locate the next hole in the same manner, using the height
gauge or vernier gauge to get the buttons exactly the proper dis-
46
TOOL-MAKING AND
tance apart and. from the sides of the jig, the hole in the buttons
being sufficiently large to allow of adjusting them in any direc-
tion. After having set the buttons to the number of holes re-
quired, and having fastened them securely, as shown in Fig. 15,
Fig. 15.
the finishing of the holes is in order. This may be accomplished
by strapping or clamping the jig body or lid, as the case may
require, on the lathe face-plate, being careful not to spring it,
and then truing the first button by the use of a centre indicator
or "wiggler," as shown in Fig. 16. The button should then be
Fig. 16.
removed and the hole bored and reamed to the finish size. Then
shift the jig, locate the next button perfectly true, and repeat
the boring and reaming operations ; and proceed in this manner
until all the holes required have been finished. By the use of
INTERCHANGEABLE MANUFACTURING. 47
this method jigs of the greatest accuracy can be successfully con-
structed without trouble and worry on the part of the tool -maker,
and the results in the castings to be machined in them will be a
foregone conclusion.
PATTERNS FOE CASTINGS TO BE JIGGED.
In order to produce good work from intricate jigs, it is abso-
lutely necessary that the castings to be drilled in them should be
of uniform size and shape. To insure this, the patterns from
which they are cast should be of metal in all cases, finished at all
points to the size required ; allowing, of course, for shrinkage
and surplus stock at all points which are to be machined pre-
vious to drilling. 'When perfect patterns are made there will be
no doubt as to the results in the castings.
If the method described in the foregoing for the locating and
finishing of the bushing-holes in small jigs of the accurate types
were more generally known and used by tool-makers, there
would be less worry in the accomplishment of successful results
than is at present experienced in the effort to obtain the same by
methods which are now obsolete.
Besides the locating and finishing of the bushing-holes in the
most accurate manner, the following must be kept in mind in
order that satisfactory results will be attained in jig-making.
All the various parts of such jigs, including the body castings,
should be made sufficiently heavy and strong to withstand all
strain to which they may be subjected when in use. The man-
ner of locating the work within the jigs should be such as to be
positive and to eliminate the possibility of shifting during the
operation of the tools. For instance, it would be ridiculous to
adopt a device of the same strength for fastening a piece in
which a one -inch hole is to be drilled as would be used for hold-
ing a piece in which a one-half -inch hole is required. The means
and points chosen for the fastening of the work within the jigs
and against the locating points should be such as to allow of
rapid manipulation and in no way to interfere with the drilling ;
and, lastly, the design and construction of the tools should be
such as to dispense with all unnecessary parts and labor.
48
TOOL-MAKING AND
LOCATING AND FINISHING DRILL BUSHING-HOLES
IN LAEGE JIGS.
The following method of locating and finishing bushing-holes
pertains to large jigs. As a rule, the castings of large jigs for
machining heavy parts are of considerable size and weight. It is
not always possible to swing them on the lathe face-plate and fin-
ish the bushing-holes by the "button" method; as the cumber-
VERTICAL
ATTACH MEN
FIG. 1?
some shape and unusual size of the body castings interdict the
accurate and positive locating of the buttons and make the task
wellnigh impossible, we are forced to adopt other means which
INTERCHANGEABLE MANUFA CTURING.
49
will allow of accomplishing the result in an easy manner. To do
this we use a universal milling-machine which is equipped with
a vertical attachment. First, we strap the jig body on the table
Fig. 18.
and then locate the holes by using the cross and longitudinal feed-
screw graduations, the vertical feed, a pair of twelve-inch ver-
niers, and a B. & S. height-gauge. The actual work is accom-
plished by first locating and finishing the holes in the upper
surface of the jig body, using a small drill-chuck, as shown iu
Fig. 17, located in the socket of the vertical attachment, and a
short, stiff, centering drill. We space, centre, and drill the
holes to the number required in their approximately correct po-
sition, leaving them somewhat under-size and in their accurate
location to each other. To size and finish the holes, a spindle
should be turned to fit the socket of the vertical attachment and
a small cutter inserted in the protruding end of it. Thus we
4
50 TOOL-MAKING AND
have a small boring-bar, as shown in Fig. 18. We next deter-
mine the distance from the side of the boring-bar to the working
side of the jig body with verniers. We deduct one-half the di-
ameter of the boring-bar and then move the table by means of
the cross and longitudinal feed-screws the distances required in
thousandths, and bore the hole to the finish size. The hole being
finished we make a plug and fit it to the hole and insert it, and
then finish the remaining holes by working from the plug and
the side of the jig, measuring with the verniers from the side and
from the base with the height-gauge. Afterward we may drill
and finish the holes in the other sides of the jig body in the same
manner, merely reversing the jig body or removing the vertical
attachment and working directly from the miller -spindle, as may
be found convenient.
JIG WOEK ON THE PLAIN MILLIKG-MACHIXE.
While the most satisfactory and accurate results in jig-mak-
ing can always be attained on the lathe face-plate by the " button
method " or on the table of the universal milling-machine by the
vertical attachment, as described in the foregoing, and jobs can
be done that would be wellnigh impossible of accomplishment
by other means, it must not be inferred that the plain milling-
machine is limited in its sphere of usefulness in jig-making.
Practice has proven that this machine tool possesses considerable
utility in this line.
As the greater number of jigs required are rectangular and
have bushing-holes let in parallel with the sides, and not infre-
quently the bushing-holes are located in all sides of the jig body,
with each side used in turn as a bottom to set the jig on when
drilling from the opposite side, it will be apparent that a large
part of the work necessary to construct the tool can be conven-
iently done on a plain miller with a table that can be adjusted
vertically. We will say that we have a jig to make with bush-
ings let in from two parallel sides. First we square and scrape
the bottom locating surfaces and then clamp the jig body on the
plain miller-table, setting it square with the spindle and as far
from it as possible, so that we niay have ample room between it
INTERCHANGEABLE MANTJFA CTUBING.
51
and the work. In some cases it may be expeditions to clamp an
angle-plate to the platen at one side of the work square with the
spindle, so as to assist in locating the first hole and proving the
work as we proceed. If holes are to be put in all of the differ-
ent sides and the jig is clamped for locating the holes in the
second side, the tool-maker can establish without trouble the
correct relation between the holes by taking distances from the
angle-plate to plugs inserted in the holes first bored, as per Fig.
19. When the distance from the first hole to the side of the jig
is determined, we add the distance the jig is from the angle -
plate, and thus determine how far the first hole is from the angle -
,Miller
Angle
Plate'
Fig. 19.
plate. With the rest of the work there are a number of ways to
follow, but the most practical is to use the height-gauge to meas-
ure all distances. Another, that is almost as good, is to insert
an arbor in the miller-spindle and feed the table forward until a
piece of tissue paper will just draw out between the arbor and
the angle-plate. Then by means of the dial on the longitudinal
feed-screw run the table forward the required distance. When
the screw on the machine has been determined to be correct, one
can depend on the dial almost wholly for the vertical spacing,
while the platen can be set by calipering to the arbor in the
spindle.
In doing jig work on the plain-miller a parallel can often be
clamped to the side of the jig, from which measurements may be
taken. After the work has been located in place on the table a
miller-vise may be clamped to the platen and a diamond-point
tool clamped in it, with which the test arbor in the spindle may
52
TOOL-MAKING AND
be turned true, as shown in Fig. 20, finishing it to size conven-
ient to use in locating the work both horizontally and vertically.
Then again, a turning-tool may be clamped to the back edge of
the table with a parallel spanning the distance to the first slot in
Jig Body
r\ \ r
Test Arbor' Xo ° l
FIG. 20.
the table, and in this way true a piece of stock which may be
held in a chuck in the spindle. Any tool -maker who has done
much jig work on the miller will appreciate the advantage and
the help in having a test piece in the spindle running perfectly
true, and that in order to accomplish accurate work it is neces-
sary to have all conditions equally accurate and reliable as the
job progresses.
It is sometimes necessary to bore a bushing-hole in a jig at
an angle with one of its sides. To do this correctly on the plain
miller we can set the jig body at the given angle with the angle-
plate — which has been first set square with the spindle — by a
bevel protracter.
HAKDLIKG LAEGE JIG BODIES.
When work is to be handled that is larger than the capacity
of the milling-machine platen, it is only necessary to provide an
auxiliary platen almost as long as the machine table and about
twice its width, and bolt it to the machine. This emergency
INTERCHANGEABLE MANUFA CTUBING.
53
table should be provided with a number of slots or holes for fas-
tening the work to it. Accurately made parallels which just fit
the slots in the table are of great convenience in setting such
large work, while a block with a tongue to fit the slot and nearly
as wide as the table and with its edge milled accurately in line
with the spindle axis is also a help.
After the jig is located and ready for letting in the bushing-
hole (whether on the lathe face-plate or on the table of the uni-
versal or plain milling -machine), finishing should not be done
with drill or reamer, for there will not be one chance in a thou-
sand that the hole will be accurately located. The hole must be
bored to a finish in order to do a correct job.
JIG FEET.
The proper feet for jigs is largely a matter of individual
taste. There are, I believe, quite as many kinds of jig feet as
there are jig designers. Some even go so far as to prefer having
no feet at all on their jigs, and thus obviate the possibility of
trouble with the drill-press table slots.
Figs. 21 to 30 show a number of different kinds of jig feet.
Figs. 21 and 22 are flat-base types ; Figs. 23 to 25, cast feet on
Fig. 21.
Fig. 22.
the base of jigs. Any of these make good feet, the one shown
in Fig. 23 being, of course, easier to make and just as good as
54
TOOL-MAKING.
the others except where a foot of considerable length is neces-
sary. With steel feet all sorts and sizes are used and give satis-
faction. Figs. 26 to 30 are types.
In concluding this chapter it will not be amiss to emphasize
the advisability of becoming practically familiar with the instal-
FIG. 23.
Fig. 24.
lation and operation of the interchangeable system of manufac-
turing. To demonstrate the necessity of mastering the details of
the system, it is only necessary to point out that in the manufac-
turing machine-shop of the present day the efficiency of the ma-
chines or parts turned out can usually be judged by the use that
is made of properly designed and constructed drilling and milling
fixtures and jigs for the production in repetition of the most
Fig. 25.
accurate operations of the work. Although it has been, and is
still, possible to obtain satisfactory results without a large outfit
of such tools, no shop can produce interchangeable parts or du-
plicate machines in large quantities and sell them at a price
which will compete in the open market, unless it has an ade-
quate equipment of special jigs and fixtures, and a man at the
head of it who thoroughly understands their design, construction,
and use.
FIGS. 20-30.
CHAPTER IV.
Types of Simple and Inexpensive Drilling- Jigs ;
Their Construction and Use.
In order to discuss the subject of drilliug-jigs exhaustively,
I think it is best to follow up the chapter devoted to the funda-
mental principles for such work by first taking up the compara-
tively simple class of such tools which are used for the machin-
ing and duplication of parts in which great accuracy is neither
essential nor desirable. As before stated, the main point to be
always considered by the constructor of tools of this class is the
decree of variation allowable in the work that is to be machined.
A
I
bCJ
o c
oc
c
o
cj
Ob
A^
B C
c
C B
i 1 i
-J L_
1 i
i | j
TWO TYPES OF VEEY SIMPLE DEILLING-JIGS.
Fig. 31 is a plain casting with two ribs cast on one side. The
casting is first planed on the sides A A, and a cut is also taken
off the ribs. It is then ready to be drilled. As the holes to be
drilled are clearance holes for bolts and studs, no great accuracy
in the jig is required. The jig for this casting is shown in three
views in Fig. 32, and, as will be
seen, is about as simple and in-
expensive to construct as could
be devised for the work. It con-
sists of one body casting, D, with
six projections on one side for
the locating-points and fasten-
ing-screws. It is first planed on
the top and then strapped on an
angle-plate on the miller-table, and the inside is milled. The
inside of the projections F and E E are finished square with
each other, as they are the locating-points. Holes are then
drilled for the set-screws J and J J in the lugs G G and _H" re-
spectively. These screws are case-hardened. In locating the
55
FIG. 31.
56
TOOL-MAKING AND
holes for the bushings, a casting, planed and ready to be drilled,
is laid out, and the holes are drilled and reamed in the posi-
tion and to the size necessary, so that they will coincide with
those in the part of the machine on which the casting is to be
1
(io%
2)
D
ri
2Ug
h- 1 H
j mill
L
J K
L
1 j< h
K L L L K
Fig. 33.
fastened. This casting is then used as a templet, and by
means of the screws J and I I fastened within the jig. The
holes are then transferred through it to the jig, enlarged, and
reamed to size. The bushings L L L L and K K are then made,
and hardened, lapped, and ground to size, and finally driven
into the jig. The castings are drilled by fastening them within
the jig and resting them on the face of the ribs. This jig is easy
to handle and is a rapid producer.
The jig used for drilling the holes P P and 0, in the casting
Fig. 33, is of a different type and is known as a " box-jig." It
is in design one of the simplest and most reliable of jigs suitable
for drilling work of the class shown, where holes have to be
drilled at right angles to each other. The casting Fig. 34 is
machined at one point only, M M, before drilling, by means of a
gang of mills, the size being exact and the ends square. This
milled surface is utilized as a locating-seat for the work when
being drilled. The jig Fig. 34 is in two parts — the body or box
casting A and the lid E. The body casting is first planed square
on all sides, and the inside at C C finished off to fit the milled
portion of the casting at M M. A cut is also taken off the back
INTERCHANGEABLE MANUFA CTURING.
57
N
°1
III 111
"oT"
°1
■o:
o
:r'i
oj
u
i:ii
II 111
O!
at D for the side-locating point for the work. The lid E is fast-
ened to the body casting at each end by means of the screws and
dowel -pins. Two holes are then drilled
and reamed through the lid E and the
base A for the taper locking-pins 1 I,
which are of Stubs steel and are
milled flat on one side and hardened.
The centres for the two bushings G
G in the side of the jig, and the four
II H H H in the Md are accurately
located by setting the jig on the sur-
face-plate and locating the centres by
the use of a Brown & Sharp© height-gauge. The centres are then
prick-punched, and circles, of the diameter to which the holes are
to be finished, struck around them with the dividers. Now when
holes are to be bored an exact distance apart — that is, to the
smallest possible fraction of an inch — the only way to accoinj)lish
Fig. 33.
this successfully is to use buttons and to strap the jig on the
face-plate of the lathe, and accurately locate them by means of an
indicator; but in a jig where a generous limit of error is al-
lowed, as in this case, a simple and more expedient means may
58 TOOL-MAKING AND
be used. The best and most reliable way is to strap the jig on
the table of the miller and locate the drill true and central with
the reference hole, after which the other holes may be located by
moving the table forward or backward, or raising it the proper
distance, by means of the dial on the feed-screws. In fact, all
bushing-holes in jigs of this kind should be drilled in this man-
ner, and not on the drill -press, as it is pure luck when satisfac-
tory results are attained with the latter method, and that factor
is a poor and unreliable one to depend on. After the bushings
are made, hardened, and driven into their respective positions,
as shown, and the clamping-screw J made and entered into the
lid E, the jig is complete.
To use the jig the casting Fig. 33 is slipped into it so that the
points M M are located at G in the jig. The clamping-screw
J" is then tightened and the two taper-pins entered with the flat
face of each against the work, and each given a sharp blow with
the hammer to locate and hold the Work tightly and positively
in position. The jig is then stood up on the legs B B, and the
four holes OOOO are drilled. It is then turned on its side,
and the two holes P P, Fig. 33, are drilled. The clanrping-pins
J Tare driven out and the screw J loosened, the finished work
removed, and another casting inserted. The use of the taper
locking-pins II, as shown, is one of the quickest and most posi-
tive means for the fastening and locating of work of the class
here mentioned.
The two jigs described embody in design and construction a
number of different practical points which can be adapted for
use in jigs for the drilling of parts which have first been finished
at one or more points, as well as rough castings which have not
been finished at all before being drilled. Of course, for the lat-
ter class of work, except in special cases, jigs of the simplest and
most primitive design are all that is necessary, and they are not
worthy of a detailed description.
A SIMPLE FOTJRTEEN-HOLE DEILLI^ T G-JIG.
Fig. 35 shows a casting used as a leg of a small automatic
machine, and the jig for drilling the holes in this casting is of a
more accurate and complicated design than the two previously
INTERCHANGEABLE MANUFACTURING.
5.9
shown, as the holes drilled in the bosses A B C D are for shafts,
and must be exactly the proper distance apart for the gears,
which are afterward assembled on the shafts, to mesh properly.
The casting, Fig. 35, is first machined to size at four points,
namely, at the top and bottom and both sides of the bosses. In
all there are fourteen holes to be drilled, in the positions shown.
The jig used in drilling the holes is illustrated in three views
in Fig. 36. Fig. 37 is a plan of the jig. These show clearly the
design and construction, and very little description is necessary.
Fig. 35.
The jig proper A is of the box type, and is made with the re-
movable lid D. It is cast with legs on three sides — at both ends,
at B B, and at the bottom, at C C. All sides are first machined
square. On the inside of the jig, at E E E E, are raised spots
for the work to rest on. This allows of quickly finishing the
inside, by merely milling the face of the spots to the height de-
sired. The locating-points for the work are four ; the two ad-
justable locating -screws K H, which are equipped with jam-nuts
1 1, and the points at S S. The adjustable screws should always
be used when castings of the kind shown are to be drilled, as
any variation in the different lots of castings may be quickly ac-
commodated by adjusting the screws. For locking and fasten-
60
TOOL-MAKING AND
ing the work against the locating-points, and within the jig, two
set-screws, K and M respectively, and the eccentric clamping-
lever J are used. The set-screw M holds the casting squarely on
M k ni n b
o o
PLAN VIEW WITH LID OFF,
SHOWING MANNER OF LOCATING,
AND HOLDING WORK.
the raised spots in the jig, and that of K forces it against the
points at 8 8, while by giving the lever J a sharp turn it forces
the casting against the screws H H and locks it in position, there-
by holding the work securely without danger of loosening while
being drilled. The eccentric clamping -lever is rapid in both
fastening and releasing the work. The lid D is located on the
jig by means of the dowel-pins G G, as shown in Fig. 38, and
fastened securely by the swinging clamps L L.
In this jig the holes for the bushings at either end, for drilling
the holes marked G and F respectively in the work Fig. 35, are
drilled in the milling -machine in the same manner used for the
other jigs. But for the shaft-holes ABC and D, after the but-
tons are accurately located, the lid D, Fig. 37, is strapped on the
lathe face-plate, and each "button" positively located with an
INTERCHANGEABLE MANUFACTURING.
61
indicator, and the holes bored and reamed to the finish size for
the bushings P P P P and R R respectively.
When using the jig the lid D is removed and the casting in-
serted within the jig, as shown as Q, Fig. 36. The lid D is then
replaced, locating on the dowel-pins G G, and the swinging
clamps L L are tightened. The set-screw M is also tightened and
the eccentric lever J given a sharp turn to locate the casting
tightly in position. The holes at either end are drilled by rest-
ing the jig on the legs B B. The casting is then rested on the
legs G C, and the six holes in the side are drilled. The removal
of the finished work may be quickly accomplished by loosening
the set-screws K and M and the lever J, and then removing the
lid D.
The three jigs shown and described in the foregoing will
serve as practical illustrations of three separate and distinct
nr=o
Fig. 37.
types of jigs, and show how, by the use of simple and inexpen-
sive tools, uniform and satisfactory results may be obtained at
the minimum of cost and to the maximum of production in the
machining of parts in which, as stated before, a limit of error is
allowed.
62
TOOL-MAKING AND
JIGS FOE A BEARING-BRACKET AND BEARING.
Fig. 38 shows a casting of aluminum, used as the upper bear-
ing bracket of an electric cloth-cutting machine. After the hole
in the centre had been bored and reamed to fit the bearing, Fig.
40, at K, it was faced off on the front and back. The holes in
the wings were to be all interchangeable with those in the motor-
case of the machine. The four holes around the centre were also
to be interchangeable with those in the bearing, Fig. 39. All
these holes were drilled in the jig Fig. 40. This was made in
two parts, the base A and the lid B. For these patterns and
castings were made. There were four bosses in the bottom for
the work to rest on while drilling. After the base A . had been
faced off on the back, it was strapped in the miller and a cut
taken over the bosses and also over the ends on which the lid
rested. A hole was then drilled in the centre of the base, into
which a plug, E, of tool steel, turned to fit the centre hole in the
work (Fig. 39), was driven. The work was then placed on it and
the stop-pin G let in. The set-screw R having been made, a hole
was drilled and tapped and the screw let in.
The lid B, of cast-iron, after being planed on both sides was
strapped to the top of A, and holes were drilled for the two
Fig. 39.
dowel-pins G G, which were then let through into A, and the
holes in B eased up so that the lid would set in nicely. A and
B were then clamped together and a slot milled through each end
for the locking-posts 1 1. The posts were made and finished and
hinged in A by pins J J. Thumb -nuts were got out and tapped
to screw on to the posts freely. The posts were then swung over
INTERCHANGEABLE MANUFA CT UBING.
63
and the thumb-nuts tightened, thereby clamping the lid and base
together. The jig was then stood up on the side D, which had
been squared with the back, and the centre of the stud E was
found on the lid B with a height-gauge, the holes for the bush-
ings were laid out, centred, drilled, and reamed, and the bush-
FIG. 40.
ings made, hardened, ground, and driven in. The jig was then
complete, and lid was removed, and the work (Fig. 38), was in-
serted, centring itself on the stud E. The set-screw B was
tightened until the work was forced up against the stop -pin G,
the lid B was replaced, the dowel-pins C C locating it, the lock-
posts were swung up, the nuts tightened, and all the holes
drilled, which completed the operation. As will be seen, there
is just enough space between the bottom of the lid and the work
for clearance, which was all that was necessary. The centre
holes in the castings being reamed to the size and as nearly as
possible in the centre, thereby fitting the stud E, and the cast-
ings being of uniform size, they were easy to handle. The stop-
pin G and the screw B were sufficient for all requirements of
location. Clearance-holes were drilled in the bosses on which
the work rested, to allow an easy escape for the drillings.
Fig. 41 shows the jig used for drilling the four holes in the
64 TOOL^MAKING AND
bearing, Fig. 39. As stated before, they bad to niatcb those to
the bracket, Fig. 38. The bearing itself was of tool steel, turned
and finished all over to fit the centre hole in Fig. 38. The jig
for drilling was of the box type, made in two sections. L was
the base or jig proper, of round machinery steel, a jriece of which
was chucked and turned on the outside and a hole bored and
reamed to just fit the work at K. It was secured and a thread
of a coarse pitch cut, leaving only two threads. It was then
faced off and undercut at the bottom, to allow the work to set
in, as shown. The lid P was turned and threaded to fit the
piece L nicely ; it was also couriterbored to go over the work
and clamp the face when screwed down solid. The outer edge
was heavily knurled to give a good grip. The work (Fig. 39),
was inserted into one of the finished pieces
(Fig. 38), and the four holes were transferred
m&M
M
L through it, when it was removed and inserted
in the iig L and used as a templet, and the
FIG. 41. J to *
holes drilled through it and through the bot-
tom of the jig L. The top P was then screwed on and the holes
transferred to it. Then they were enlarged for the bushings,
which were made and driven in. This finished the jig. The
work being inserted, the cap was screwed down and the holes
were drilled.
TWO SIMPLE DEILLIIS T G-JIGS AND THEIE USE.
In Figs. 42 and 43 respectively are shown two examples of
the duplication of work by drilling by the use of jigs of the sim-
plest possible construction. The work for the drilling of which
these jigs were used is also shown, both jigs being used on the
same piece of work. Although no great degree of accuracy is
required in the location and size of the holes drilled, the use of
the jigs saves considerable time and insures the desired degree of
interchangeability in the work.
The points drilled in the work by the use of the jig shown in
Fig. 42 are four holes at D D D D, within A A ; and, by the jig
shown in Fig. 43, a hole through each of the legs B B. The
construction and use of these two jigs can be clearly understood
INTEBCHANGEA BLE MANUFA CTVBING.
65
from the illustrations, as well as the manner of locating and fast-
ening them to the work. As shown, the usual conditions are
reversed, the jigs being located and fastened on the work instead
Fig. 42.
of the opposite, which is usually the case. The jig shown in
Fig. 42 consists of seven parts. The bushing and locating-plate
G is of machine steel finished on the ends so as to fit easily into
the portion of the work between A A. The four holes for the
drill -bushings are located and bored and reamed to size, and the
four hardened bushings forced in. A hole is then drilled and
tapped in the centre of the side G to admit the stud E. This
.I.J..L
Fig. 43.
stud has about one inch of thread on the outer end for the fast-
ening nut F, which is finished to the shape shown and the outside
heavily knurled. When drilling, the casting, or work, is stood
66
TOOL-MAKING AND
up on the drill-press table and the jig located between the points
A A, as shown, and the nut F tightened against the opposite
side. The four holes are then drilled through the drill -bushings
and the jig removed by simply loosening the nut F.
The second jig, shown in position on the work and in a side
view in Fig. 43, is of such simple construction that it can be un-
derstood from the illustrations. The three pins 1 1 Jand J J J
respectively, at either end of the bushing-plate G, locate the jig
on the legs B B of the work, and the two holes are drilled
through the bushings H H.
TWO DEILLIFG-JIGS FOR THE SPEED-LATHE.
In Figs. 44, 45, and 46 are shown views of two drill-jigs of
rather novel character, suggestive of ways of drilling a large
variety of different shaped pieces. Fig. 44 is used for drilling
the hole a in the brass piece A (Fig. 45) used for a basin plug,
a rubber washer being afterward fastened around the neck, the
a hole being for the chain ring.
For this jig a piece of 1-inch round machine steel was turned
with a taper-shank to fit the tail-spindle of the speed-lathe,
and a hole was drilled through the body at E. The piece was
then held in a two-jawed chuck, and this hole was enlarged and
bored to the shape shown, so that the piece A would just fit it.
Fig. 44.
The jig was then put in its place in the tail-spindle and the
drill-hole G was drilled. The swinging yoke B: was got out by
forging a piece of steel, machining it to the shape shown, and
fastening by pins I to two flat sides milled on the body of the
jig ; a knurled head-screw J secured the work. A portion of the
INTERCHANGEABLE MANUFACTURING. 67
face of the jig was milled away at iTfor clearance for the yoke
R, to allow it to swing off and on freely.
When in use the jig was set in the tail-spindle and the drill
was held by a small chuck in the live spindle. The yoke H was
swung downward and the work to be drilled was placed in the
jig at F, as shown. The yoke was then swung up and the fast-
FIG. 45.
ening screw J tightened. The tail-stock was then run out, and
the drill entering the hole G, the hole a was drilled. The hole
E through the body of the jig allowed an easy escape for the
dirt and chips.
In Fig. 46 we have another adaptation of this style of drill-
jig, although the construction is somewhat different. It is used
for drilling the hole B B in the screw-plug C. These plugs
were brass castings and were finished all over to the shape
shown in section. The jig for the holes B B consisted of a
piece of 1^-inck round machine steel turned with a taper-
shank to fit the tail stock the same as the other. It was then
put into the live spindle and a hole P drilled to R by using an
extra long drill of the diameter required. The front of the hole
P was nicely rounded with a hand tool to allow an easy entrance
for the drill when the jig was in use. The jig was transferred to
the milling-machine and a section was milled away at M M to the
depth shown, so that the centre of the flange of the work C, when
in position, would be in line with the drill-hole P. A machine-
steel disk N was finished in diameter to fit the hole in the work
C. A hole was let through the centre of this disk, and it was
fastened by the screw O on the flat milled surface of the jig, cen-
tral and in line with the drill-hole P. The spring-pin Q was
made with a spiral spring R at the back and a handle at 8, a
clearance-chanuel T being cut iu, thus allowing the pin Q to be
pulled back and the work released. When in use the work C
68
TOOL-MAKING AND
was located on the jig by the disk N. The tail-spindle was run
out and the first hole B in the flange was drilled to the depth
required. The work was then turned around the disk N until
the hole drilled in the flange was opposite the locatiug-pin Q,
which snapped into it by the tension of the spring B. The sec-
ond hole in the flange was then drilled.
The two jigs here shown for use in the speed-lathe are about
the least expensive that could be devised for the drilling of the
work shown, and it was surprising the amount of work that
FIG. 46.
could be turned out with them. Jigs of this design and con-
struction are very popular in the brass shops, where the speed-
lathe is often adopted for work that is ordinarily done in drill -
presses.
A DEILL-JIG FOE ACETYLENE GAS BTTK^ T EKS.
The work to be drilled was a solid casting of composition of
the shape shown in Fig. 47, which had been dropped in a form-
ing-die under the drop-hammer and then run through a trimming-
die to have each of the same shape and size. After the hole B,
Fig. 47, had been drilled and tapped in the monitor, the piece
was ready for the jig. This is shown from the side and front in
Figs. 48 and 49. N B and Q, Fig. 47, are the holes to be
INTERCHANGEABLE 3IANUFA CTUBING.
69
drilled in the burner. and N were drilled to No. 17, and P
and Q to ~No. 40 drill-gauge size. The small holes were after-
>,N o x
J
B
"p"
E @-
r L--~
G
L
i
Fig. 47.
Fig. 48.
ward soldered at the top, thereby leaving two clear passages for
the gas.
The jig itself was a casting, flat at the back, with three pro-
jections — one at the top to hold the bushings, and two, L and II,
at the base ; also the two lugs L L. In the first place, a piece of
T 5 ¥ -inch thick flat machine steel was planed square to fit the
Fig. 49.
inside of the burner and act as a gauge-plate to locate and
hold it. It was then fastened with the central screw and the
two dowel-pins F F, which were two Stub steel pins filed on the
70
TOOL-MAKING AND
inside of each so that the burner would drop freely, but without
play, between them. Next a taper hole was drilled through the
two lugs E E and the lock-pin D fitted in, with the side bearing
on the work flat. The work B was then put in place and the
lock-pin D driven in, thereby holding the work fast and snug.
The bushings II I J and K were then made, hardened, and
lapped to size. The holes for the bushings were then laid out,
drilled and reamed to size, and the bushings driven in. The
drilling was done in a two-spindle drill. First, the jig was stood
up on the base M and the holes and P drilled, then on the base
L and the holes JVand Q drilled; then, taking out the lock-pin
D, the work was easily removed. The jig worked very satisfac-
torily, each boy drilling from 250 to 1,050 a day. The casting
was sunk in at G to give clearance to the work at B.
DEILLING-JIGS FOE ODD-SHAPED CASTINGS.
The two jigs shown in two views each, in Figs. 50, 51, and
52 respectively, were used for the rapid drilling of the holes in
the castings Figs. 53 and 54, and, as they proved rapid and accu-
L y S L
Fig. 50.
rate producers, the design and construction of them may prove of
interest to those having a number of holes to drill in odd-shaped
castings.
The first jig, Fig. 50, for drilling the casting Fig. 53, is a
INTERCHANGEABLE MANUFA CTURING.
71
very simple and inexpensive type, so constructed as to allow of
the rapid locating and fastening of the work and the removal of
the same when finished. The casting as drilled is shown in two
views in Fig. 53, and has two holes A B drilled in each of the
Fig. 51.
Fig. 52.
eight arms. Before being drilled the castings are chucked in the
turret-lathe, and the centre hole C is bored and reamed to size,
and the hubs are faced.
The jig Fig. 50 consists of two castings, of which J is the
body casting and T the lid. There were openings at all sides
for the escape of the dirt and drillings. The legs L on four sides
and those at M M on back are finished and scraped, so as to be
dead square with each other. The face of the body casting is
also squared with the sides, so that the lid will rest squarely on
it. Two dowel-pins TJ JJ locate the lid, and the thumb-nuts V
V are for fastening it. A stud of tool steel, which is threaded at
both ends and its largest diameter finished to fit snugly the cen-
tre hole C, is let into the bottom of the body casting, as shown at
0, and held rigidly in position by a nut P at the back. A large
hole is bored in the centre of the lid, so as to clear the nut Q.
The sideway locating-point is at B. It consists of a Stub steel
pin, which is hardened and driven into the body of the jig. The
set- screw 8 is also hardened and let in through the projecting
72
TOOL-MAKING AND
lug, and is used for forcing the work against the locating-
pin B.
The four bushings X are let in as shown, and the manner of
locating and finishing the holes was as follows: The body casting
was strapped to the table of the universal milling-machine, and
Ap
A
B
mm
==
C
B J
o
A
aT
the centre of each hole was located, and the hole was finished in
turn by the use of a Brown & Sharpe height-gauge for locating,
measuring from one side of the jig and from the miller-table, and
using a sharp end, mill for finishing, first drilling the hole with a
drill about ^\-inch under size.
The four holes for the bushing W were located by the " but-
ton method, " as described in Chapter III. After being located,
the four holes were drilled and finished to size by strapping the
lid on the lathe face-plate and locating each button to run true
by the use of an indicator.
When using the jig, the lid T was removed by unscrewing the
thumb -nuts V, and the casting to be drilled was located on the
centering -stud 0, the faced hub of the work resting squarely on
the finished boss N. One of the angular-faced projections of the
work is then forced against the locating-pin B by tightening the
set-screw S. The nut Q is then fastened securely within the jig,
as shown by the dotted lines in the plan view of the jig. The
holes B in the projections are then drilled through the bushings
X, that is, through every other one of the projections, by stand-
ing the jig on each of the four pairs of legs L in turn. The jig
is then rested on the legs M and four of the holes A are drilled
INTERCHANGEABLE MANUFACTURING. 73
through the bushings W. The lid of the jig is then removed,
aud the nut W arid the set-screw 8 loosened. The work is then
moved and located so that the holes A and B in each of the four
remaining projections may be drilled. The operations of locat-
ing and fastening the "work and then of drilling the holes are
repeated.
As can easily be seen, the design and construction of this jig
is of the simplest possible character consistent with accurate and
rapid production. Although it is necessary to locate the casting
tw r ice, the time entailed amounts to very little, and is fully com-
pensated for when the simplicity and cheapness of the jig are
considered, as in order to drill all the holes in one operation a
far more complicated jig would have been necessary.
In Figs. 51-52 are shown views of a jig of a rather more elabo-
ate and complicated design than the first. It is used for drilling
the holes in the casting Fig. 53, and finishing the hubs — that is,
the three holes G and the hole through each of the lugs F, the hole
through the hubs at I and the finishing of the hub at H. As
shown in the two views of the jig, the work is located at three
points at each of the finished projections or lugs J, locating
within the parts D, which are drilled to size in a preceding oper-
ation. The work is located side wise against the two adjustable
stops K, by tightening the two set-screws Q against the work.
The lid E of the jig is hinged within the body casting at F by
the pin G. Legs are cast on two sides and on the bottom of the
body casting, as shown at B and C respectivelv. The four
74 TOOL-MAKING AND
bushings L are for drilling the holes through the lugs F, and
those at M, in the lid, for drilling the three holes G. The method
used for fastening the lid while the work is being drilled is
by means of a swinging-stud and a nut and washer I, the stud
being hinged to swing free in the body casting at R, a slot being
let in it and in the lid for that purpose. Two set-screws P are
let into the lid for locating and fastening the work within the jig.
The two large bushings 0, for use when finishing the hubs, are
permanently located within the lid, while those for drilling the
hole I in the hubs are inserted within them when in use. When
using the jig the work is located and fastened within by the set-
screws Q and P, and all the holes are then drilled. The two
bushings N are then removed, and the hubs are faced and re-
duced to size. The fastening set-screws are then released, the
swinging-stud I is thrown back, and the lid raised, after which
the work is removed.
All the various parts of both these jigs, including the cast-
ings, are made sufficiently heavy and strong to withstand all
strain to which they may be subjected when in use. The man-
ner of locating the work is such as to be positive, and without the
possibility of shifting during the operation of the tools. The
means and points chosen for the fastening of the work within the
jigs are such as to be rapid to manipulate, and in no way to in-
terfere with the drilling ; and, lastly, the design and construction
of both jigs are such as to dispense with all unnecessary parts
and labor.
JIG FOE DBILLING BOUGH CASTINGS IK PAIES.
Fig. 56 shows two views of a drill-jig, with work in position
for drilling holes in the tops of rough pairs of bracket castings.
These castings were used in large numbers and were of the shape
shown in Fig. 55. The three holes in the body portion were
cored, and, as the pairs were not machined at any point before
drilling, the holes were used as locating-points in the jig. The
jig consists of a body casting in the shape of an inverted "T,"
X being the base and G the upright which supports the plate E
and the work. The work is located in pairs on either side of the
INTEBCHANGEA BLE MANTJFA CTTJB1NG.
75
upright by the dowel-pins D D D, which enter the cored holes
and are held by the clamping device, a cross-section of which is
shown in Fig. 57. This clamp is of tool steel, with wings at 1
«,
aO
A o
J
Fig. 55.
and J to swing over and clamp the work, the centre portion L
being turned to fit the semi-circular bottom of the slot in the
upright G. A plate R is let into and fastened to the front of the
upright G by the two screws N N. This plate has a stud M fast-
ened in the centre of it, in line with the circular portion L of the
swivel-clamp. The face of the stud is finished to the same
radius as the portion L and is of a length sufficient to allow of the
face acting as a back bearing for the swivel-clamp to swing on.
Fig. 56.
This construction allowed of making the clamp in one piece, and
gave better results than if one of the wings had been made sepa-
rate. About ^ 3 g clearance was given lengthwise to the circu-
76 TOOL-MAKING AND
lar portion L for rapid fastening and releasing when in oper-
ation. The plate E serves as bushing-plate and bushings
as well. It is of tool steel, with three holes at each side as
guides when drilling the holes AAA. The holes G C G are
countersunk to allow a ready entrance for the drill. The plate
is hardened and drawn slightly, after which it is ground on both
sides and the holes lapped. The plate is
located on the body casting by two flat-
head screws F and two dowel-pins not
shown.
When the jig is in use the clamping de-
vice is swung out of the way and a pair of
castings are located on the jig, dowel-pins
I) D D being made an easy fit in the cored holes. The swivel-
clamp is then swung back and the screw K is tightened against
the castings, thus fastening the work against the sides of the
upright G. The six holes are then drilled. This jig allows of the
drilling being accomplished to the required degree of accuracy
and interchangeability and in a very rapid manner. The swivel-
clamp, for fastening the casting against the rib sides, can be
adopted to advantage for locating and fastening work of a vari-
ety of different shapes, whether the parts are sent to the jig
rough or are first machined at different points.
JIG FOE DRILLING AND COUNTERSINKING.
The jig shown in Figs. 59-60 was used for drilling and counter-
sinking the holes D in the casting Fig. 58. The castings before
being drilled are bored at A to a diameter of 1^ inches, and
the hub is faced at b b. The hole D is required to be central
with the rib G. The parts comprised in the jig are: the body
casting, with the circular portion at E, a base at P, and two
feet at B B ; the bushing B G and the locating and fastening
device J I L K and N. The portion E is bored at the front
slightly larger than the hub of the work, and is faced at the back
for the nut N. The bushing G is hardened and ground and
forced into the top. It is lapped to fit a combination drill and
countersink. The locating and fastening device consists of a
INTERCHANGEABLE MA NUFA CTUBING.
77
machine -steel stud with the nut N, and is turned at K to fit a
reamed hole at E, and at F to fit the bored hole in the casting.
Fig. 58.
A half-round groove is let in at L as clearance for the drill. A
large head at J and a washer I with a section cut out at M M
complete it. The work is located on the jig, so that the hole
when drilled will be central with the rib G by entering the rib
Fig. 59.
Fig. 60
into the slot at 0. A slot is let in at Q in the base as clearance
for the end of the work.
When in use the washer I is slipped off the locating-stud and
78 TOOL-MAKING AND
a casting is located. The washer is then slipped over the neck
of the stud and the nut N tightened. The hole D in the work is
next drilled and countersunk. To remove the work all that is
required is to loosen the nut N and slip off the washer.
A JIG FOE DEILLING CAMS.
The cams to be drilled, Fig. 61, were of brass, ^-inch
thick, cut from a bar of 1-inch round stock, the cutting off
being done in the monitor. They were to be drilled eccen-
trically, as shown, with a 4^-inch drill. Of course, to drill a
hole of this size in pieces so small and have all approximately
alike necessitated a jig that would hold them correctly and
securely. The jig is shown in Fig. 62, with a top and an end
view, the top view with the plate for holding the bushing off.
Fig. 63 shows plate aud bushing.
A casting was used for the jig proper, with two wings as
shown, so that it could be set true and strapped on the drill-table.
The bushing-plate was planed on the top and bottom and fastened
with four flat-head screws J and two dowel-pins K. A bushing
L, of tool-steel, with an 4^-inch hole, was then made, hard-
ened, ground, and lapped. The casting, with the plate in posi-
tion, was then set on the face-plate of the lathe, and a hole fl-
inch in diameter bored straight through at E. The hole in the
plate was then bored out so that the
bushing would just drive in. The plate
was then removed without disturbing
the casting, and a piece of turned steel
44 -inch in diameter, with a prickpunch
Fig. 61. b ,
mark exactly ^-mch from the centre,
driven into the hole E in the casting tight enough to keep it
from turning. The casting was then moved sidewise on the
face-plate until the prickpunch ran true. The piece of steel
was then removed and the hole E rebored to 1 inch in diam-
eter and g 9 g-inch full, deep; that is, so that the work, Fig.
61, would enter freely. The casting was then removed from
the lathe and a slot planed in the way shown at N, Fig. 62 ;
that is, 1^ inches wide at the front and running into the
[—"1
INTERCHANGEABLE MANUFACTURING. 79
hole B as shown. A piece of steel, C, ^-inch thick, worked
out in the way shown to keep the work from being bruised,
was then made. A ^-inch taper hole was drilled in A to
admit the lock-pin D, which was of Stub steel, with one fiat
FIG. 62.
side facing the work. The lock-pin and the piece C were both
hardened. G is a bracket of sheet steel cut out and bent in
the way shown and held by screws II; F is the knock-out pin,
if the spiral spring, and this completed the jig. The plate, Fig.
63, was screwed on and the jig strapped to the drill-table. The
work, Fig. 61, was dropped in place, also the piece C, and the
lock -pin I) was given a tap, which held the work fast. The hole
was drilled, the lock-pin removed, and the knock-out hit sharply
80
TOOL-MAKING.
with a hammer, causing the work and piece E to come out
without any trouble, the spring R bringing the knock-out back
in position.
One thing necessary was to have the hole E in the casting and
the hole in the bushing exactly the same size as the drill ; also
the drill ground central, thereby leav-
ing only a very slight burr, as, had it
been otherwise, it would have caused
trouble in removing the work.
The jigs illustrated and described
in this chapter should prove suggestive
for the devising of means for the rapid
and accurate production of different
shaped repetition parts which are to be
drilled. One thing which should al-
ways be kept in mind when designing
or constructing fixtures for interchange-
able production is this : the fixtures used for rough or simple
shaped castings should, if anything, produce quicker and cheaper
than those for machined or perfectly interchangeable ones, be-
cause castings of the first type are, as a rule, sold at such a
low cost that unless they are j)roduced very rapidly no profit is
possible.
Fig. fi3.
CHAPTER V.
Intricate and Positive Drilling-Jigs.
As we are now about to take up descriptions of a class of
drilling -jigs in which the utmost accuracy and inter changeability
in the product are essential, I wish to impress upon the mind of
the reader the necessity of making himself familiar with the fun-
damental principles and the most accurate and practicable means
for accomplishing accurate results in the finishing of the various
parts of such jigs. For this reason I call his attention again to
Chapter III. , in which is contained all that will help the mechanic
to devise and construct accurate drilling -jigs successfully.
JIG FOR DRILLING A MULTIPLE-CAM BODY.
In Fig. 64 is shown a casting with two circles of holes drilled
in face at A and B in the relative positions shown in the pro-
jecting lugs. As this casting, when finished, formed a part of
an attachment for an embroidery sewing-machine, and acted as a
multiple cam, the accuracy of the
holes had to be positive. The jig
used for drilling them is shown
in two views in Figs. 65 and 66,
and as the design and construc-
tion are clearly shown, very little
description is necessary. We will
confine ourselves, therefore, to the
accurate locating and drilling of
the work. D, Fig. 65, is the
body casting, finished on all sides, as shown, the lid L being
hinged on one end, at M. It is then swung on the lathe face-
plate and a hole is bored through both, at Q and E respec-
tively. The hole E is to admit the indexing-plate stem G, and
6 81
Fig. 64.
82
TOOL-MAKING AND
the hole in the lid is for clearance for the clamping-stud Z7and
also as a general point for finishing the bushing-holes. The in-
dex-plate is a forging ; the plate F is of tool steel, and the stems
H and G of mild steel. The stem H is finished to fit snugly the
centre hole in the casting Fig. 64, and is tapped for the clamp-
ing-stud TJ. The stem G fits the hole in the base at E, and is
shouldered and threaded for the washer I and nut J. The plate
proper F is indexed to six and is hardened ; then it is ground and
the notches lapped to a gauge, so that the divisions are spaced to
the utmost accuracy. As a positive locator for the work the best
point is the key way at C, Fig. 64 ; but before letting in the key
in the stem H of the index-plate, Fig. 65, the bushing-holes in
the lid L are finished.
For this operation an arbor is turned up — one end tapering to
fit the driving-head of the universal milling-machine, and the
other a driving fit within the hole Q in the lid. The lid is then
forced onto it and the arbor driven into the head, which is set on
the extension plate facing the spindle. A small centre drill is
first used and the table set to allow of centring the holes on the
.(NAMING 8uA»l>6a
Fig. 65.
proper radius. Three holes, T, Fig. 65, are now drilled, and
then finished to size by butt-mill with a sharp end cut. The
three outside holes S are finished in the same way, and located in
the proper relation to the first circle by using a standard plug,
entering it into one of the holes T and then using the verniers
INTERCHANGEABLE MANTJFA CTURING.
S3
to get the exact distance from it to the side of the end-mill.
When the bushings are finished and driven into the holes, one of
the castings is clamped into the jig, and the index-pin TTlet into
the base of the jig at D is let into one of the index notches.
^
The casting is then adjusted until the holes when drilled come in
the position shown in Fig. 64. The keyway is next located in
the stem H and the casting removed. After the key is let in the
jig is complete. - .
In using this jig the work is clamped in position, as shown,
and the holes drilled through the bushings 8 T S T, which are
directly opposite one another. The index-plate is then moved
one space ; the first two holes drilled are reamed through the two
extra bushings T and 8, and four more holes are drilled through
the other bushings, as before. The principle of this jig can be
used to the best advantage for work in which holes are to be
drilled around an exact radius.
DBILLING- AND HUB-FACING JIG.
Figs. 68 and 69 show two views of jig for drilling the holes
F F F and E and facing the hub D of the casting, Fig. 67. It is
very rapid in handling work, as well as accurate in production.
It can be adopted for finishing work in which rapidity in drilling
is the object sought, as one lever locks and positively locates the
work in position. Before being drilled the casting, Fig. 67, is
machined on the back A , the sides G C, and the channel B, thus
allowing of positively locating it. The jig consists of one cast-
ing, shown at G G G, which strengthens it for the locking-cam
84 • TOOL-MAKING AND
K. The work is located on the two spots H R on the bottom,
and on the sides on the adjustable screws J J, while endwise the
flat piece /locates it by the channel. The three bushings P P P
are let in by the "button" method described in Chapter III, as
is also the hole for the facing-bushing N, while the bushing for
the hole E, Fig. 67, is ground to fit the inside of bushing H.
The clamping- and locating-cam K M and L is made so that
the portion K will press down the work on the spots H H and
carry it against the plate J; while the portion L is finished to a
slight pitch on the inner face — as shown at 8, Fig. 70 — which
forces it against the screws J J. When in nse the work is
Fig. 68.
clamped within the jig, as in Fig. 6S, by pulling down on the
lever M of the locking-cam. The bushing is then removed
and the hub D, Fig. 67, is faced. The bushing D is next in-
serted, and the hole E and also the three others are drilled
INTERCHANGEABLE MANVFA CTUBING.
85
through the bushings F P P. The locking-cam is thrown back
and. the work removed and another piece inserted.
The locating and fastening of work within jigs by the cam-
lock here described is one of the most rapid and reliable means
for accomplishing it, and can be adopted for the drilling of a
Fig. 70.
large number of different-shaped castings where two or more
portions have been machined, so as to get the work at the locat-
ing-points to a uniform size.
AN INTRICATE JIG FOE TYPEWRITER BASES.
As a practical illustration of an intricate jig and the locating
and finishing of a large number of holes to the maximum of ac-
curacy, the jig illustrated in three views in Figs. 72, 73, and 74
will serve as an example. It is used for drilling all the holes —
to the number of fifty-six — in the casting Fig. 71. The casting
86 TOOL-MAKING AND
when finished forms the base of a typewriter and must be abso-
lutely interchangeable.
In work of this kind care should be taken to have all the cast-
ings of uniform size and shape. To accomplish this the pattern
should be perfect and, in all cases of metal, finished at all points
to the size required — allowing, of course, for shrinkage and sur-
plus stock at all the points to be machined. When perfect pat-
terns are made there is no doubt of the result in the castings.
The casting, Fig. 71, is first faced on all projecting lugs and sur-
faces, to gauge, on a profiling fixture. The design and construc-
tion of the jig are clearly indicated in the three views, and the
finishing of all parts in any way similar to those used on the other
Fig. 71.
jigs is accomplished in the same way. The points of sufficient
interest to describe in detail are the manner of locating the work,
the finishing of the bushing-holes and the clamping devices.
The casting rests within the jig on the four legs A A A A,
Fig. 71. It is located endwise against the two points T T", Fig.
72 (these points being milled to the radius of the ends of the
casting which locates in them), and side wise by two adjustable
set-screws B B. The clamping devices are all located on the lid
M and consist of the three knurled head-screws AAA, Fig. 72,
and of the cam-locks Z Z. These locks, shown clearly in Fig.
75, consist of an eccentric turned stud and a square nut, both of
which are hardened and located on the jig as shown. By giving
them a half turn they force the work against the locating-points
INTERCHANGEABLE MANUFA CTUKING.
87
Y T and also against the set-screws B B, and lock securely in
position. The lid is located on the body of the jig by the three
dowel-pins N N N, and clamped by the two swinging-clamps
F N F
! ii i W i
Fig. 72. .
and the large knurled nut P. This manner of fastening con-
tributes to the rapid locating and removal of the lid. The legs
are on three sides of the jig and on the bottom. They are of
■P.
Fig. 73.
tool steel, hardened and lapped in the way before described. In
finishing these legs a number of tool-makers mill a square at the
top — rather an elaborate way ; all that is necessary is to mill a
TOOL -MAKING AND
slight flat on two sides, which answers all the requirements and
is far more expedient.
The most difficult part of the construction is the finishing of
the bushing-holes. By reverting to Fig. 72 it will be seen that
O . P O
Fig. 74.
there are four sets of holes, at B 8 T and U, each set on a
radius central with the centre hole Q. The first hole is that for
the bushing Q, which is finished on the lathe face-plate by the
" button " method. This hole is bored to a size really larger than
necessary, so as to admit an arbor which is located in the divid-
ing head of the miller. This being done with the head facing
the spindle, the first set of holes B are centred and finished in
the position shown by setting the table and head so that the cen-
tre drill is on the proper radius with centre hole Q, and then in-
dexing for sixteen, finishing six holes B and skipping
the centre one. The next row 8 and the rows T and
TJ are finished in the same way by lowering the table
until the centre drill is on the radius required, and
then indexing for twenty-five and finishing eleven
holes on the arc as shown. The lid is then removed
and the four holes V V V V located with buttons,
inserting a standard plug in the holes Q and getting
the distances from it and the side of the jig with a
height-gauge, finally finishing the holes in the lathe.
The holes WWW and X X, and also those in the
side of the jig at E E E E and F F, all go through the same
operation. The manner of locating and clamping the work
in position and then drilling all the holes is clearly shown
Fig.
INTERCHANGEABLE 2LANVFA CT URING.
S9
in the three views of the jig and requires no further de-
scription.
The design and construction of the three separate and distinct
types of jigs shown and described in the foregoing comprise the
best principles for the positive locating, fastening, and rapid
handling of work of the class shown, while the method described
for finishing the bushing-holes is the most accurate that has yet
been devised for accomplishing this part of the work. If fol-
lowed out as defined, the results obtained will be satisfactory
to all concerned.
TWO DEILLIXG- JIGS FOE SMALL, ACCURATE WORK.
In Fig. 77 is shown a drilling -jig embodying a number of
practical ideas. This jig is for spacing off and centring holes
or punch-seats in small wheels, which are in turn used when sup-
plied with punches for perforating leather shoe tips, and miscel-
laneous service of that character. The wheel before drilling is
shown in a cross- section at If, Fig. 76 ; and as finished, with all
holes drilled and counterbored and the punches inserted, at H,
Fig. 76.
Figs. 79 and 80, in which is shown the machine on which the
wheels are used. These wheels are of cold-rolled machine steel
and are finished all over in the turret-lathe.
As the holes or seats for the perforating punches are usually
very small, it is not possible to drill them to the required degree
of accuracy in one jig; so two jigs were used — one for spacing,
locating, and countering the holes, and the other for drilling and
counterboring them. The jig for spacing and centring the
90
TOOL-MAKING AND
hales is shown in Fig. 77, and the jig for drilling and counter-
boring in Fig. 76.
The spacing and centring jig, Fig. 77, consists of a flat-bot-
tomed casting A with two standards B B which support the in-
dexing device. There is a shaft C with a wide shoulder at the
front end to rest against the face of the standard, and an end pro-
jecting from this shoulder to fit the hole in the wheel and threaded
for the nut F. A small pin in the face of the shoulder locates
the wheel iu position on the spindle. The index-plate G has
three circles of holes, the number of the holes being designed for
handling as large a variety of wheels as possible. The index-
pin J is located in a swinging arm H, which swings on a stud
let into a corner of the back standard B. A flat spring K is
fastened to the arm with the end resting in a notch in the index-
pin. Instead of using bushings to guide the drills, a piece of
y^-inch Stub steel is used, it beiug finished with a flat at L with
three holes for the drills. This end is hardened aud the oppo-
site end M is threaded for the adjusting-nut located in the
fork of the bracket N. This adjustment allows of marking dif-
ferent C3mbinations of holes in wheels of different thicknesses
by the use of the one drill guide.
INTERCHANGEABLE MANUFA CTUBING.
91
In conjunction with this drill -jig a small sensative drill is used,
and as the design and construction are clearly shown a detailed
description is unnecessary. The manner of using the jig, Fig.
Gage, for Setting
Counterbore
Fig. 78.
77, is as follows: A wheel D is located on the spindle as shown,
a drill is fastened within the chuck of the press, and the table A
A of the press is set so that it can be raised just high enough to
centre or spot the holes. The index-pin J is then set for the re-
quired circle of holes by swinging and locating the arms H.
After centring the first hole the next is located and centred by
pulling out the index-pin J with the left hand and rotating index-
plate G with the right, the outside of the plate being knurled to
facilitate it.
The jig for drilling and counterboring the wheels is shown in
■ i
FIG. 79.
Fig. 80.
Fig. 76. It consists of a casting Q with a floating spindle 8 on
which the wheels are placed to be drilled. This spindle is fin-
ished on the front end the same as the one used in the first jig,
92 TOOL-MAKING AND
the work being located and fastened upon it in the same man-
ner, the locating-pin TJ entering the hole Y in the wheel W.
Two dowel-pins are let into extreme corners of the bottom of the
jig to coincide with two holes drilled in the table of the drill-
press, so located that the spindle 8 will be in line with the centre
of the drill-chuck. By this means the holes can be drilled very
rapidly and with the certainty that they will all point toward
the common centre. When drilling the wheels, the spindle is
rotated until one of the spotted centres is in line with the drill.
The work is then pressed upward against it and the drill in-
stantly locates it perfectly in line.
The counterboring of the holes is accomplished in the same
manner as the drilling ; the counterbore being set to the required
depth in the holes by means of the groove X, the table of the
FIG. 81.
press being raised until the face of the counterbore rests on the
flat face Y of the gauge, which is slipped into the spindle holes of
the jig. The table is then set, the gauge is removed, the work-
spindle S is reinserted and the holes in the wheel are finished to
the diameter and depth required.
The manner in which the wheels are used when finished is
shown in Figs. 79 and 80. R is the wheel with the punches in-
serted ; I is the pinking-cutter for pinking the edge of the work ;
A the body of the machine ; B the cutter and disk spindle, which
is rotated by hand by the crank handle F ; Y a hard-rubber holder
which runs free and can be adjusted on the yoke spindle T and
raised or lowered by the knurled nut 0. A sanrple of the work
produced is shown in Fig. 81.
JIG FOE DBILLING AN ALUMINUM-BASE CASTING.
Fig. 82 shows a base or stand of an electrical cloth-cutter, a
casting of aluminum, 7 ^--inches long. There were eleven holes
to be drilled around the outside. These were for 6-32 screws,
INTER CHANGE A BLE MANUFA CT UBING.
93
and were to hold in place a sheet-steel shoe the size of the
outside of the casting and the inside shown by the dotted line.
There were also six holes drilled in the depressed part I) which
Casting to be drilled
D
Fjg. 82
were for 10-24 tap, and were to hold the standard that supported
the cutter. Then there were three large holes 1-j- inches in di-
ameter by ^-inch deep, with a |--inch hole in the centre, -g-inch
FIG. 83.
deep. There were also four holes drilled within each of these
large ones, for 4-40 screws. These holes were for plates which
held rollers for the machine to travel on.
The jigs used for drilling these holes are shown in Figs. 83
and 85 respectively ; in all there were thirty-five holes, of which
94 TOOL-MAKING AND
twenty -three were drilled in the jig shown in Fig. 83. As will
be seen, the jig is composed of two main parts, the top and bot-
tom. The bottom was a casting, for which a special pattern had
been made, hollowed out on the inside to allow the work J" to be
set in, with clearance all around. There were lugs cast in each
end to accommodate the swinging studs H H. After it had been
planed flat on the bottom it was milled fiat on the inside, and the
gauge-plate K made and fastened with screws and dowels. This
plate was for locating the work, which had previously been
milled out at that point to templet, as seen at D, Fig. 82. The
top plate was then got out of cast-iron, planed on both sides
and slotted on the ends for the lock-pins. The two were then
strapped together, and the holes for the two dowel-pins J J were
drilled and reamed. The pins were made and driven into the
bottom piece F ; then using the centre of the gauge-plate K for a
common centre, all the holes shown were carefully located by the
button method, and then trued and bored in the lathe.
Three holes were drilled in the position shown for the set-
screws J J J. Next, the bushings were all made, hardened,
ground and lapped to size, and driven home. The lock-studs
H H were made of machine steel and the nuts or handles G G,
also of machine steel, got out and put together, and
the jig was complete. When using, the handles G
G were given a turn so as to allow of their being
swung clear of the plate LJ, which was then removed
and the work inserted within the plate jP, locating
itself on the gauge-plate K. The plate E was then
replaced, the lock-nuts G G swung back and tight-
J*- M ened, and the three set-screws J J J also tightened.
When all the small holes were drilled, the large
holes were drilled and counterbored by the com-
bination drill and counterbore shown in Fiff. 84.
^
N
FiG. 84.
N is a fiat drill inserted within the counterbore; L
a screw for adjusting it, and M a screw for holding it.
This is the style of jig best adapted for this class of work.
As will be seen, the work itself is of a shape hard to hold, and
the way shown answered all requirements and could be relied
upon to machine work that would interchange.
INTERCHANGEABLE MANUFACTURING. 95
Fig. 85 shows the jig for drilling the small holes within the
large ones, for the roller-plate screws ; this itself needs little de-
scription to be understood. As will be seen, it was composed of
a flat piece of cold-rolled steel worked into the shape shown, and
two disks turned up to just the size of the
large holes in the base. They were then
fastened one in each end, so as to inter-
change in the large holes. The holes EI3jl5 T IHf^
for the bushings were then laid out, fig. 85.
drilled, and reamed; the bushings made,
hardened, and inserted, and it was all ready. The jig was
placed so that the disks rested in two of the holes L L. The
holes were drilled in each, and one end of the jig was swung
over to hole A and the holes drilled in it. This proved a
simple and reliable means of drilling these and getting them all
alike, as they should be, as the roller-plates were blanked and
the holes in them pierced in the press.
The steel shoe mentioned in the beginning of this description,
for the base, was blanked and pierced in the press. So the
degree of accuracy necessary in the laying out of the holes can
be easily seen when it is understood that they were to go on either
way, and leave an equal margin projecting all around outside the
edge of the castings.
CHAPTER VI.
The Design and Construction of Drilling-Jigs for
Heavy Machine Parts, etc.
CONSTEUCTING LAEGE DEILLING-JIGS.
The introduction of tools and fixtures for-the production of
duplicate parts of heavy machinery and tools has necessitated the
devising of means and the designing of fixtures by the use of
which the part, or parts, to be machined could be handled with
ease and expedition. The result has been that where the proper
design and construction of fixtures has been carried out, the fin-
ished work has proved vastly superior to that done by the old
methods.
In designing and constructing drill-jigs for heavy parts there
are a number of obstacles to be met and overcome, not found in
jigs for the different classes of work shown and described in the
preceding chapters. They are in effect as follows: In the in-
creased size and strength of the jig castings. Then in the locat-
ing- and fastening-points for the work, which must be so situated
as to allow the work to be located and fastened within the jig
quickly, with the least exertion on the part of the operator.
Lastly in the locating and finishing of the drill bushing-holes,
which cannot (as a rule) be successfully accomplished by the
same means used in the construction of jigs for small parts.
JIG FOE DEILLI]S T G A NAILING-MACHINE CEOSS-
HEAD.
The numerous and various jigs shown in the accompanying
illustrations show clearly the most practical design and construc-
tion for the various shaped castings shown. In Fig. 86 are three
views of a cast-iron cross-head for a nailing -machine. This is
finished at three points, at A A, B B, and the bottom C C. The
INTERCHANGEABLE MANUFA CTUBING.
97
holes drilled are eighteen in number ; four at each end at _D ; four
at E, and six at F in the front projection. The jig for drilling
them is shown clearly with the work fastened within it in the
two views in Fig. 87. It consists of one casting with legs at each
D iF
±3
E
Af '___
\OF O OF O OF O/
\B B
B
cf^ D
D
D
O^ TO
Fig. 83.
end at G G. The work is located by forcing it endwise against
the two locators J and irrespectively, by the set-screws L L (see
view, Fig. 88). Four straps, KKKK, fasten and hold down the
work securely on two raised and finished spots in the bottom of
Fifi. 87.
the jig. The bushing-holes are located and finished by the
method described in the beginning of this chapter. When in use
the work is fastened within the jig by slipping it down on the
locating-points and tightening all screws and clamps. The jig is
98
TOOL-MAKING AND
then stood on end on the legs G G and the holes are drilled
through the bushings Q Q, after which it is reversed and the
holes in the opposite end drilled through the bushings P P. The
large holes through the four projections are then finished by in-
serting a boring-bar through the bushings and the cored holes
in the four projecting lugs of the cross-head, in which four cut-
ters are fastened, one end of the cutter- bar being fastened in the
drill-press spindle, and the other end running in and passing
through the hole in the centre of the table, as the bar is fed
down. The jig is as simple as possible, and allows the work
being very rapidly located, fastened, drilled, and removed. The
projecting lugs on the sides for the straps or clamps K K K K
strengthen the ends of the jig, and overcome the tendency to
weakness in the projecting ends. The use of a boring-bar with
four cutters for finishing the holes E, Fig. 86, is both economi-
cal and productive of good results, saving time in the finishing
of the holes and insuring their alignment with each other when
finished. The use of the clamps for fastening the work tends to
the rapid fastening and releasing of the same, as by a single turn
of the nuts they can be swung on or off.
DEILLING-JIG FOE CAST-IEOJST IMPEESSION EOLLEES.
In the two views of the cast-iron impression roller in Figs. 89,
90, we have a piece of work that would be difficult to handle with-
out the use of a jig. The roller is turned and finished in the
INTERCHANGEABLE MANUFACTURING.
99
lathe and then transferred to the miller and indexed for six, and
the four channels T T T T are milled down its entire length. In
each of these channels six holes, R, are drilled and in the plain
uE
Fig. 89.
Fig. 90.
side of the roller four counterbored holes, W, are let in. The
inside of the roller is cored out as shown by the dotted lines,
with cored vents at 7 7. A 2-inch hole through the ends at
U ZJacts as a journal-bearing for a revolving shaft. The jig is
clearly shown in the cross-sectional view in Fig. 91, and in the
top and end views of Figs. 92, 93. X is the main casting, Y the
bushing-plate, and I the shaft on which the roller Z to be drilled
is fastened. The locating-plate C revolves in the end B of the
jig and projects through to the opposite side, the index-plate P
being keyed to it at G and fastened by the nut H. The bush-
ings N are for the six holes R in the channels, and those at M
for the counterbored holes W W, Fig. 90. To locate the roller
within the jig so that the channels in which the holes are drilled
will be in line with the bushings, the locator D is used. It is
fastened within a channel in C by the cap -screw shown, piece
1 N.~J^L.N N N N JLn ■
Fig. 91.
D fitting the channel E snugty, as shown in the cross-section ;
while the roller is fastened to the shaft I by the set-screws K.
In the end view of the jig, Fig. 92, the indexing-holes in the
plate F are shown — those for the holes in the channels are at
R R R, and the one into which the index-pin J is entered, four
100
TOOL-MAKING AND
LffTJPl
Pig. 92.
in all. That for the counterbored holes is at Q. The top view
of the jig shows the position in which the bushings N and M are
located, and the manner of locating the bushing-plate by the four
screws L and the two dowel -pins P P. By
reverting to Fig. 91, the manipulation of the
jig when in use, and the drilling of the work
will be understood. The shaft I and the
roller Z are inserted, fitting between the locat-
ing-plate C and the finished hub on the end
A, with the locator D in the first of the
channels. The shaft I is then slipped through
and set-screw K in the roller tightened. The
jig is then set on the table of a large adjustable multiple
spindle-drill; six of the spindles being set so that the drills
will enter the six bushings N, and four of the remaining spin-
dles so set that the counterbores will enter the bushings M.
The jig is then fastened securely to the press table by cap-screws
through the ends at C. The four holes W (Fig. 84) are then
counterbored, first removing the drills from the other six spin-
dles. The counterbores are then removed, the six drills refast-
ened to the spindles, and the index-plate revolved until the first
channel in the work is under the bushing N. Index-pin J is now
entered and the six holes drilled, when the index-plate is moved
for the next channel and the holes drilled in it, the holes in the
Fig. 93.
remaining two channels being drilled in the same manner. The
use of this jig together with the multiple spindle-drill makes the
handling and drilling of the heavy roller a simple operation,
that would, however, be difficult to perform satisfactorily by
any other means. Moreover, the work produced will be found
to interchange perfectly.
INTERCHANGEABLE MANUFACTURING.
101
DRILLING- JIG FOR DOVETAILED SLIDE-BRACKETS.
A separate and distinct type of jig for heavy work is shown
in thethree views in Figs. 94-95. It is used for drilling all the
holes in the dovetailed slide-bracket shown in Figs. 96-97, and,
as will at once be seen, can be located on the work simply and
Fig. 95.
rapidly. The bracket (Figs. 98, 97) has four holes drilled at
V Y V V and two at W W. The four holes V are for fastening
the bracket to the body of the machine of which it forms a part,
and those at IT IF for fastening a spindle-bearing to the portion
on the bracket. The casting, before being drilled, is machined
on the back at U, planed dovetailed at 8 8, and a cut is taken
off the top at T T. The dovetailed surface is utilized as the
positive locating-point for the jig, as it is shown secured in the
work in the two views of Fig. 95. The bottom of the jig and
the point Z are finished to coincide with the dovetailed surface
of the work. The angular-faced clamp A is forced up against
the work by the two set-screws B B and drawn up tight by the
clamping-lever and stud C. The end locating-point is at I),
which consists of a flat steel plate fastened to the overhanging
end of the jig by two flat-head screws. The four bushings F F
project down almost to the face of the jig, this being necessary,
as the casting at this point is not machined. When being drilled,
the casting rests on the back Xand the jig is located and fast-
102
TOOL-MAKING AND
ened on it as shown in Fig. 95. The holes drilled, the jig is
quickly removed by loosening the two set-screws B B and the
clamping-lever C, which allows the clamp A to be slid back and
1 r>v <^ 1
r
n
w
o
w
1 1
! 1
s
^v ^ v
—
[zz
s
y _V
1
1
|U-' w
T
II! HI
u
Fig. 96.
the jig removed. The design of this jig gives a practical illus-
tration of how simple and inexpensive tools for the drilling of
heavy parts can be constructed, by choosing the most adaptable
locating-points on the work, and designing the jig castings so as
to have as few points as possible to machine. When locating
and finishing the bushing-holes in this jig, it was first finished at
all points necessary, and then clamped to the slide-bracket, or
work, which was in turn clamped to the miller-table, with the
top of the jig up. The holes were then located and finished by
getting the distances from the machined sur-
faces of the work and using the vertical at-
tachment, thus doing away with the necessity
of first laying out the holes on the work, then
finding their location in the jig. This is a
very good plan to follow when the shape of
the jig castings will not allow of their easy fastening to the
miller-table. Moreover, in getting the distances between the
bushing-holes, the machined surfaces of the work are reliable
points to measure from.
§£
/Si
'J
FIG. 97.
DEILLIFG-JIG FOE EOWEE-PEESS BOLSTEES.
Fig. 99 shows still another jig, in two views. It is for drill-
ing all the holes in the press-bolster shown in Fig. 98. The cast-
ing, as can be seen, is a rather difficult one to handle ; but by the
INTERCHANGEABLE MANUFACTURING.
103
use of the jig the drilling is accomplished with ease and expedi-
tion. The only finishing done on the casting before drilling, is
to plane all sides of the two oblong projections, as shown at A A,
Fig. 98.
B B, and C C, to gauge. The holes drilled are the four D D I) D
and two E E, and one through each of the x>rojections F F F F.
The jig (Fig. 99) is in two parts, the lid and body casting.
Fig. 99.
There are legs on four sides and on the bottom. The casting to
be drilled is located from the two oblong projections on the back,
104 TOOL-MAKING AND
as shown in the plan view, by the locating- spots G I and H and
the set-screws K K and J; the large strap L holding it securely
in the bottom of the jig. The lid is located by the two nuts O 0.
The bushings N through each of the projecting lugs on the face
of the lid, are for the holes through FF F F in the work. The
four bushings B are for the holes D and those at Q Q for the
holes E E. When the jig is in use the work is located and fast-
ened within it, as shown by the dotted lines in the plan view in
Fig. 99. It is then rested on its back and all the holes in the
face are drilled. The holes in the projecting lugs of the casting
at F are drilled by standing the jig on each of its sides in turn
and drilling down through the bushings JV. In this jig the
amount of time taken to locate, fasten, and then drill the work
amounts to very little when the shape and bulk of the casting is
considered. Jigs of this design can be used to the best advantage
for the drilling of heavy castings on which are a number of pro-
jecting lugs, and when holes are drilled in them to a given line,
or in line with each other, as in the case of the casting drilled in
this one.
POINTS TO BE EEMEMBEKED.
In constructing tools of the class described in this chapter a
few things must be considered: first, to construct the tools as
simple as possible and to make them positive, so that they can be
handled by cheap help without the possibility of going wrong.
Also, in choosing locating-points on the work for the jigs, take
the same ones (wherever possible) for all succeeding operations,
thereby eliminating, as far as possible, the margin of error
which may be the result of preceding operations. For instance,
let us consider the upper columns of drill-presses: The first oper-
ation on such parts is the planing of the angular faces of the col-
umns. These faces are then used as locating- and truing-points
for the succeeding operations of milling and drilling. There-
fore, if, when the columns were set upon the planer for the first
operation, they were not set square with the ends, the error was
overcome in the machining of the ends in the next operation.
Another thing, tools of the kind shown should always be made
as strong as possible, so as to withstand rough usage without in
INTERCHANGEABLE MANUFACTURING. 105
any way affecting their accuracy. If the tools are delicate, the
time wasted in caring and looking after them offsets that saved
in the machining of the work by their use. Also have a place
for fixtures where they may be put out of the way when not in
use ; do not have them encumbering the floor, as is all too fre-
quently the case in a number of shops. This will tend to
lengthen their life, and it will not be necessary to hunt all over
the shop whenever they are wanted.
CHAPTER VII.
Drilling-Jigs of Novel Design and Construction.
Having in preceding chapters fully described the most expe-
dient means for accomplishing accurate results in designing and
constructing the more familiar class of drill- jigs, as well as illus-
trated numerous types, I will show in this chapter a number of
jigs of special and novel designs and describe means for their
proper making and rapid operation.
DRILLING HOLES IN A SPIRAL LINE AROUND A
CYLINDER.
Fig. 100 shows two views of a jig used for drilling the holes
A A and B B in the roller Fig. 101. As will be seen, the
two sets of holes are drilled entirely around on a f -inch pitch
FIG. 100.
spiral, right and left respectively. When finished the rollers
have hardened pins inserted in the holes, and act as cams for
106
FlCx. 101.
INTERCHANGEABLE MANUFACTURING. 107
moving small slides of an automatic machine. The jig, Fig.
100, although simple in design and construction, is very accurate
in production, and possesses some novel features seldom met with
in drill- jig design. The jig consists of the body casting, of which
A A are the legs, and B the bush-
iug- and pin-plate. The roller tt 7~.
to be drilled is fastened on the ^^° r
spindle 'D by the nut shown. jpFpii
This spindle moves freely in the £=^^
casting at C. The right and
left worms I and J are cut to a f -inch pitch, and are fastened
to the spindle. The indexer K is of machine steel, indexed
to twenty -six and fastened to the spindle by the set- screws
L. The index-pin Q is fastened within the bracket P and is
finished on the end to fit the index-notches in K, the spring R
keeping it down tight. The worm-stud 0, of tool steel, is fin-
ished to fit the worm snugly ; the head is knurled, and it is then
hardened. The end of the spindle D, on which the work is fast-
ened, is finished with a shoulder at E and two smaller ones at F
F, the space between these two being reduced to a size sufficiently
small to allow for clearance for the drill as it comes through
the work. The drill-bushing T is let in the top B so that when
the spindle projects to its furthest point the first hole drilled
will be the exact distance required from the end of the work.
When in use the work is fastened on the spindle and the index-
pin 8 is placed in the first notch of the index-sleeve K, that is, in
the position shown in Fig. 100. The first hole is then drilled^
The pin is now entered into the next notch and the next hole
drilled. And so on until complete circles of holes are drilled
entirely around the work ; the stud O in the worm feeding the
spindle-back as the holes are drilled. As the last one in the first
circle of holes is drilled, the spindle is slid in by hand and the
stud O enters the worm I. The spindle is then revolved in the op-
posite direction, and the other circle of holes drilled in the
same manner as the first. The work is then removed, and the
spindle fed back to the starting-point; another roller blank is
fastened on the spindle, and the operations repeated as before.
This jig can be adopted for the drilling of holes, on a given
108
TOOL-MAKING AND
pitch, in circular jfieces of work. Bushings to the number of
circles required, may be used. The one thing necessary is to have
them spaced and located exactly the same distance apart ; which
should be the same as the pitch of the worm.
INDEXING -DIAL JIG FOE DEILLING SMALL CAMS.
Figs. 102-103 show three views of a jig in which the indexing-
dial principle is utilized for the rapid drilling of the small cam,
Fig. 104. This jig is so constructed as to allow the work when
finished to be self -releasing. It consists of a body casting A
planed and finished on all sides, and having legs B B scraped.
FIG. 103.
Fig. 102.
Fig. 104.
It is bored to admit the stem D of the index- and receiver-plate
C, which has eight holes F bored and finished to allow of the
work to be drilled fitting nicely within them, and thereby acting
as receivers. The four holes L are the indexing- or spacing-
points, and are all reamed to exactly the same size. The bush-
ing-plate H is fastened by the dowel -pins J J and the two cap-
screws J J. This is done before locating and finishing the bush-
ing-holes. The bushings K K are let into the plate S, as shown,
and are ground and lapped to size. Care is necessary in the
locating and finishing of the bushing-holes to get them in the exact
position required, as it is necessary to have the holes in the cam
INTERCHANGEABLE MANUFACTURING. 109
eccentric to a given size. The index-pin P fits snugly in the
hole in the plate M, and the holes L in the index- or receiving-
plate. The spacing and locating of all holes for the bushings,
index-pin, and receivers for the work are accurately accom-
plished by the "button method" on the dividing-head of the
universal milling-machine, in the manner described in a pre-
ceding chapter. The receiver-holes F are all finished to size
with a special reamer.
When in operation one of the pieces to be drilled is placed in
each of the eight holes or receivers F. The dial is then fed
around until the first two places are under the bushings K K,
when the index-pin P is entered into the hole L and the two
pieces of work are drilled. The index-pin is now removed; the
dial revolved one space, and the index-pin re-entered. This
brings the next two pieces under the bushings. The piece drilled
drops through the jig at E ; the bottom of the jig being cut away
at this point, as shown by the dotted lines. The second piece
drilled remains at G. Now the dial is moved around and the
empty receivers are filled, as the finished work drops out. As will
be readily seen, the design of this jig allows of the continuous
drilling of the work, without loss of time in the removal of same
when finished. Moreover, the placing of the work in the empty
receivers can be accomplished very rapidly, which is one of the
best features of the jig, as this part of the work is quite a factor
in the rapid handling and production of small parts by drilling.
This jig can be used to advantage for the drilling of holes in
small parts which have been previously machined to a uniform
size. For the drilling of work in which great accuracy iu the
product is desired the indexing- or spacing-holes in the dial
should be equipped with hardened-steel bushings, which should
be lapped to a size allowing of a snug fit for the index-pin, thus
insuring the accurate locating of the work and the positive fast-
enings of same while being drilled.
JIGS WITH INDEXING-PLATES.
In the jigs shown in Figs. 106, 108, 109, respectively, we have
two more adaptations of the indexing-dial principle for a sepa-
rate and distinct class of work. These possess features and at-
110
TOOL-MAKING AND
Flu. 105.
tachnients which in design and construction are not found in
any of the jigs previously shown. That shown in Fig. 106 is
used for drilling all the holes (except the centre one 0) in the
spider casting, Fig. 105 ; that is, those
marked B and A, through the project-
ing lugs. The design of this jig is
clearly shown in three views, and the
method of construction can be readily
understood from the description of
the others. When in use the casting,
Fig. 105, is fastened on index-plate H,
Fig. 106, by entering into the stud K,
and then fastened by a nut at L. It
is located against the small projecting piece O. The index-pin TJ
is then entered in one of the holes N by feeding the index -plate
around the desired distance by worm C. The holes through one
of the' projecting lugs B, Fig. 105, are then drilled through bush-
ing P. The jig is now stood on the legs B B B B, and one of the
holes A is drilled through the bushing Q at the back. Index- pin
U is pulled out, the dial fed around one space, and the next two
holes are drilled. Index-pin ZJis equipped with a spring which
keeps it tightly down on the plate. The nine holes M are. clear-
ance-holes for the drill, and are finished slightly larger than the
hole in bushing Q. The index-plate if is a good fit between the
front and back of the jig, to allow it to revolve freely without
play on its face. The bearings for the worm-shaft are cast on
the edge at B B. The main casting is cut away at E, as shown,
in order to allow of the handle F revolving freely.
This jig can be used for drilling a number of different sizes
of castings of the same shape ; that is, with the number of pro-
jections reduced or increased by changing the index-plate, or,
better still, by finishing it with a number of different circles of
holes. This will allow of indexing any number of holes in the
casting to be drilled — within its capacity — or for the drilling of
regularly spaced holes in castings of a circular or irregular
shape. The use of the worm for revolving the index-plate,
although not absolutely necessary, is far preferable — whenever the
quantity of work to be drilled will allow of the extra expense —
INTERCHANGEABLE MANUFACTURING.
Ill
to the usual way of revolving the plate by haud ; for by having a
worm a fair fit iu the hobbecl rim of the index-plate, it contrib-
utes to the strengthening and rigidity of the plate while the
work is being drilled.
In Figs. 108-109 we have the other adaptation of the dial
principle, as used for the finishing of work in a manner entirely
different from any other before shown. The piece machined in
this jig is shown in Fig. 107. It is a drop-forging and is first
machined at three points at the back at A A A on a milling fixt-
ure. The centre hole 8 is bored and reamed to size, and the top
C is faced in a special chuck in the turret-lathe. The remaining
112
TOOL-MAKING AND
operations necessary to finish the piece are all accomplished by
the use of the jig shown in plan and cross-sectional views : i.e., the
drilling of the hole D, Fig. 107, in the centre of each end;
the facing of the top ; the finishing of the parts E by a hollow
mill ; the facing of the wide surface of shoulders F, and the fin-
ishing of the half-round bearings G G. As this jig is of a novel
and special design, a detailed description of the practical points
necessary to its successful construction is essential.
The body or base of the jig is of cast-iron, with a slot B at
either end for clamping it to the drill-press table. The three
raised surfaces E and F F locate the work. The lugs C C are
the side locating-points, and those at D D are for the set-screws
H H. Base A is first planed on the bottom, and the projections
Fig. 107.
are finished to the height shown. It is now strapped on the
lathe face-plate, and bored and threaded for the central locating-
and fastening -stud, which is of tool steel, turned and finished to
the shape shown. This stud is threaded at S to screw tightly
into base A, and at E to fit the centre hole in the work 0, and
is reduced for the rest of its length to the size shown at Q.
Finally, the end C is threaded for the nut V. The locating-points
C C are finished so that when the work is forced against them by
the set-screws H H, it will be in the position shown in the plan
view of Fig. 108. The dial or bushing-plate P is of cast-iron,
finished all over, and bored and reamed in the centre to fit snugly
the locating-stud Q. The holes for the six bushings I IKK
and J J are located and finished to the size required on the
lathe face-plate, care being taken to get the centres of all six on
the radius required, and to space them accurately. Next, the
INTERCHANGEABLE MANUFACTURING.
113
bushings are made, hardened, ground, and lapped to size, and
forced into their respective holes in the plate P.
Before locating the six indexing-holes L, one of the forgings,
Fig. 107, was laid out and strapped on the lathe face-plate, and
Fig. 108.
the hole D at either end bored and reamed to size. This forging
was then fastened within the jig, Fig. 109, and used for locat-
ing the first index-hole in the following manner: Two steel
plugs were turned to size, to lit the bushing 1 1 and the holes
1) D, in the work. By inserting these plugs through the bush-
ings, the bushing-plate P was accurately located rigidly in posi-
tion. The first index -hole' was now drilled through the plate P
and into the projection If of the base A. Next, the hole wa3
section on x y
Fig. 109.
reamed with a taper reamer until the taper-locating or index-pin
N entered to the depth shown by the dotted lines in the cross-
section, Fig. 109. Bushing-plate P was then removed, and the
114
TOOL-MAKING AND
five remaining index-holes L located and reamed to size on the
dividing-head of the universal milling-machine. All the parts
were assembled, as shown in the two views, and the jig was com-
plete and ready for work.
For nse the jig is bolted on the table of an adjustable multi-
ple spindle-drill, and two of the spindles set so that the drills
will enter the bushings II. The arms of the drill-press are
adjusted to bring the spindles into proper line and are then
clamped. The holes D D in the work, Fig. 107, are drilled,
then the drills are removed, the nut V loosened, and the bushing-
plate P is revolved one space. Index-pin N is now re-entered
and nut V tightened, which brings the facing-bushings J J" in
line with the work. The top being then faced, the plate is re-
volved one space and the bushings K are brought in line. Next,
the lower shoulder of the work is faced and the bearings G G
finished, after which the work is removed, another piece located,
f~M B
FIG. 110.
and the operations repeated as before. As will be seen, the use
of this jig insures the accurate finishing of the work and its per-
fect interchangeability. Jigs of this design can be used to the
best advantage on multiple spindle-drills.
INTERCHANGEABLE MANUFACTURING.
115
DRILLING HOLES IN A SPIDER CASTING.
Fig. 110 shows three views of a jig that is self-explanatory,
and is merely illustrated to show how the drilling of a number of
holes in a piece at a given angle to each other may be accurately
accomplished in jigs of the simplest construction. The work,
Fig. Ill, is fastened within the jig
on the stud D as shown in Fig. 110,
and located against the adjustable-
screw J by set-screw K, which allows
of the rapid locating and removal of
the work. When the jig is in use
the nut L is removed, the piece to
be drilled slipped onto the stud and
located on a raised flat surface on the inside. The jig being
stood upon the first pair of legs C C, the first hole is drilled.
It is then stood on the next pair of legs, and another hole drilled,
and then the operation is repeated for the third hole.
Fig. 111.
A DRILLING- AND TAPPING-JIG.
The jig shown in Figs. 112, 113, and 114, was for drilling
and tapping cast-iron hoods of the shape shown in Fig. 115.
There are three bosses projecting from the hood, equal distances
Fig. 112.
apart, and these bosses were to be drilled and tapped to ■§ -inch,
and it was necessary to have them accurately spaced. After
116
TOOL-MAKING AND
Fig. 113.
they were drilled and tapped, a § -inch tube was screwed on to
each of the holes and the tubes were each reamed for a piston,
the three pistons meeting in the
centre, as shown in the bottom view
of Fig. 115. The pistons were
worked by an eccentric and formed
a part of a motor. As will be seen,
a piece of this shape was hard to
handle and required reliable means
for holding it.
The main piece or frame of the
jig was the casting B, well ribbed
and strong, with a good, stiff base
A. After the base was finished it was planed on the front, for the
slide was of cast-iron, and was planed and fitted to slide nicely
within B B. A hole M was then bored in the centre of C and
tapped. Two gibs D D of machine steel were made and fastened
with screws and dowels, and scraped until the slide Cwould slide
freely. The locating-disk K of cast-iron was then made, as
shown in Fig. 114. It was first bored in the centre for the shoulder-
screw A, and then turned and hollowed out to just the size of the
rim of the hood, Fig. 115, leaving a wall all around. The back
was faced off and relieved at O 0. After that it was set up in
the miller and indexed accurately, locating and milling three
y s at F. It was also indexed in thirds at P, to give clearance to
the lugs of the casting. It was then fastened so as to revolve
Fig. 1U.
freely, without play, on the face of the slide G, turning on the
shoulder-screw N. The spring-lock G was then made and fast-
ened to the side of G ; so that, when locked, one of the lugs of
the work would be directly under the bushing Q. The project-
INTERCHANGEABLE MANUFA CTUBING.
117
ing piece of the bashing was fastened, with screws and dowels,
and the bashing driven in. The two studs 1 1 were turned and
threaded at one end to screw on to the shoulder, on the face of
C. They were then tapped out at the other end for the two
screws shown. A hole was drilled and tapped in the centre for
the lock-screw L. The parts were then all assembled and the
hood placed within K, the three lugs fitting into the slots P.
The locking-latch H was swung on, and the plate K moved
around until the lock -pin G, which was equipped with a light
spring, entered one of the T's. The lock-screw L was then
tightened, and the work was held fast. The jig was clamped on
the table of the two-spindle drill -press by a (7-clamp at each end,
and the hole drilled through the
bushing into the work. The jig was
then removed and a stud the size of
the hole entered, through the bush-
ing Q, into the hole in the work.
A hole was then drilled at B and
reamed taper through the slide C
into the back at A, for a tool-steel
pin, which, when inserted through
the taper holes, located the work central with the bushing. The
slide N was then slid over the other end of the jig, and, when
central with the other spindle, it was held there and drilled and
reamed for the hole B as before.
The jig was now ready for work, and it was set upon the
drill-press and the work inserted. The taper-pin was then put
in place, and the first hole drilled ; then, on loosening the lock-
screw L, the disk K was moved around to the next notch, the
screw tightened, and the next hole drilled; and likewise with
the other. The three holes being drilled, a tapping attachment
was inserted in the other spindle, and we were ready to go ahead.
The slide C was moved over, the taper-pin entered into B, and
the tapping accomplished by operating the same as before. The
hood was then finished and removed and another inserted. The
jig was easy to handle and the work was accurately finished.
The idea of drilling and tapping in one operation added to its
usefulness and value.
FIG. 115.
118
TOOL-MAKING AND
A NOVEL DBILL-JIG.
The work to be drilled by the jig here shown was a piece of
steel If inches long, with a & -inch hole reamed through the cen-
tre, and there were sixteen holes, 22-drill-gauge, to be drilled
as shown in Fig. 116; that is, entirely
around on a f-inch pitch helix. Then
there were three holes from A to B, Fig.
116, so that when these were separated, as
shown in Fig. 118, and finished on a milling
rig, they would form two perfectly fitting
cams, which, in a friction-clutch that we
were making, would open and close by
the aid of two fingers, not shown. Fig.
117 shows the jig complete.
A is the table of the drill-press; B a clamp, showing how it
was secured to the table ; C the body, which was of cast-iron,
planed on the bottom, with a hole through it for the shaft LJ;
1
1 ,'
: oa:
°0i
i • '
: :
o
o
KIG. 1J0.
D a piece of flat machine steel, 1^ inches wide by f-inch thick,
bent in the way shown and fastened to the body by two screws
at G and the dowel-pins H. The index-plate J was a piece
of machine steel 2^ inches in diameter, with sixteen grooves
INTERCHANGEABLE MANUFACTURING. 119
milled in it to admit the lock-pin P, and to square the holes
evenly. The worm I was of iron, cut ou a f -inch pitch, with a
cross-groove at 0. The pin R was driven into D and fitted
smoothly the worm as shown. M was the lever for raising the
lock-pin, and N the spring to keep it in the groove in the index-
plate. T was the piece to be drilled, the shaft E
being turned to fit the ^-inch reamed hole, and the
thread cut on the end for the nut S to keep the work
in place for the drilling. F was the bushing, to fit 'No.
22 drill. The index-plate was turned one space at a
Fir 118
time and the pin R would, in the course of sixteen
| -inch spaces, cause the worm J to make one complete turn on the
f -inch pitch, when the pin L would be in line with the first of
the three holes X, and the pin R in line with the slot in the
worm at 0. The pin L was then entered with the first hole, then
the next by pulling the shaft out, and then the last, when it
could be easily broken apart, the holes having all but run into
each other. The worm and index-plate were secured by set-
screws, as shown.
Four different sizes of cams were made, f-inch, -J-inch,
1^-inch and 1^-inch, respectively; and all that was necessary
to alter the jigs was to take off the worm and index-plate and
replace with other sizes.
CHAPTER VIII.
Use of Milling-Machines for Modern Tool-Making,
Interchangeable Manufacturing and
Jobbing-Shop Work.
THE UTILITY OF MILLING -MACHINES.
The development of precision machine tools to the present
high state of efficiency is responsible more than anything else for
the results which are now being attained in the making of tools
and fixtures and devices for interchangeable manufacturing and
the machining of repetition machine parts. The one machine
tool which has contributed more than all others to the attainment
of results in modern tool-making is the milling-machine — plain,
universal, and vertical.
The utility of millers is by no means generally known. To
a remarkable degree they are considered adapted only to tool-
room uses or in making duplicate parts. As not every shop or
factory has need for a strictly. tool-making department, or turns
out interchangeable work, investigation into the many uses for a
miller in finishing ordinary, as well as special, work is not car-
ried out as it should be. That they are capable, with attach-
ments, of performing a wider range of work in jobbing-shops
than perhaps any other machine tool, and at lower cost, is a fact
that is now attracting the attention of progressive managers.
A well-designed milling-machine, properly constructed, is
to-day recognized as one of the most important tools in every
well-equipped machine-shop. Many operations heretofore done
on a planer or shaper are now done much more perfectly and
economically on a milling-machine, and for this class of work
the use of end- or surface-mills has recently come into general
favor, as this form of mill will remove metal very rapidly and
leave the surface in good condition.
120
INTERCHANGEABLE MANUFACTURING. 121
The liorizoDtal-spindle machines in the plain or universal
forms are in general use and familiar to all ; and for many kinds
of work, such as index- milling, or milling of any kind where
work is carried on centres or held in head centre ; making irreg-
ular or form cuts requiring the use of a series of cutters held on
arbor which may or may not be supported by outward-arm;
slot-milling, and a variety of operations called for in every-day
practice, these machines with spindle in horizontal position meet
all the requirements and are most convenient and effective.
Special machines, such as the Lincoln and modified types of
this class, are in use for duplication of parts ; but the two main
types heretofore in use for general purposes have been the hori-
zontal-spindle and the vertical-spindle machines, and, as stated,
each of these classes have their decided points of superiority.
While the milling-machine has no claim to antiquity, the
manner in which it has been adapted and used for all classes of
fine work, and the rapidity with which it is becoming understood,
have more than compensated for its late birth. Although the
youngest of the machine-tool brood, it is now the most univer-
sally used one and can well be placed at the head of them all.
The modern tool-room, where claims are laid to doing good work,
that is not equipped with a universal milling-machine is to-day
a paradox indeed. Still, notwithstanding the fact that nearly all
shops have such machines, their use and manipulation are not
generally understood ; that is, we mean that the large and wide
range of work possible to machine on them is not appreciated
by mechanics in general.
When we state that the use and adaptation of the milling-
machine are not understood as they should be, we do not refer to
its use for the ordinary classes of work, but to special work such
as jigs, tools, dies, and fixtures for the machining of repetition
machine parts and also for economic manufacturing.
As one writer in The American Machinist has aptly said:
"Of all the machines to be found in the modern tool-room the
universal-miller stands pre-eminent. This is the machine of
applied geometry. The combinations and positions obtained by
means of a first-class universal are almost endless. A jig-body
properly set up in a universal may be rotated, swung, twisted
122 TOOL-MAKING AND
around, raised, lowered, moved laterally or crosswise, set to any
angle, drilled, bored, reamed, faced, slotted, profiled, indexed,
and in some cases completely machined and made ready for the
bushings without changing the original setting. There is scarcely
any problem in jig-making, no matter how intricate, that cannot
be worked out on a universal with the greatest ease, and posi-
tive distances, angles, and arcs in every direction are only a mat-
ter of correctly reading the index-plates or wheels."
IMPBOVEMENTS m CONSTBUCTIOK
During the past few years great improvements have been
made in the construction of universal milling-machines, so that
now they are adaptable for a larger variety of work than ever.
As incentives to the further improvements of such machines,
their use has been largely extended and their advantages for cer-
tain classes of work are becoming better understood. It is ap-
parent that the constant aim of the designer has been to increase
the range of universal milling-machines, and the result to-day is
that they are used for a variety of work simply astonishing. The
attainment of these results can directly be traced to specialization
in manufacturing and to the employment of jigs, fixtures, and spe-
cial appliances throughout in the production of the machines.
TWIVEBSAL MILLING-MACHINES.
It is not so long since that the universal milling-machine was
looked upon as a machine useful only for tool work, and a first-
class tool-maker the only man to handle it. In a sense it was
looked upon as a luxury which only a few shops could enjoy.
To-day all this has changed and, while the machine is used for a
larger and better variety of tool work than ever, it is in the pro-
duction of repetition parts that its great value has become ap-
parent. Thus this tendency to the universal use of the machines
has given more and better work to the skilled tool-maker ; for
where large quantities of parts are to be milled, a special jig,
fixture, or a device of some sort is, of course, necessary, in order
that the cost of producing the parts may be reduced to the mini-
mum. There are any variety of parts which can be rapidly and
accurately machined by simple indexing or light -chucking de-
vices on these machines ; and as the economy in the production
INTERCHANGEABLE MANUFACTURING. 123
of even a small number of parts machined, by their use usually
more than pays for the cost of the fixtures there is no good ex-
cuse for their non -adoption.
To-day the proprietor of any machine, tool, or die manufac-
turing establishment who wishes to do everything possible to as-
sure success must see first that his tool-room equipment is as
complete as the demands of his specialty necessitate. He should
also start out to do this with the conviction that it will not prove
merely an additional item of expense, but, on the contrary, a de-
partment which will tend to increase the efficiency of his product.
While the first cost of an up-to-date tool -room equipment is
sometimes staggering to the person who pays the bills, the knowl-
edge that through it he will be able to more than balance the
expenditure in a very short time should set his mind at ease.
The universal milling machines now on the market have been
designed and built to meet all requirements of tool-making and
manufacturing, while the attachments which may be used with the
machines make the doing of a special or an intricate job an easy
matter. With the attachments now in use on the universal miller
for rotary -milling, cam-cutting, rack-cutting, vertical -milling,
under-cutting large gears, and a variety of other classes of work
too numerous to mention, the making of tools of unusual accuracy,
as well as the modern manufacturing of machine parts, can be
carried on without trouble or worry on the part of the mechanic.
"KNEE TYPE" OF UNIVERSAL MILLING-MACHINES.
While fully appreciating the value and adaptability under
certain conditions of the "Lincoln," "Slab," and "Rotary
Planer" types of milling-machines, I devote the space at my
command herein to the ' ' Knee Type ' ' exclusively. This type
of milling-machine, on account of its wide range of work, has
been adapted for tool, die, experimental, and fine machine
work all over the world ; and therefore, as the demand for this
type of milling-machine has exceeded that for all other types
combined, the tendency among the manufacturers of such ma-
chines has been to increase their range and to make them uni-
versal in every sense of the term.
The- knee-type milling-machine is among the latest additions
124 TOOL-MAKING AND
to the machine-tool family; but it has taken its place in thou-
sands of progressive shops, where it is used to the best advan-
tage as far as the knowledge of the art has progressed at this
date, although there yet remain many shops where its advantages
are not understood, and work is being done on other machines,
or by hand, when it could be done on a milling-machine at a
great saving in cost, if a little thought were given to the proper
cutters and equipment.
The knee-type universal milling-machine will do a greater
variety of work than any other machine tool, and a small experi-
mental shop that can have only one machine will be best equipped
with a machine of this class.
MILLING-MACHINES COMPAEED WITH OTHER
MACHINE-TOOLS.
Any work that can be done on the face-plate or in the chuck
of a lathe can be done in a milling-machine by holding an ordi-
nary lathe-tool in the swivel-vise. A pair of bevel-gears, for
instance, can be bored, turned on the angles, teeth cut, and the
gears finished complete without ever having been near a lathe.
A steam- or gas-engine cylinder can be bored, faced, and finished
complete, and the fly-wheel bored and turned iu the same ma-
chine.
What a trying thing it is to see a machinist work up a num-
ber of parts on a shaper or planer and then see another spend
a day or two filing and fitting to make them go together, while it
takes a helper five minutes to mix them up and another machin-
ist a long time to sort them out and assemble in their proper
places.
By way of contrast, a boy could have made them absolutely .
interchangeable in the milling-machine, and they could have
been drawn at random from the stock-room and assembled with-
out filing, fitting, or loss of time.
Formerly it was supposed that a milling-machine in the tool-
room constituted a full equipment in this line of machinery, but
lately it is becoming known that improvements have been made
greatly increasing the power of the spindle and feed, as well as
INTERCHANGEABLE MANUFACTURING. 125
adding innumerable conveniences, such as all automatic feeds
constructed so as to be quickly changed from one to the other,
and at the same time being impossible for auy two to engage at
once. The knee being box section, cast without hole through
the top, gives the work-table sufficient rigidity to enable it to
carry much larger work without chatter than would be possible
with the old-style construction, and make many manufacturing
operations not only possible, but economical.
An equipment for the rapid production of finished work on a
milling-machine can be classified under three heads.
First : Strong, accurate machine with ample range and easy
adjustments.
Second: Suitable fixtures for holding the work where the
pieces are large or complicated so that they cannot be held in a
vise or easily clamped to the table — (it takes skill to lay out and
block up work on any machine). A suitable fixture makes it
possible to use less skilled workmen.
Third: Well-designed cutters, and a good cutter-grinder to
keep them sharp.
THE MILLING-MACHINE IN THE TOOL-EOOM.
The fate of many a manufacturing concern rests with its tool-
room, for here are produced the jigs, dies, fixtures, boring-tools,
reamers, etc., suitable for the specialties manufactured.
Do not consider it a necessary evil because it is classed as
non-productive, for it is the equipment of well -designed, well-
made tools that enables machine tools, standard and special, to
come up to their highest efficiency, and place the factory in the
fore-front.
The machine-tool equipment should be all that would be re-
quired to make a complete high-class small machine-shop, and
the tool-making should be confined to it as far as possible rather
than break up machines engaged in manufacturing.
MILLING AN ANGLE-PLATE.
Here the universal milling-machine is at home, provided it
is a first-class machine and equipped with vertical-spindle and
126
TOOL-MAKING AND
rack-cutting attachment. A machine of this kind will have the
greatest possible accuracy, convenience, and range, and will be
found adapted to every variety of tool-room work. A long auto-
matic cross-range on a miller is also desirable, as it makes it an
excellent tool for accurate jig-boring. Fig. 119 shows an angle-
plate used on the face-plate of an engine-lathe for accurately
boring a complicated piece that has two holes at right angles to
each other. The angle-plate was first milled on the edge in
order to provide a surface that would set square on the work-
Fiu. 119.
table. The hole on the back for the lathe-spindle plug was first
bored, and the plate shifted to the position shown. It is obvi-
ous that these two holes will be exactly the same height from the
edge of the plate, and the work when placed upon it will be in
line with the lathe-spindle. If the piece had been a box-jig, a
long boring-bar would have been used and the outer end sup-
ported in the overhanging arm. Usually it is better to make
boring -bars to fit in the taper hole in the spindle, as the chuck
takes up some room. The Chuck method, however, is very con-
venient, as the boring-tool need be only a straight piece.
INTERCHANGEABLE MANUFACTURING. 127
CIECULAE JIG-MAKING ON THE MILLER.
It often happens that an accurate circular-jig is required so
that the two pieces drilled will fit without matching holes. This
can be quickly done, as shown in Fig. 120. Note that the divid-
FIG. 120.
ing-head has cross-slot and side-ears so that blocking and strap-
ping are unnecessary, and the large dividing-wheel insures
accuracy.
VERTICAL-SPINDLE MILLING-MACHINES.
In establishments where large numbers of machines, appli-
ances, and parts of standard shape are produced, the chief desire
is the increasing of .the daily output without increasing the labor
cost. This desire can only be gratified satisfactorily by using
machines which can be kept constantly producing parts of the
same shape and size. It is in shops of this class that the vertical-
spindle milling-machine can be used to the best advantage for all
work that can be produced economically by vertical milling.
As much time, skill, and money have been expended in the
development of this type of miller, the advantages to be gained
through its use are numerous, and are now almost universally
recognized where economic production is imperative. The util-
ity of vertical millers for machining surfaces and parts, once
only thought possible to do on the lathe or on the planer, is
steadily progressing, as the degree of precision to which the
machine has been developed, namely, permanency of alignment
of the spindle with the platen, makes the production of accu-
rate and intricate parts by its use assured. .
128 TOOL-MAKING AND
DOUBT AS TO THE UTILITY OF MILLING-
MACHINES.
To those who are in doubt about the utility of milling-ma-
chines — plain, universal, vertical, and those in combination with
other machines — for modern manufacturing, tool-making, and
machine- jobbing, a trip of inspection through the establishments
devoted to their production would convince them; as in such
shops they " practise what they preach " and have adopted their
own machines for the rapid and accurate production of parts of
machines of the same kind with the most gratifying results, the
machines being used to the exclusion of all other machine tools
on all jobs permissible. Thus in those shops the milling-ma-
chine is practically self -producing, and stands to-day a monu-
ment to the ingenuity and skill of those men who conceived it
and developed it to its present high state of perfection.
CHAPTER IX.
Simple Milling Fixtures.
SIX DISTINCT TYPES OF SIMPLE MILLING
FIXTURES.
Having in preceding chapters described various types of
fixtures and tools suited for machining different grades of dupli-
cate work by drilling, I will now turn my attention to milling
fixtures; and will devote this chapter to those adapted for
machining the simpler grades of work in which no great accu-
racy is required, but which, at the same time, it is necessary to
produce to a certain degree of interchangeability.
In the construction of tools and fixtures for the machining
and duplication of interchangeable machine parts by milling, a
number of obstacles must be overcome that are not met with in
the fixtures and jigs described in preceding chapters. There are
also, of course, a number of practical points in their design and
construction which are absolutely essential to their successful
operation ; the conditions under which they are operated being
totally different from those under which drilling- jigs and fixtures
are used. It does not require as high-grade skill to construct
fixtures for accurate milling as for accurate drilling, yet the
designing of these fixtures entails considerably
more thought and practical ability, to give r~[Bp~~-\ i
satisfactory results. /^~~\ \ E?lfl
In Figs. 121, 122, and 123, are illustrated V (®) Ylll
three samples of work milled by the use of in- ^v^_Qj I
expensive fixtures which may be aptly termed B
Fig. Lsl.
' l emergency fixtures. " The fixtures are shown
in 124; 125, and 126. The design and method of construction are
very simple, and are clearly shown in the illustrations. The fixt-
ure for milling the square channel at B B, Fig. 121, is shown in
9 129
130
TOOL-MAKING AND
Fig. 122.
1
E
>
G G
Fig. 123.
Fig. 124. It consists of a square plate L, of f -inch fiat machine-
steel, finished all over; of the central locating-stud J screwed
tightly into the centre of the plate ; of the
end locating-pin K, and of the two dowel-
pins II which coincide with two holes
drilled and reamed to size in one of the
steel jaws of the miller- vise. The channel
L is used as a guide for the cutter, and also
as a gauge for the depth and location of
the cut in the work. This fixture is located
on the inside of the vise-jaw by the dowels
1 1, and the stud J is entered into the reamed
hole A of the work, and one side of the rough-
cast channel B set against the locating-pin K
as shown. The vise is then closed and tight-
ened against the work, and the cutter is set
to enter the guide -chaunel L of the fixture, so
that it will just touch the bottom of it. One end
of the work is then milled; then the work is
reversed on the fixture, so that the finished
channel will locate against the stop-pin R, and
the other end is finished.
The other two fixtures shown in Figs. 125
and 126 are also constructed to locate on the
stationary jaw of the miller -
vise. That shown in Fig. 125
is relatively the same as the first, except that
no stop-pin is required — the work, Fig. 122,
being round and having but one slot, D,
milled in the position shown. The hubs of
the work are faced and the hole G is reamed
to size, the outside being finished to a given
diameter in the lathe before milling. Fig.
126 shows a fixture used for milling the
channel in the face of Fig. 123. The two sec-
tions are of cast-iron. The largest one, Q, has a raised projec-
tion at one end, with a guide-channel B milled central with the
V on the face. 8 8 are the two vise jaw-dowels, and T the
Fig. 124.
Fig. 125.
INTERCHANGEABLE MANUFA CTUBING.
131
side way locating pin for the work. Both these fixtures are
operated in the same manner as that shown in Fig. 124, and
are adaptable for milling a large variety of small machine parts
that are not required in large quantities, or in which a given
limit of error is allowed, thus necessitating the utmost economy
in the expense of the fixtures for their duplication. The efficiency
and practical value of these three fixtures are at once apparent.
FIXTUEES FOE MILLING A BEABING IN A
BEACKET.
A plan and a side view of a simple fixture that can be
adapted for odd -shaped castings are illustrated in Fig. 127.
This fixture is used for milling the bearing and cap -surface of
the bracket, Figs. 128 and
129, to the shape shown at Y
and ZZ respectively, the bear-
ing Y being milled to an ex-
act half- circle of the radius
required, so as to conform
with its duplicate in the cap.
This is afterward fastened to
the bracket aud the bearing
IS MS
w^
V!W
Fig. 126.
Fig. 127.
reamed to the finish size. The fixture consists of one main cast-
ing in the form of an augle-plate. When the base has been fin-
ished, the tongue J fitted to the central slot of the miller-table,
132
TOOL-MAKING AND
and the two holes drilled for the fastening -bolts, the angle-plate
is set up on the miller, facing the spindle. The face is then
milled, ending in a square shoulder at the locating-surface I.
The two clamps C C are then made, and holes drilled in the
FIG. 128.
FIG. 129.
face of the angle-plate to admit their bolts D I). Locating set-
screws E E are then let into the back extension-lug B and
fastening-screws G G let into the front lug, as in plan view, Fig.
127. Both views of the fixtures show clearly the manner of lo-
cating and fastening the work on the fixture. With the use of
this fixture one can rapidly locate and fasten the work, the
clamping arrangements insuring the rigidity of the work when
presented to the cutter. As will be seen, there is a projecting
surface F at the top of the front extension-lug ; the face of this
FIG. 130.
lug is milled square with the face of the fixture, and acts as a
gauge-point for setting the "gang " mill the proper distance from
the locating-face of the fixture. Fixtures of this design should
be used wherever possible, as the small number of parts and
rapid handling commend them.
FIXTUEE FOR USE IN SQUARING THE ENDS OF
DUPLICATE PIECES.
Fig. 131 gives two views of a milling -fixture which is (to the
best of my knowledge) new in design and has possibilities for a
INTERCHANGEABLE MANUFA CTUBING.
133
wide range of work of the type shown in Fig. 130. This work
is a square -threaded screw with duplicate ends. The ends were
required to be squared so as to be exactly in line with each
other, as shown at K K. The fixture is made to accommodate
six screws at a time, and is made in two sections, Fig. 131.
These sections are of cast-iron, finished and squared all over,
and doweled together by pins Q Q, one at either end. The spac-
ing, locating, and finishing of the six work-receivers, two of
which are shown with the work N Niu position, is accomplished
in the milling-machine by means of a special counter-gore. This
finishes them so that a perfect half -form remains in each section,
Fig. 131.
with the shoulder of each at exactly the same distance from
the top of the sections. A cut is then taken off the face of each
section so that the work may be clamped securely. The most
interesting feature of this fixture is the manner of locating the
work within it so that the second operation of squaring the ends
will be accomplished with ease and expedition. This is done by
milling a slot crosswise through the bottom of the sections at the
side of each receiver to accommodate the locating -plates P P P P
P P as shown. These slots, or channels, are so finished by the
use of the graduate-dials on the table feed-screw. of the universal
miller that when the plates P are driven tightly into one of the
sections, and extending into the other (the slots in which must
134
TOOL-MAKING AND
be slightly enlarged to allow of their entering freely), one of the
squared sides of the end of the work milled with a gang-cutter
in the first operation will rest squarely against them. When in
use the six plates P are first removed and the two sides of one
end of the work milled with a gang-cutter. When all have been
treated in this manner the six locating-plates Pare again inserted
in their channels and the ends finished; requiring three opera-
tions, as follows : First, enter the ends of the screws that have
been milled, so that one of the sides rests squarely against the
locating-plate ; then mill two sides of the other end at right
angles with those milled on the first end. Now, by reversing the
,,
FIG. 132.
screws, the remaining two sides of the first end can be finished
square with the other two. This operation is repeated and the
ends again reversed, thereby finishing both ends square and ex-
actly in line with each other. The use of this fixture enables
duplicate parts of the work to be finished exactly alike, and,
what is more, the squaring of the ends, which is usually a slow
and difficult job, is thus accomplished with ease and rapidity.
FIXTURES FOR USE IX SLOTTING AND DOVE-
TAILING SMALL PIECES.
Two examples of a somewhat different type of milling fixture
are illustrated in Figs. 133 and 134. These fixtures are used for
milling the casting shown in two views in Fig. 132, and embody
INTERCHANGEABLE MANUFACTURING.
135
in their design and construction a number of practical points
which are suggestive.
That shown in the two views of Fig. 133 is used to mill the
square channel at E and the slot D, Fig. 132. The drawings
clearly show the method of construction. The work is located
centrally on the stud K, and sidewise against the stop -pin N, the
clamp I* holding it tightly and securely against the face of the
Fig. 133.
angle-plate J. The guide-channels M M M M are for the large
cutters, and LLL L for the slotting-cutters. The angle-plate, or
fixture proper, is well ribbed at the back, as shown at Q Q Q,
and is located true on the miller-table by a "feather" in the
channel cut in the bottom. When used in conjunction with a
set of gang-mills this fixture is a very rapid and accurate pro-
ducer. The guide -channels in the fixture enable one to set the
cutters to take the proper depth of cut and to locate them cen-
136
TOOL-MAKING AND
tral with the hole B in the work, Fig. 132. When in operation
the cut is against the fixture, thereby holding the work rigidly
against its face.
Fig. 134 shows two views of a fixture whim, although very
simple and inexpensive to construct, has much to commend it.
It is used for milling the dovetail in the end of the casting
shown in Fig. 132, and will accommodate six castings at a time.
It consists of the two end angle-brackets B B, the central locat-
ing- and clamping-arbor C, and the locating-bar 0. The end-
FIG. 134.
brackets B B are first bored out and the hubs faced, and then
they are placed on an arbor and the base of each is milled with
the tongues E E in line~with each other. A square hole is now
let into the face of each bracket at F as shown, and finished to
size and in line by clamping both brackets together and forcing
a broach through the unfinished holes. The locating-bar G is of
square tool steel, finished all over for its entire length, to fit
nicely within the holes in the face of the brackets. The width
of the bar is made to fit the square channel E, Fig. 132, previ-
ously milled in the castings or work. When the fixture is in use
INTERCHANGEABLE MANUFACTURING.
137
the bracket B at the right is clamped securely on the miller-
table, and the one at the left slipped off the arbor C. The six
castings I are then slipped on to the arbor with the square milled
channel of each down, so that the locating-bar G rests within
them. The left bracket is then slipped on and the nut K tight-
ened slightly. By tightening the screws in the ends J of the
casting, the channels are clamped to the locating-bar G. Nut II
Fig. 135.
is then tightened securely and the bracket firmly clamped to the
table: By the use of the vertical attachment and of an angular
cutter, the six castings are milled and finished to the shape
shown at jF, Fig. 132, and at K, Fig. 134.
The points to be considered when designing fixtures for mill-
ing in one operation a number of small parts of the type here
shown are as follows : First, the number which can be handled
138
TOOL-MAKING AND
to the best advantage; second, the manner of presenting the
work to the cutters, and, lastly, the most expeditious and relia-
ble means for locating and holding the work rigidly while being
milled.
FIXTURE FOR USE IN GANG-MILLING.
A type of fixture used extensively for gang-milling, where
wide surfaces or a number of depressions are to be milled in the
face of castings that have not been previously machined, is shown
T
t m i
111- Ft-
UU~~h
^Q^-^Q^
in Figs. 135 and 136. Although of the simplest construction, it
represents a useful type of milling fixture for the milling of a
large variety of work that it would be difficult to machine rap-
idly by any other means. This fixture is used for the milling of
H H
H H
Fig. 137.
the type of casting shown at H, Fig. 137, which consists of four
channels H H H H in the face, and of the square channel I in
one end ; requiring two separate operations ; both being accom-
INTERCHANGEABLE MANUFACTURING.
139
plished on the one fixture. Fig. 135 shows a section of the
plan and side view, and also an end view of this fixture which
handled eight castings at once. It consists of one large casting M
having two half-round depressions running down its entire
length as clearance for the projections on the back of the work.
The top is planed true with the base as a squaring surface for
the work, and ends in a square shoulder at N for the work to
locate against. The work is held in position by clamps at R R
so placed as to clamp two castings, as shown at P P. The holes
for the- bolts are counterbored at the back to allow the heads to
clear the miller-table, as at T T in the side view, Fig. 135. The
work is fastened as shown, and the square channel in the end is
milled. When all the castings have gone through this operation,
the four channels are finished by relocating and fastening the
work to the fixture and setting a gang of mills. The cross-slide
of the miller-table is then clamped, the depth of the cut set, and
the castings finished.
FIXTUEE USED m FACE-MILLING.
Another type of simple milling-fixture is shown in the two
views of Fig. 138. Although somewhat similar to that shown in
FIG. 138.
Fig. 135 it is used for a distinctly different class of milling ;
that is, face-milling. The sketch shows it being used for ends V
140
TOOL-MAKING.
V of castings like Fig. 139. This casting is first set up on the
planer and the dovetailed slide-surfaces U U are planed to
gauge. The fixture is constructed to handle two castings at
once, they being located side wise by forcing the side of one of
the dovetailed surfaces Z against the angular-faced locating-lugs
X X X X as shown, and endwise against the squared and
faced projections Y Fat the back. The castings are held in po-
sition by two clamps each, as at C C C 0, and the heads of the
bolts are let into the base, as at A A in the side view. The ends
of the castings are faced by a large cutter-holder, with self -hard -
FlG. 139.
ening steel cutters set into the rim, so that a roughing and finish-
ing cut can be taken at the same time. When one end of the
casting has been faced, they are reversed, relocated, and the
other ends are faced.
When the large variety of machine parts, both small and
large, which can be machined in exact duplication of each other
by the use of just such simple and inexpensive fixtures as are
here shown is considered, it is surprising that these methods of
manufacture had not been adopted more extensively. By this
we mean in the small shop ; for in the large shops, unless the
machines or appliances are manufactured under patents, it is
absolutely necessary to manufacture by the interchangeable sys-
tem in order to meet competition.
CHAPTER X.
Milling-Fixtures for Accurate Work.
FACTORS m THE SUCCESSFUL USE OF ACCURATE
MILLING-FIXTURES.
We are now about to take up a class of milling-fixtures of a
different type from those described in the preceding chapter, in
that they are more intricate and are also capable of producing
more accurate results. When designing these tools there are
three questions to be considered : First, are the parts which are*
to be machined required in large quantities? Second, must they
be finished very accurately, so as to be interchangeable ? Lastly,
can the parts be handled and finished to the best advantage in
the milling-machine?
The first two questions can be answered in very short order.
But in deciding the answer to the last one, the knowledge and
skill of the designer, who is often the constructor as well, are put
to the test. If it is decided that the milling-machine is most
suitable for the work, the following points must then be consid-
ered after the shape and type of fixture have been determined:
The surface by which the pieces are to be located ; the devices
for fastening the work, and the most practical way of presenting
the surface to be machined to the cutter or cutters, as the case
may be.
As types of the most reliable class of milling-machine fixtures
for duplicating small and medium machine parts, there are here
shown five examples which are well designed for the particular
pieces of work for which they are intended. The devices also
are suggestive, in that many of their features can be so modified
as to be applicable to work of other kinds. Methods for con-
structing the fixtures will be described — explaining how they
can be produced within a reasonable length of time and at mod-
erate expense.
141
142
TOOL-MAKING AND
FIXTUBE FOR THE FIRST PIECE OF WORK.
The fixture shown in three views of Fig. 140 is used for fac-
ing the flat surface of the work, Fig. 141. The finishing of the
ends of the piece is accomplished in the lathe, the parts e e, d d,
and the threaded portions being interchangeable. The fixture,
Fig. 140, for facing the flat surface F true with the turned por-
no. 140.
tions of the work, is of few parts, and holds the work rigidly.
As the method of construction is not very intricate, and can
be understood from the illustrations, a slight description will
suffice.
The fixture proper consists of the body castings G, the stand-
ards H between which the work is located, the back projection
I for the fastening- and locating-screws N N and respec-
tively, and the two clamping-lids J J. The lid clamping -screws
L L are fastened in the slot in the standards, as shown in the face
view, by means of Stub steel pins, so that they may be fastened
and released as rapidly as possible. The lids J J are hinged as
shown at K K. The locating-screws are of tool steel and are re-
duced at the ends as shown at P, in the end Adew, and hardened
INTERCHANGEABLE MANTJFA CTTJRING.
143
and equipped with jam-nuts. The tongue T is let into a slot in
the body casting G so as to be perfectly in line with the turned
portion of the work when within the fixture.
The boring of the standards and lids to size, and the facing
of the surfaces M M so that the work will fit between them
FIG. 141.
snugly, is accomplished in the following manner : The base is
first planed and the body casting strapped to an angle-plate on
the drill-press table. A boring-bar is then used with the end
running in the bushing in the table, and the holes are bored and
the shoulders faced. The two screws N N for forcing the work
against the two locating-screws have knurled heads with a
spanner hole as shown, are threaded to screw freely in the
tapped holes, and are also equipped with jam-nuts.
When using this fixture it is clamped on the miller-table with
the tongue T in the slot nearest the spindle. The two lids J J
\ m f P
Fig. 143.
FIG. 143.
are then thrown back and the work located as shown, first tight-
ening the lids, and then forcing the work against the two locat-
ing screws by means of the knurled head-screw NN, and
fastening the nuts to keep them tightly against the work. The
cross-feed of the miller-table is then clamped so that the cutter
144 TOOL-MAKING AND
will remove the amount of stock required ; and the face is milled,
using a large face-cutter, running it so that the cut will be down-
ward, thereby taking the strain off the fastening-screws N N and
keeping the work against the locating-screws 0. The facing
of work of this class in fixtures of the type shown can be accom-
plished to a greater degree of interchangeability and in less time
than by any other means known to the author.
FIXTURE FOR USE IN MILLING THE SECOND PIECE.
In Figs. 142 and 143 we have a milling fixture of a more in-
tricate type, and one which for rapid locating, fastening, and
releasing of the work when finished, would be hard to beat, as
one turn of the screw fastens or releases, as required.
This fixture is constructed for the accommodation
[ d of two pieces at a time, and could, if required, be
constructed for twelve on the same principle. The
fixture was designed for milling work of the shape
shown in Fig. 144. The piece was of machine steel
and was finished, all but the milling, in the turret-
lathe, and was used as a part of an electric cloth-
cutting machine which was being manufactured in large numbers.
The milling consists of a slot through the stem at a and a flat at
either side of the largest circular portion, as shown at b b.
The fixture consists of two castings, P and E, and spring-
chuck devices, of which J J are tool-steel pieces, screwing into
the casting E and carrying the spring- jaws K. These jaws are
forced out against the work by the expanders L L, which screw
into threaded holes in 1 1. The one point in the construction of
this fixture most worthy of a detailed description is the manner
of finishing the locating -depressions F F in the part E. This
part is of cast-iron, with a projecting lug at M which is used
when finished as a gauge for setting the three cutters which mill
the work. This cast-iron block is first planed on all sides, and
one side N finished dovetail, to fit tightly into the dovetailed
channel milled in the body casting P. This channel, by the
way, was milled on the front of the casting and faced, after the
base had been finished and the groove for the tongue was milled,
INTERCHANGEABLE MANUFA CTURING.
145
on the machine on which the fixture was to be used, to guard
against inaccuracy.
The block E was driven into this channel and fastened by-
two screws, shown at F. The position of the centres for the lo-
cating-depressions FFFF were then located so as to be dead
in line with each other by the "button" method described in
a previous chapter. The depressions were finished and holes
bored and threaded at the back by strapping the block E on the
lathe face-plate, truing the "buttons," boring the holes, finishing
the formed depression to exactly the shape and depth by means
of a forming-tool, and then reversing the work and enlarging and
finishing the holes at the back, as shown.
When the fixture is in use, the work is held down on the lo-
cating-face F F by hand, and the expander given a turn by the
handle J. This causes the spring-chuck K to grip the work and
draw it down on the locating -face. The cutters are then set by
the gauge M and the work milled.
DESCRIPTION OF FIXTURE FOE THE THIRD PIECE.
In Fig. 145 there are two views of a piece which is an ideal
job for the milling-machine. It is a cast-iron spindle-bracket,
and the milling operation consisted of facing the fronts and
backs of the two bosses, and finish-
ing the projecting rib H at a cer-
tain distance from centre of hole
Q and at a right angle with the
hole K. Before milling, the hole
Q is bored and one side of the hub
faced in the turret-lathe. The op-
posite side is then faced and the
two holes drilled through g g and FlG ' U -'
one through K. The side j is faced in a special jig and all
points machined are interchangeable.
The milling fixture shown in Figs. 146-147 is designed to
hold two pieces of work at once, and can be constructed for the
accommodation of a dozen, if desired. One casting, A, is all that
is required for this fixture, and is in the shape of an angle-plate
10
146
TOOL-MAKING AMD
with projecting bosses at the front and back at B B as surfacing -
points for the work, and four projecting lugs on the face, of
which E E are for the locating-points and D D for the fasten-
ing screws. For clamping the work in position a device is used
SECTIONAL VIEW, LOOKING AT LEFT END OF FRONT VIEW*
' MOWN 0ELOW
FIG. 146.
which allows the work to be fastened or removed with the great-
est rapidity. It is shown clearly in the sectional view of the
fixture, and consists of a stud M of tool steel, which is turned to
fit nicely the hole J in the work and L in the fixture. It is of
lnJu=tMI P.t\t, S.fJ
Fig. 147.
the same diameter for its entire length and is threaded at the end
P for the nut 8 and reduced as shown in JV to admit the clamp-
ing-washer Q. This washer is of tool steel and is knurled on the
outside so it can be easily removed, and has a section cut out as
INTERCHANGEABLE MANUFACTURING. 147
shown, for slipping it into the reduced channel N of the stud M.
The locating-faces of the lugs E E are faced at right angles with
the stud N, so that when the faced portion J of the work is
forced against the locating-face it will rest perfectly fiat and
bear all over. The fastening-screws U U are reduced at the
ends W W, ending in a square for the washers V V. The head
of the clamping-stud M is milled with a flat on two sides for a
wrench.
When in use, the fixture is clamped to the miller-table with
the tongue C in the central slot. The nuts P of the clamping -
studs are then loosened, the work slipped on as shown, the
clamping -washer Q Q located, and the nuts P tightened by using
wrenches on them and on the end of the studs. The work
is then forced against the locating-lugs E E by the set-screws
U U and milled, as shown, by setting a pair of straddle-mills
for the proper depth of cut and clamping the cross-feed of the
miller-table. To remove the work all that is required is to loosen
the set-screw U U and the nuts P, slip off the washers Q Q, and
remove the work. The rapidity with which this fixture can be
operated and the perfect interchangeability of the work pro-
duced is surprising. The device shown for clamping the work
is far superior to the usual methods adopted.
INDEXING MILLING FIXTURES FOR LAST TWO
PIECES.
As there are a large variety of circular-shaped machine parts
to be milled at different points regularly spaced, I show in the
last two illustrations two types of indexing milling fixtures in
which simple means are used for the attainment of the results
indicated in the sketches of pieces shown in Figs. 148 and 149.
The first of the two fixtures, the one shown in two views in Fig.
150, is used for milling the six equally spaced channels M in the
disk, Fig. 148. The castings for these parts are finished all over
in the turret-lathe to the shape shown, and are then milled two
at a time on the fixture, Fig. 150. The illustrations show a plan
and cross-section view respectively ; as the design and method
of construction can be understood from them, very little descrip-
148
TOOL-MAKING AND
tion is necessary. A is the fixture proper, the work being-
located centrally on the studs E E, which are let into the base
and located for height on the faced surfaces as shown in the
cross-section. The holes in which the studs E E are located are
bored sufficiently large to give clearance for the hubs of the
FIG. 148.
FIG. H9.
work, as shown at D. The high projecting lugs B B B B are
surfaced so as to allow the clamps N JS T JSf JSf, two to each part,
to clamp the work securely. The indexing device is shown in
the plan view and is self-explanatory. The projecting lug at the
FIG. J 50.
right end of the work has a slot milled through it in a central
line with the central locating -studs E E and to the depth re-
cpaired, thus serving as a gauge for the depth of cut.
When in use the work is located and fastened as shown, only
that the indexing-pins are out. A cut is then taken down
INTERCHANGEABLE MANUFA GTURING.
149
through both parts, as shown by the arrows, to XX. The table
is then run back, the clamps slacked, and the work moved until
the index-pins H H enter the channels just milled. Tightening
the screw J of each to hold it securely, the cutter is run through
again and the operation repeated. The work is then removed
by loosening the clamp -bolts and sliding the clamp back ;
provision being made for this by slotting the bolt-holes of the
clamps, as shown at Q Q in the cross-section. By changing the
location of the indexing device, work may be milled with any
number of slots or grooves; in fact, there is an inexhaustible
variety of work for which fixtures of this design can be adopted
with the best results.
Fig. 151 shows two views of a fixture, the use of which dem-
onstrates how work usually produced in jigs on the drill -press
may be machined in a better manner by the use of simple fixt-
tig. 151.
ures on the milling-machine. The fixture is used for counter-
boring and facing the six bosses of the spindle-disk casting
shown in two views in Fig. 149. The points previously ma-
chined are the hole G, the six holes marked P, and the two hubs,
all being finished to interchange. The fixture consists of the
angle-plate A, which has a projecting hub ou either side at I>
and B, and the central locating-stud and the indexing-pin 0.
After the angle- plate is planed on the bottom it is fastened to
150
TOOL-MAKING AND
the lathe face-plate, and the hub D faced. A hole is then bored
straight through the centre of the hubs and reamed to size, and
counterbored to the diameter and depth shown in the sectional
view, for clearance for the hub of the work. It is then trans-
ferred to the planer, where the hub B is faced and the channel
let in for the tongue. . The central locating-stud is then finished
Fig. 152.
so as to shoulder at H, and reduced and threaded at the back
end for the washer Zand the jam -nuts L L, so as to revolve
freely without play within the fixture. The device is now drilled
for the two hardened steel bushings, one at B for the index-pin
and one diametrically opposite at 8. To properly locate these
bushings, the work is fastened on the central stud I and the
hole for the index-pin bushing R is finished, first by drilling
through one of the holes P in the work, which is then removed
and the hole counterbored to admit the bushing B, as shown
by the dotted lines. The hole through the bushing is lapped to
exactly the same diameter as the six reamed holes P in the work.
The index-pin is then made of tools teel — the head being
knurled as shown — then hardened and ground to fit snugly
within the reamed holes P in the work and the bushing B in
the fixture, being located by entering index-pin through
one of the holes P and into the bushing B ; the hole for bush-
ing 8 is finished, and the bushing entered in the same manner as
the other.
To operate the fixture the work is fastened as shown, and the
counterbore located in a taper-sleeve in the miller-spindle.
The longitudinal and cross-feeds of the table are then manipu-
lated until the lead or supporting stud of the counterbore,
Fig. 152, is in line with and can be entered into the bushing 8.
The work is then fed against the cutter until the required amount
of stock has been removed, and the graduated dial on the cross-
INTERCHANGEABLE MANUFACTURING. 151
feed screw set at 0. The table is then moved back, index-pin
O removed, and the work revolved one space or until the next
hole P is in line with the bushing R. The index-pin is then re-
entered and the operation of counterboring and facing repeated,
and so on until all six of the bosses have been machined in repe-
tition.
CHAPTER XL
Miscellaneous Milling Fixtures, and Special Tools
for Similar Work.
A MILLING FIXTUEE FOE DEILL-PEESS TABLES.
In the machining of tables for three- and four-spindle sensi-
tive drill -presses, one fixture is worthy of interest, as it is both
simple and effective for the accomplishment of the work desired.
It is also suggestive for other work. The fixture is used for mill-
ing the dovetail in the table to fit the slide-surface of the base
or lower column, and is shown in two views in Figs. 153-151.
VERTICAL MILLER
It is used, as shown, in the vertical milling-machine. The table-
surfaces of the castings were first planed up, after which they
were ready to be milled. The fixture consisted of one casting
JV T in the shape of an angle-plate. This casting was first planed
on the bottom and the tongues fitted to the slot in the
152
INTERCHANGEABLE MANUFACTURING. 153
miller-table. A cut was then taken off the face, getting it as
true and smooth as possible, as the face of the table located
against this surface. The two gauge-pieces Q and R, respec-
tively, were worked out and fastened to the angle-plate with
dowel-pins and screws, so they would serve as locating-points for
the edges and face of the table. Three holes P P P were
drilled in the base of the angle-plate, as shown, for the bolts
w
V—
I
.mi
i
p -o:
o
Is
n p
LIMIT GAUGE
NOT IN\
Fig. 154.
used in fastening it to the milling -machine table. Holes were
also drilled and tapped in the face for the strap -screws T T T.
Three straps were then made of machine steel and bent at right
angles at one end, finishing them so as to be in the position
shown when clamping the table.
The fixture was then set up and clamped to the miller-table,
as in the position shown in the top view, and a table ready to be
milled stripped to it as shown, resting and being located on the
top pieces Q and R respectively. A screw-jack was then used
to brace the extension part of the table at W, thereby taking up
the downward strain on the table while the dovetail was being
milled. The milling was then finished in two cuts, as shown at
N in the upper view, milling it to fit the limit-gauge shown at
the bottom.
The use of this fixture gives a. practical illustration of one of
the various kinds of work for which the vertical milling-ma-
chine is adaptable, as the operation shown can be accomplished
in one quarter the time which it would take to do on the planer,
154
TOOL-MAKING AND
or on the regular milling-machine — where, in milling the dove-
tail, the table would be strapped to the miller-table, which would
have to be raised and lowered by hand while milling, which is
both hard on the operator and on the machine as well ; as will be
at once understood.
JIG FOFJ MILLING DBILL-PRESS SPINDLE-HEADS.
The jigs described and shown in the following were used for
milling and boring drill-press spindle-heads manufactured by
the interchangeable system, and are both reliable and cheap in
design and construction.
The spindle-head is shown in two views in Fig. 155, and a
slight description will tend to the intelligent understanding of
the requirements and construction
of the jigs. The operations on the
head consisted of, first, the milling
of the dovetailed A to fit the column
of the drill-press; then the cutting
out of the two lugs R, thereby al-
lowing sufficient spring in the spin-
dle-head to tighten it to the column. The hole is then drilled at
G for the clamping-lever. After this is done, the hole D is bored
and finished. This hole must be accurately located, as the pin-
ion, when inserted, must mesh accurately with the rack on the
Fig. 155.
TOP VIEW
JIG FOB MILLING, DRILL PRESS SPINDLE HEADS
FIG. 156.
spindle, and in order for the heads to interchange the jigs must
be accurately constructed. When casting the heads, the holes
for the spindle and pinion are cored sufficiently small to allow
INTERCHANGEABLE MANUFACTURING. 155
of the holes being finished to size, in case of a slight variation in
the location of the holes when cored in the casting.
The jig used for milling the dovetail A in the head is shown
in three views in Figs. 156 and 157 respectively, and is very
simple in both design and construction. It consists of, first, a
large flat casting E, for which a pattern of the size and shape
shown was first made, and stock left
sufficient at all locating-points to al- £ffl
low of finishing. After a casting was
secured, it was first set up on the
planer and the back planed and the
tongues G G fitted to the central slot
of the table of the large milling-machine. It was then
placed on the table of this milling-machine, and clamped
to the table at each end, H H. By viewing the cross-section
shown in Fig. 157 it will be seen that the head is located at
three points I, J, and K. The point I is milled out, as shown,
to a radius approximately the same as that portion of the head
which rests at that point, as shown. The points J and K are
then milled so that the head will rest perfectly parallel on
the jig. In locating castings of the kind shown, the clamping
portion must be located at the strongest point, especially in this
case, as the milling is finished in two cuts, which are very heavy
cuts. As will be seen, this jig is made to accommodate eight
heads, and for clamping these, four studs and straps are re-
quired ; each one clamping two heads, as shown at M M 31 M.
The studs are of machine steel, turned and threaded at each end
and screwed tightly into holes drilled in the jig. As shown, the
straps are of -§-inch flat machine steel-, cut off the proper length
and dressed at each end at the grinder. The nuts H are faced
upon one side and case-hardened. When all parts are assem-
bled as shown, and the eight heads strapped and located in posi-
tion, an angular end-mill, screwed and fastened on to the screw-
arbor, is used for milling them. For gauging the depth of cut,
a double-ended gauge of f -inch tool steel is used, one end to go
in and the other end not to go in. For gauging the distance
from the centre of the spindle hole to the faces of the cutter, a
button-gauge is used, the bottom fitting the spindle hole (which
156
TOOL-MAKING AND
is rough) freely, and the piece of steel in which it is fastened
resting on the table of the miller. The distance from the cutter
to the other end of the gauge being correct, the work is fed in
until the face of the cutter just touches the gauge; the cross-
slide of the table is then clamped, and the table is raised or
lowered, as may be required, until the edge of the cutter rests on
a slight projection on the end of the gauge. This is for locating
the cut approximately central with the spindle hole. The mil-
ler is then started, and the cutter allowed to run through the
entire eight heads. The table is then fed back to the starting
point and raised a sufficient number of thousands until the small
gauge will just go in. The cut is then started and run through,
then the heads are removed and another eight located and
clamped. The operation is then repeated.
MACHINING DRILL COLUMNS.
The tools here shown were designed by the author and used
for machining the upper columns of small, one-spindle drill -
presses. The column is shown in position on the fixtures. The
Fig. 158.
points machined are the finishing of the slide-surface A A for
the adjustable spindle -head ; the milling of the base M and of
the baek P, as shown ; and, lastly, the boring of the hole for
INTERCHANGEABLE MANUFACTURING. 157
the spindle through the column at L and through the spindle-
head.
The milling of the slide-surface is done first in order to have
a reliable surface by which to locate for the following operations.
The body of the fixture is a long casting, B, with a high projec-
tion at each end, the one at E being a
" V" for the body of the column, and
the one at the other end flat and square
with the base, for the head-supporting
bracket I. This bracket is of cast-
irou, cored out at J so that the head
Fit; 159
of the column L will enter it, the in-
ner side of J being open so as to allow of this. The bracket
is fastened to the body casting byfour cap -screws. A feather
C is let into each end in a channel in the base to locate it
in the slot of the miller-table, and it is fastened by bolts
through the holes at D D. Two clamps at Fand G are used to
fasten the work ; F being nearly over the vertical adjusting -screw
N. A knurled head-screw at H forces the head L against the
locating set-screw K in the face of the bracket I and the two
other set-screws E act vertically as locating- and fastening-
screws.
For the milling, a gang of cutters and a special arbor of the
shape shown are used, the angle or first cutter being threaded
with a left-hand thread to screw onto the arbor and force the
other two cutters tightly together. The narrow cutter is to finish
a flat along the extreme edge of the milled surface, and the large
one is for milling the face. The last two cutters are keyed to the
arbor.
The fixture is first bolted to the miller-table, and the work is
fastened upon it, adjusting all locatiDg-screws so that approxi-
mately the same amount of stock can be removed from all parts.
As the variation in the castings is very little, if the first column
has been machined correctly all the others will be. A gauge is
used to set the gang of mills. The work is moved up to the cut-
ters until the face-cutter is removing the required amount of
stock and the angle-cutter is touching the gauge. When the top
is finished, the table is raised and the under side is finished,
158
TOOL-MAKING AND
starting at D D. Before this fixture was designed, the finishing
of the slide A A was done on the planer ; but by this arrange-
ment the same results were accomplished in one-third the time
and to a far greater degree of uniformity.
For facing the base M and the surface P the fixture shown
in Figs. 160-161 was used. This was made for three columns,
Fig. 160.
only one of which is shown. The dovetailed slide -surface pre-
viously machined is utilized for locating and fastening the
columns. The fixture consists of one heavy body casting, with
Fig. 161.
three standards on which the work is fastened. The locating-
surfaces at F F F, respectively, are finished on the planer, one
side at E with a dovetail at the same angle as that of the ma-
chined surface. Two angular-faced clamps G G, with clamp-
screws H, are used for fastening each column. Two straps H H
are also used ; although they are not absolutely necessary.
INTERCHANGEABLE MANUFACTURING.
159
The base M is finished first, doing the entire number of cast-
ings. They are then reversed on the fixture and the backs P are
faced with an inserted tooth-face milling-cutter, which is fast-
ened in the vertical attachment. The
same cutter is used for facing the bases
of the columns.
The boring -fixture is shown in Figs.
162-163, in the side view of which the
work is shown in position, with the
spindle-head attached to the slide-
surface, ready to be bored. The boring
and finishing of the spindle hole in the
head L of the column and in the spindle-head at one and the
same time is necessary in order to insure the alignment of
Fig. 162.
§ i~Tj9 G .
C L | N
V
J
P/1
l :
N
(2P|,
£&
Fig. 163.
those holes. This fixture is rather more intricate and expen-
sive than the two preceding; but the cost was approved by
the result.
The fixture is in the form of a tall angle-plate, with two
standards N projecting from the inside of C for the locating- and
fastening-points. These standards are cored at K, as shown in
the end view, to clear the boring-bar. Bevel-faced clamps R R f
160 TOOL-MAKING AND
with clamp-screws P P, secure the work. There were two bush-
ings, one at the top in D at E, and the other in the base J at H.
The holes for these bushings were cored small in the fixture
when cast, and were bred to finish size on the large drill-press on
which the fixture was to be used. Before boring and finishing
these holes, the other locating- and lining-points on the fixture
were finished, and the piece was strengthened by fastening two
wide and stiff machine-steel straps at the sides, as shown at S 8.
These straps strengthened the fixture considerably and insured
its rigidity.
The bushings E and II were of tool steel, hardened and lapped
-to a good fit on the boring- bar, and then ground on the outside
and forced into their respective holes. There were four lugs F
with hardened set-screws G and check-nuts to resist side-thrust
when boring the holes in I and Q. Large openings in the up-
right at b b and c c were convenient for inserting, fastening, and
removing the cutters from the boring- bar.
The fixture rests on the base B on the table of the large drill-
press, and the work is fastened as shown. The boring-bar is
then slipped down through the bushings, and the table of the
drill-press swung around until the shank of the bar can be driven
up into the drill-spindle. The roughing-cutters are fastened
in the bar and fed down through the holes. The bar is then
raised ; the roughing-cutters are removed ; a finishing set is sub-
stituted, and the holes then finished.
The boring fixture here shown was used only for machining
single-spindle columns; for the two, three, four, five, and six-
spindle frames a special self -driven machine, that might be set
to bore two columns at once, was used. In this machine the
work was located and fastened upon it in the same way as here
shown, the only difference being in the driving of the boring-
bars or cutter- spindles by bevel-gears, aud feeding them through
the holes in the work by a pinion and rack, in relatively the
same manner as on a self-feeding drill-press.
CHIEF FACTOE IX MACHINE MANUFACTURING.
One of the chief factors in modern manufacturing of machine
parts by the interchangeable system is the selection of the proper
INTERCHANGEABLE MANUFACTURING. - 161
machines and tools for the accomplishing of the results desired ;
those that will allow of the rapid machining of the work are, of
course, the ones to use. It is a common sight in a great many
manufacturing machine-shops to see work being laboriously
performed by the use of inadaptable machines and tools, which
could, by the use of a machine more adaptable for it, be accom-
plished with ease and expediency. In fact, I have often seen
machines standing idle while the work which should have been
machined in them was being done in others which were not at all
adapted for it. Thus we learn that in order to get the maximum
of production from the minimum of labor we must always con-
sider and select the machines which are the best adapted for the
work ; as well as pay attention to the designing and construction
of the tools and fixtures for the operations necessary to finish it.
11
CHAPTER XII.
Special Tools, Fixtures and Devices for Machining
Repetition Parts in the Turret-Lateh.
THE USE OF SPECIAL FIXTUEES IN THE TUEEET-
LATHE.
If there is one type of machine tool that, more than any
other, has taxed the ingenuity of the designer and the skill of
the tool -maker to keep it supplied with work, it is the turret-
lathe ; as the numberless varieties and classes of work which this
great factor in modern manufacturing is capable of handling are
enormous. When I state the above I do not refer to the com-
moner classes of work produced in this machine, as the tools for
their repetition and duplication are sufficiently well known and
understood to make their use universal, and descriptions of them
would be superfluous. I refer to the special, odd, and brain-
racking jobs that are constantly coming along, for which the
ever-resourceful tool-maker is required to construct tools so that
the parts may be turned out rapidly and accurately.
For the production of parts in large quantities in repetition,
which can be finished by turning, boring, or facing, no other
machine tool, when equipped with suitable tools, offers the ad-
vantages or is better suited than the turret-lathe, or its elder
brother, the screw-machine. To faciliate the production and
the efficiency of the machines, and reduce the responsibility of
their operators to the minimum, thousands of tool -makers
throughout the country are constantly engaged in constructng
devices, fixtures, tools, and arrangements. It is with these
classes of tools that I propose to deal in this and the following
chapter ; devoting this one to the use of special tools in the tur-
ret-lathe and the next to the use of similar tools in the screw-
machine.
162
INTERCHA NGEABLE MANVFA CTTJRING.
163
It will not be necessary to go into detail in regard to the
standard tools used in connection with, the various devices and
arrangements shown, as their use is well understood, and it
would be digressing unnecessarily to treat them or the machines
in detail. In regard to the special tools, however, too much
cannot be written.
The variety of the tools shown and the description of their
construction and use will warrant a careful perusal by the reader ;
as they will be the means of suggesting modifications of the de-
signs which can be embodied in tools for work other than that
shown in connection with them. Tools of these types are great
reducers of cost of production ; and the ability to devise and
install them successfully is an enviable capability of the modern
tool -maker.
ATTACHMENT FOE FOEMING IEEEGULAE PIECES
FEOM THE BAE.
The turret-lathe fixture shown in the accompanying engrav-
ings is for forming pieces of irregular outline from the bar. It
Fig. 164.
Fig. 165,
is adapted for work having considerable stock to be removed,
and will duplicate the pieces very accurately and leave the fin-
ished surface smooth and free from tool marks. As it is always
164
TOOL-MAKING AND
ready for use and can be fastened in place on the turret -lathe
and set for the results desired in short order, it should find a
place in all shops where the value of the turret-lathe is appre-
ciated.
Figs. 164-165 are front and back views of the fixture com-
plete, while Fig. 166 is a side view, as the fixture appears when
bolted to the back of a turret-lathe cross-slide. The latter view
also shows the manner in which the cutting-tool is presented to
the work.
The fixture proper consists of two main parts of cast-iron, the
round base J and the body casting I, constructed to swivel on it.
FIG. 166.
The front G of the body casting is dovetailed and has a rib _H"for
the steel slide G. The ribs _ZV N act as strengthening ribs for the
front and also as bearings for the pinion and lever-stud 0. The
steel slide G and an oblong opening K allow the rack to project
through the front G and mesh with pinion Q. This allows slide
G to be moved up or down by the lever at the side. The pinion,
INTERCHANGEABLE MANUFA GTURING.
165
stud Q is of tool steel and lias a large head at one end and is re-
duced arid threaded on the other for the lever and fastening-nut
P. The lever and pinion are keyed to the stud.
The front or face of the steel slide G is finished on an incline
at approximately the angle that would be adopted for the front
clearance of a lathe -tool. This is done so as to avoid having
to give this clearance to the cutting-tool, which is fastened to
the face of the slide, and requires clearance on the bottom only.
Fig. 167.
The cutting-tool, as shown in the side and front views, is located
within a smaller channel in the face of the steel slide C, at D, and
is held by means of the large cap-screw F. The cutting-edge of
the tool is sheared off at the angle shown iu the front view, from
A to B, so that it will remove the metal from the work progres-
sively.
The circular portions of the two main castings, Fig. 164, are
so constructed that the body of the tool cau be swiveled, there
being graduations at U U to enable it to be set accurately at the
desired angle with the work. The base J is provided with a
tongue L which fits nicely in the slot for the tool-post in the
turret-lathe cross- slide. The main casting I is hollow in the
center to allow a centre hub of the base to project up through
it. The bolt K, by which the base is secured to the cross-slide,
166
TOOT^-MAKING AND
passes up through this hub aud thus it is not necessary to loosen
the base when swiveling the body casting or tool-head. To Set
the tool-head the two nuts T T at the base studs are loosened,
and the head graduations set to the angle desired. The nuts are
then fastened, and the head is rigidly held in position. The
manner in which the two castings are finished so as to locate true
with each other and swivel, is shown at V V in Fig. 1 66.
As a practical illustration of the manner in which the fixture
is used, there is shown in Fig. 167 a plan view of it as located
and fastened to the lathe cross-slide, with the cutting-tool in
position for finishing from bar stock the taper end of a mild
steel tool-post. For this work a tail-stock, equipped with cen-
tre, replaces the turret usually employed and supports the end
of the piece being formed and also sets the gauge for length.
In machining the part shown in Fig. 16S, the stock is fed out
the required distance, and the spring-chuck jammed. The tail-
centre, which is very hard, enters the bar far enough to support
it. The handle of the fixture is then grasped by the operator
and pulled downward until the lowest point of the cutting-tool
at A is somewhat near the centre of the revolving stock. The
cross-slide of the lathe is then fed forward, and the tool com-
mences to cut until the slide stops against the stop -screw and the
edge of the tool has removed considerable stock. The slide is
now held securely against the stop-screw by the operator x^ress-
ing down hard on the cross-slide lever; then with his right hand
he pulls dowu on the tool -head lever, thereby feeding the cut-
ting-tool downward, and the stock is gradually removed by the
shearing cut of the tool, and the bar is finished, as shown. As
each portion of the tool's cutting-edge removes the metal, it
passes below the centre of the bar and ceases to cut, so there is
INTERCHANGEABLE MANUFA CT TJBING.
167
only a narrow surface of cutting-edge of the tool removing metal
at the one time. The machining of the work is thereby pro-
gressive ; there is no tendency to chatter or mark the work ; and
by having a good stream of oil constantly running on the work,
a fine, smoothly finished surface is the result. As soon as the
entire cutting-edge of the tool has passed below the cenrte of the
bar, the lathe cross-slide is fed back to its former position, and
the cutting-tool raised for the next piece. In order to produce
the best results, the cutting-edges of the tool should be left quite
hard, and be oil-stoned to a perfectly straight and keen edge.
The amount of clearance and shear has also considerable effect
on the results, and must be determined by the quality and nature
of the material which it is desired to machine.
In Fig. 169 is an illustration of a piece of work, the taper
surface G of which is finished by the use of the special fixture.
/ G
Fig. 169.
Fig. 170.
In Fig. 170 is shown a special turret-tool used for supporting the
smaller tapered end H while the other part is being finished.
The stock machined was a f -inch drill-rod, and the long taper sur-
face was required to be finished as smooth and clean as possible,
and slight changes were made in the tool slide to accomplish
these desired results. The slide G of the fixture was replaced
with another that differed from the first only in that the face
was left straight and at a right angle with the cross-slide, instead
of being inclined for back clearance. Thus, when the edge of
the cutting-tool passed by the centre of the stock, the portion
machined would rub against it, and with the stock rapidly rotat-
ing, the friction was sufficient to give quite a polish to the ma-
chined surface.
168
TOOL-MAKING AND
In Figs. 172 and 173 are shown two samples of work, the
formed surfaces of which were machined by the use of the fixt-
ure here shown, and in Fig. 171 is a sketch of one of the cutting-
tools used for them, from which an idea of their construction
may be gained.
The great saving in producing work of this class direct from
bar stock, in preference to using separate castings, has made the
Fig. 171.
turret-lathe as great a factor in the production of machine parts
as the engine-Jarhe. For that reason any method or device
which will add to the capacity of the machine and increase the
sufficient of output should be adopted, and the fixture herein
described is one which will do this. It can be easily adopted for
ij4'
a.
-y
Fig. 173.
work other than of the class shown, such as chandelier and elec-
trical fixture work, where large quantities of ornamental knobs,
joints, and various other parts are produced from large brass
rods or bars ; and, in fact, for producing shaped pieces from the
bar of steel, brass, fibre, or hard rubber.
INTERCHANGEABLE MA N UFA CTUEING.
169
BOX-TOOL FOR THE TURRET-HEAD.
In Fig. 175 is shown the pinion as used in drill-press spindle-
heads, and in Fig. 174 the tools used for the first operation.
These pinions were of cold-rolled mild steel, and were roughed
out and countered at each end in the turret-lathe. The box-tool
shown in Fig. 174 and a cutting-off tool were all that were neces-
sary for it. The box-tool is finished from a mild-steel forging,
which is first centred, and the stem E turned to fit the hole in
the turret, and both ends faced. It was then located on the
C
1
1
1
1
ill
B
j
ill
Fig. 174.
C
Fig. 175.
head centre and set to run true in the steady rest, and the hole
bored in the face for the bushing G, which was of tool steel,
hardened and lapped to size, to fit the stock to be worked. The
set-screw L holds it in position. A hole is then bored and
reamed through the stem E for the centre-drill K, which is
fastened within it by the headless screw M. Two cutting-tools,
I and J respectively, are let into the box as in the position
shown: one, I, for roughing, set slightly in advance of the
other one, J, which finishes. These two tools are hardened, and
drawn to a light-straw temper ; a set-screw for each, on the side,
holds them in position. When using the tool, the bar of stock
is held in the spring-chuck, and the tools J and J", in the box-
holder, set so as to rough down the stem B of the pinion-blank,
Fig. 175, as shown, leaving enough stock to allow of a finishing
170
TOOL-MAKING ANT)
cut being taken in the lathe, and then grinding them to size in
a Lanis grinder. The centre-drill K is set so as to centre the
end of the stem at the same time. The use of the two cutters in
the box-tool, as shown, acts very well, and reduces the time on
the work considerably, removing the stock — as it does — all in
one cut. The fastening of the centre-drill, K, as shown, also
contributes to reducing the time, as well as centring the stem
true.
TWO SPECIAL CHUCKS FOE THE TUEEET-LATHE.
In Fig. 176 are shown two views of a special chuck used for
boring and facing the hubs of cast bevel-gears. This chuck, to-
gether with the one shown in Fig. 178, is used for the machin-
FIG. 176.
ing of gears which are used in large quantities on cheap ma-
chines, and their use allows of the work being produced in a
very rapid manner, and to the degree of accuracy required and
as cheaply as possible. The cross-sectional view of this chuck
with the work in position shows clearly the design and method
of construction. The body K of the chuck is of cast-iron, and
is bored out and threaded at the back to fit the spindle of the
turret-lathe. It is then finished on the face and a clearance-hole
bored at L, and the locating-seat M M for the gear-face fin-
INTER GHA NGEA BLE MANVFA GT XJR1NG.
171
ished, as shown, by using the compound rest, and setting it over
as required. The inside of the chuck is then threaded for the
fastening-lid at P P. This lid is also of cast-iron, finished as
Fig. 177.
shown, with two handles at Q Q and a clearance-hole R in the
centre for the hub of the work. Six pins, two of which are
shown at X X, serve to drive the work, by engaging the teeth of
Fir,. 17
the gear as shown. When in use the chuck is screwed on to the
spindle of the turret-lathe and the lid removed. The gear, as
shown at N, is then placed within the chuck, with the driving-
172 TOOL-MAKING AND
pins within the teeth. The lid is then screwed on and forces the
bevel- face of the gear against the locating-surface M M of the
chiK'k, truing it and holding it securely. The hole is then bored
at 0, and the hub faced by the use of the combination tool
shown in Fig. 177. By the use of this chuck, the hole in the
gear is bored and finished true with the gear-face, which iu cast-
iron gears is absolutely necessary, in order for the gears to run
well when assembled.
The chuck shown in Fig. 178 is of a much simpler design
and construction; but is just as useful and rapid in production
for the class of work for which it is used as the other. It
consists of one body casting A which is bored and threaded at
back to fit the turret-lathe spindle, and bored on the face of the
clearance-hole at G and at B B as a truing point for the gear-
face of the work F. The work is fastened in position by the two
clamps 1 1. The spring E around each of the clamp-studs con-
tributes to the rapid locating of the work and its removal when
finished. The work is driven by the stud steel pin L as shown,
and can be located, fastened, and machined in a very rapid man-
ner, as a turn of the thumb-nuts J J" releases the clamps, which
are raised above the work by the springs E E, and the work
can be slipped out and another gear located and fastened in its
place in very short order. The hole is bored in these gears, and
the hub faced by means of a tool similar to the one shown in Fig.
177. After boring the hole, it is finished to size by the usual
chucking-reamer and finishing "floating" reamer, which insures
the hole being round and true.
DETAIL SKETCHES OF TOOLS AND FIXTUEES FOR
MACHINING PULLEYS.
The set of tools of which sketches are here shown were de-
signed by the author for finishing countershaft clutch-pulleys in
the turret-lathe, and have been very successfully used for this
purpose. It was desired to turn out the pulleys in large quan-
tities, and to have the work accurately done, making them dupli-
cates so far as their finished dimensions were concerned. The
INTERCHANGEABLE MANTJFACTVRING.
173
tools were so constructed that the pulleys could, be finished com-
plete at one setting.
The type of pulleys which this particular set of tools was de-
signed to machine is shown in the two views in Fig. 179, and
consists of a six-arm pulley of a common type. The points to
be machined are as follows: The hole was to be bored and
reamed and one end of the hub faced ; the sides of the rim were
to be faced, and an interior portion of the rim bored and finished
Fir. 17
on a very slight taper, as shown, for the friction or rubbing sur-
face of the chuck ; and, finally, the face of the pulley had to be
crowned and finished.
In order to accomplish all these operations at one handling
of the piece, all the tools had to be specially constructed for the
purpose. They consisted of a chuck for holding the work
while being machined, a combination and boring hub-facing
tool, a turret fixture for boring and finishing the clutch portion,
and a special compound slide-rest, with cutting-tools at the back
and front.
174:
TOOL-MAKING AND
Two views of the chuck are shown in Figs. 180 and 184, and
the several parts of the chuck appear in detail in the other fig-
ures. The chuck so holds the work that all points to be ma-
FIG. 180.
chined are easily accessible to the cutting-tools. There are nine-
teen parts in the chuck. The body is a forging of mild steel,
i l I
Fig. 181.'
and is bored and threaded at the back to fit the spindle of the
turret-lathe. There are three projecting lugs or false jaws II I,
as shown, and the faces of these were turned off to form three
INTERCHANGEABLE MANUFACTURING. 175
even supports for three of the pulley arms. The outside sur-
faces K K of the lugs were turned to a suitable diameter for the
o
FIG. 182.
FIG. 183.
Fig. 184.
purpose of locating the pulley in a central position by means of
the inside of the pulley rim, which comes in contact with these
Fig. 185.
SCREW PLATE
Fig. 186.
JAW OF CHUCK
ll
I! 1
. '
V
r i
V-
1
,1
III
i
1 '•
1 i
n
w
iw
i.. I. r
i 1
ii |'i
1
1
!l li
ll
Fig. 187.
Fig. 188.
surfaces K K when the pulley is held in the chuck. The sur-
faces K and I of each lug, therefore, determine the position of
176
TOOL-MAKING AND
the pulley with sufficient accuracy for machining while the arms
are clamped securely by the jaws 0.
The construction and operation of the chuck will be clearly
understood from the engravings, and it will be seen that the pul-
ieys can be clamped in position or removed very readily. The
three jaws OOO which grip the spokes of the pulley and draw
them against the faces of the false jaws, are moved in or out, as
required, by simply tightening or loosening the wedge-screw P,
which raises or lowers the wedges N, as shown in the sectional
view of Fig. 184. In making the chuck it is interesting to note
that the finishing of the rectangular holes L and 31, Fig. 181, in
Fig. 189.
which slide the wedges iVand jaws 0, was accomplished by the
use of broaches of the type shown in Fig. 188. For such work
the broach should be constructed with very coarse teeth on the
lower end to take out the bulk of the stock. It will be noticed
that the teeth on the two ends of the broach are so inclined as to
give shearing cuts in opposite directions, the object of this being
to break off the chips as the broach passes through the work.
The upper end of the broach is left perfectly straight for about
two inches and serves as a "sizer." The broaching of the holes
is accomplished by forcing the broach completely through them
under the power-press. The machining of the other parts of the
chuck presents no difficulties and will be understood by reference
to the figures. All parts except the body of the chuck are of
tool steel, and all wearing surfaces were hardened and tempered.
The combination boring and hub-facing tool-holder is shown
in Fig. 189. After the hole in the pulley is bored and the hub
faced by this tool, it is finished by the small chucking reamer
and by a finishing reamer of the " floating " type, to insure the
hole being true and round.
INTERCHANGEABLE MANTJFA CTUEING.
177
The special turret-tool for finishing the clutch portion of the
pulley is shown in Fig. 190, and details of the parts in Figs. 191,
192, and 193. The three cutting-tools are held in dovetailed
channels finished to an angle of three degrees with the centre
line of the fixture, this being the angle of the chuck surface on
the interior of the pulley rim. Having the grooves finished at
Fig. 190.
this angle makes it easier to set the cutters correctly, and as the
cutters are held by clamping they can be adjusted to remove the
right amount of metal.
In Fig. 194 is a plan view of the special compound slide-rest,
with the cutting-tools in position. This slide-rest consists of the
main casting A, which is fitted to the carriage of the turret-lathe,
replacing the cross-slide; of the compound rest B and O, in
which the gashing- or roughing-tools are held ; and of the face
crowning- and finishing-tool fastened within the main casting A
Fig. 191.
in a dovetailed groove at the back, as clearly indicated in Fig.
195. There are seven roughing-tools and two side tools, located
in channels in the slide G and fastened by the set-screw in the
strap D — the six short ones for gashing the scale and roughing
off the face, and the other two for facing the sides of the pulley
rim. The face crowning- and finishing-tool is located in such a
178
TOOL-MAKING AND
position in the body plate A that its cutting -edge will operate in
a line tangent to the periphery of the pulley ; and as the tool is
designed to make a shearing cut, the metal is removed progres-
sively from one side of the pulley to the other, thus reducing the
Fig. 192.
Fig. 193.
strain and the tendency to chatter. A plan of the slide-rest is
given in Fig. 194, and in Fig. 195 is the elevation, which also
shows the manner of holding the pulley in the chuck.
Eeferring to Fig. 195, it will be seen that the pulley is se-
cured in the chuck by slipping the spokes into the notches of the
Fig. 194.
jaws and tightening the wedge-screws P so as to draw the spokes
tightly against the locating-faces, as shown. The hole in the
pulley is then bored and the hub faced by the combination tool
shown in Fig. 189, after which the clutch portion is finished by
the fixture shown in Fig. 190, the leading stud supporting the
work while it is being machined, and remaining in the hole until
the pulley has been finished. The face gashing- or roughing-
moving all that is necessary to clean them up.
INTERCHANGEABLE MANUFA CTUBING.
179
To crown and finish the pulley, the whole slide-rest is fed
out by the cross-feed screw of the carriage until the entire cut-
ting-edge of the crowning- and finishing-tool has passed beneath
Fig. 195.
it and finished and sized it to the shape and size required. The
use of this set of tools insures an exact duplication of the work
produced at a low cost.
There is one thing that must not be lost sight of, when con-
structing a forming- and finishing-tool of the type shown here,
Fig. 196.
for crowning the pulley : As the face or cutting-edge is finished
and ground so as to take a shearing cut, and the tool is located in
such a position in the main casting as to give it the required
clearance-angle, the forming-face must be finished as shown at
B, Fig. 196. As the tool is set at an angle with the face of the
pulley, in order to produce the shape desired, one side must be
considerably higher than the other, as at B. This should be
figured out and a templet made, according to the degree of clear-
ance given and the amount of shear to the cutting-face.
180
TOOL-MAKING AND
TOOLS FOR MACHINING A SPECIAL CASTING.
The hood-shaped casting shown in Fig. 197 formed part of
an electrical appliance which was being manufactured in large
numbers and, as it is a characteristic piece of duplicate work,
FIG. 197.
the method employed in its production may prove of interest to
my readers.
The operations necessary for machining this casting were,
first, to drill and ream the ^--inch hole A; second, face the base
B ; third, finish the circular portion C C given diameter and
Fig. 198.
taper ; and, finally, to drill the ^-inch holes through the centre of
each of the four parts D. The first and second operations were
both performed in a turret-lathe with the casting held in a four-
jaw chuck, as shown in Fig. 198. The hole A was first bored
INTERCHANGEABLE 2IANUFA CTTJRING.
181
with the usual turret boring-tool and reamed to size with a
''floating " reamer. The work was then driven slowly, by throw-
ing in the back gears ; and the second operation, that of facing
the base B was performed by the use of a large face milling-cut-
ter, placed on an arbor which was held in the turret-head, as
shown in Fig. 198. This cutter was of the ordinary type of
facing -cutter, except that the teeth, on the facing side, were
staggered to prevent chatter. The cutter, which was driven by
the key K was held in place on the arbor by the nnt N and
washer W.
With this cutter it was possible to machine a large number of
castings before it required to be ground.
The third operation, that of finishing the circular taper sur-
faces G G, was accomplished as shown in Fig. 199 by the use of
Fro. 199.
an end-mill in a universal milling-machine. The work was held
on an arbor between the tail and dividing-head centres and the
swivel carriage moved around until the table and arbor stood at
the desired angle with the face of the milling-cutter. After set-
ting the work so that the desired amount of stock would be re-
moved, the cross- feed screw was clamped, and the work fed
against the cutter by revolving the dividing-head by hand. For
the last operation, that of drilling the holes D D, the jig shown
in Fig. 200 was constructed. This jig was made in two parts, a
182
TOOL-MAKING AND
body casting in which the work was located, and a lid W, which
was hinged at one side and carried the four tool-steel bushings
B B by means of which the holes were located and drilled.
A hinged bolt and thumb -nut Q served to clamp the two
parts together when the jig was in use.
The bottom of the body was bored out to correspond in taper
and diameter with the taper surfaces of the work at C C. Ex-
tending inward from one side of this hole was a lug K in which
was fitted the stop -pin Z. The stem of this pin, where it fitted
FIG, 200.
the stop-lug, was eccentric with the body of the pin, so as to pro-
vide for adjustment, while the screw J locked the pin in p]ace
when the proper adjustment was attained.
This pin was brought against one of the inner lugs of the
castings, as at E, and thus located the lugs in the proper position
to be drilled.
When in use the swinging clamp Q is released and the lid W
thrown back. The work is then slipped into the body and lo-
cated within the taper seat and against the stop -pin Z. The
lid is then brought down by grasping the handle 8 and as the
spring pad TJ strikes the work, the tension of the spring
enables it to force it tightly down on the locatlng-seat. The lid
is then held down on the body casting with one hand, while the
swinging clamp is swung up and fastened with the other. The
casting is then drilled through the bashings B B. One of the
best features of the jig is the impossibility of the chips and dirt
interfering with the accurate and positive locating of the work.
INTERCHANGEABLE MANTJFA CTUBING.
183
A MULTI-SPINDLE DRILLING AND TAPPING AT-
TACHMENT AND WORK FIXTURE.
The special multi-spindle drilling and tapping attachment
and its work fixture, shown in the accompanying illustrations,
were designed by the writer. The work shown in Fig. 201 is a
circular casting with a large central hole and six small holes a a.
It was for drilling and tapping these six holes that the attach -
FIG. 201.
ment here shown was designed, and as it proved a great cost-re-
ducer and allowed the required degree of interchangeability at
the minimum of cost, its adaptability for a large variety of work
is apparent. It also shows another use to which the ever handy
— and often idle — turret-lathe may be put.
The six holes for the casting are equally divided around a
circle concentric with the large hole c c, and are drilled entirely
through the bosses. The large hole is bored and one side of the
bosses faced in a preceding operation in the turret-lathe, and
the keyway is let in so as to be in the same relative position to
the bosses in all of the castings.
Fig. 202 shows, partly in section, the fixture complete and
also several of the main parts. Fig. 203 is a plan, with the
184
TOOL-MAKING AND
arrangement of the gears and their relative positions on the sta-
tionary spindle-disk. As shown in Fig. 202, the attachment
consists of three main parts, of which A is the driver, C the sta-
tionary spindle and leading stud. The driver A, of cast-iron,
was finished first, boring it out at the back and then threading
it to fit snugly the spindle of the turret-lathe. A hole was then
bored straight through from the face at B and threaded as
FIG. 202.
shown, getting it dead true. The front was then faced, thus
insuring the lubrication of the entire surface.
The stationary disk C, a circular casting with bosses on each
side, to the number of thirteen on the front and seven on the
back, was then machined. The central hole for the spindle D
was first bored and reamed to size, a mandrel was driven in, and
both sides were faced, leaving all the bosses the same height.
We were now ready to locate and finish the holes for the six
spindle-gears H and the intermediate gears K. A stud of tool
steel was turned up, hardened and ground to fit the central hole
in the disk tightly. We then finished up six buttons of the type
INTERCHANGEABLE MANUFACTURING.
185
used for accurate jig-making, aucl ground them to ■g-'-inch. on the
outside and the ends perfectly square. The central stud was
entered into the hole and one of the buttons was located the
exact distance from the centre by using the verniers and deduct-
ing the diameter of the stud and button. The button was then
fastened to the disk by its screw, being located as. nearly in the
centre of the bosses as possible. The second button was located
the required distance from the first and from the centre of the
stud in the same manner, and this operation was repeated until
all sis buttons were located.
The disk was clamped on the lathe face-plate and the central
stud removed. The first button was trued and removed, and a
FIG. 203.
£-inch hole drilled, bored, and reamed entirely through the disk.
The next button was then located, trued, and removed and the
hole bored and finished in the same manner ; repeating until the
six holes were finished. We were now sure of the accuracy and
position of the gears when placed, and the interchangeability of
the holes when drilled. Before drilling and tapping the holes
for the six intermediate gears, the gears were turned and cut.
The drill-chuck spindles and gears were each in one piece and
were mild-steel forgings which were first centred and faced the
same length. The spindle portions G were turned to within
.005-inch of the finish size and the ends threaded for the nut,
186
TOOL-MAKING AND
leaving a shoulder for the washer. The taper portion for the
chuck was turned, leaving the same amount of stock for finish-
ing as on the other end. The gear portion J? was then finished
to the required diameter, and all were finished in the grinder,
with the portion G a smooth running fit in the reamed holes in
the disk, and the sides of the gears ground perfectly flat and true
with the spindles. The teeth were then cut.
The six intermediate gears K also were of steel; and six
shoulder-studs or screws were made of tool -steel for them. The
Fig. 204.
large, or driving-gear F was of cast-iron and was bored and
reamed to the same size as the central hole in the disk ; the sides
were ground as the others, and a keyway let in for fastening it
to the spindle and leading stud D. The portion D of the stud
turned within the disk after hardening. A second shoulder was
left at M so that the space between it and the first would accom-
modate the disk and the driving gear. A hexagon was milled
INTERCHANGEABLE MANUFA CTURING.
187
at M and the stud reduced for the remainder of its leugth, the
eud rounded to act as a leading stud and enter a reamed hole in
the work fixture when in operation, to support it. The six holes
for the intermediate-gear screws were then drilled and tapped,
so that the gears would occupy the positions shown in the plan.
After drilling and tapping the hole for the stud B B all parts
were assembled, as shown, the chucks being driven tightly on to
the spindles.
The fixture for locating and fastening the work is shown in
Fig. 204. The body casting is machined first. After being cen-
tred it has the stem turned to fit the hole in the turret-head. It is
Fig. 205.
then reversed and held by the finished stem in a nose-chuck and
the front is finished, first taking a cut off the two projecting
bosses G G, then finishing the seat for the work and turning the
hub D to fit nicely the large central hole in the work (under
cutting it at the back to prevent dirt or chips from accumulat-
ing), and, lastly, boring and reaming the centre hole E for the
leading stud of the drilling and tapping attachment. Before
locating and letting in the key F in the hub D the lid was fin-
ished and fastened to the body casting and the holes for the drill -
bushings were let in.
This lid-casting is circular, with a large hole L in the cen-
tre and raised bosses at the opposite sides where it is hinged and
located to the body casting. These bosses were faced and a cut
was taken off one side of the casting for the bushing-heads to
188 TOOL-MAKING AND
locate. The lid and the body casting were then clamped to-
gether so that the boss faces rested true with each other, and the
hole for the hinge-screw H was let in, tapping it in the body
casting and enlarging and reaming it to a snug fit for the large
portion of the screw in the lid. The screw H was then let in
and the hole I drilled aud reamed for the taper locating-stud J.
We were now ready to locate and finish the bashing-holes. The
taper locating-pin J was forced in tightly and a hardened and
ground plug was finished to fit tightly the hole E. Then by
using the buttons used for locating the spindle holes in the
drilling and tapping attachment these six holes were located in
the same manner. The hinge-screw H and the locating-stud J
were then removed, the lid was clamped to the face-plate, the
buttons made true, and holes bored aud reamed to the required
size. The bushings K were made of tool steel and forced into the
holes in the lid. Three holes were then drilled and tapped in
the body casting in the positions shown by the dotted lines in
Fig. 204 to accommodate the clamp -screws. These three clamps
are only used when tapping the holes, the lid being then
removed. After the six clearance-holes for the drills and taps
Mere drilled and the key let in so that the bosses of the casting-
would cam approximately correct, the fixture was complete.
In Fig. 205 is shown the manner of setting up the multi -spin-
dle attachment and the work fixture. The driver, or back plate
of the attachment is screwed on to the spindle of the turret-lathe.
A clamp -strap of finch thick flat iron, bent to the shape
required, with a hole in the centre for the stud B B, Fig. 213,
and the ends bent inward and set-screws let in, was then secured
with the ends fastened to the body of the lathe and the stud
B B fastened to the strap by the nut, thereby locating and fast-
ening the spindle-disk without the possibility of shifting when
in operation.
The work fixture was located by entering the stem into one of
the holes in the turret-head, the slide moved up, and the fixture
manipulated until all six drills entered the bushings of the fixt-
ure. The fixture was then fastened, the lid was thrown back,
the work or casting to be drilled located by the key on the hub
of the fixture, as shown, and the lid or bushing-plate relocated
INTERCHANGEABLE MANUFACTURING. 189
by the taper plug. The lathe is started, and as the driver
revolves, and with it the driving gear, the spindle-disk remains
stationary, allowing the six drills to turn at the speed desired.
The turret-slide is moved up, the six holes are drilled in the
work, the finished piece removed and replaced by another, and
the operation repeated. After all the castings in the lot have
been drilled they are tapped by simply substituting taps for the
six drills and removing the bushing-plate from the work fixture.
The locating of the castings so that alignment of the drilled holes
with the taps will be perfect is accomplished without any trouble,
as the keyway in the casting brings them in the same location
as in the first or drilling operation, and the three clamps hold it
tightly in position. When tapping, the spindles are run at the
proper speed and the work is brought up to the taps, the opera-
tor keeping his hand on the shifter, and as soon as the taps have
come through the holes the lathe is reversed and the taps are fed
out.
CHAPTER XIII.
Special Tools, Fixtures, and Devices for Machining
Repetition Parts in the Screw-Machine.
FOUR SPECIAL BOX-TOOLS FOR THE SCREW-
MACHINE.
The tools shown and described in this chapter were designed
for and used in the screw-machines, but many of the designs are
adaptable with slight modifications to the turret-lathe as well.
The tools shown in Figs. 206 to 209 are for making small tubes
used for perforating leather shoe-tips. These tubes run from
tV t° i-inch in diameter, are made from drill rod, and are re-
FIG. 206.
quired to be finished with a smooth reamed hole through them
true with the outside, and with one end chamfered to a sharp
edge. In producing the larger sizes of tubes very little trouble
was encountered, but for the smaller sizes (and they were required
in the largest quantities) much trouble was met with. All trou-
ble, however, was overcome and very good results attained by
the use of the tools shown herein.
Fig. 206 is for chamfesing the ends and centring the tubes.
The body or box portion, of cast-iron, has a hole through it for
190
INTERCHANGEABLE MANUFA GTUBING.
191
the entering-tool JPand its adjusting-screw C. A hole is broached
through the body for the chamferiug-tool C, at au angle which
allows the face of C to be ground square. The bushing G is of
tool steel, is hardened and lapped to the size of the drill-rod.
Fig. 207.
By chamfering the end of the tubes with this tool, before drill-
ing and reaming the hole, a sharp edge can be produced.
Fig. 207 shows the tool for drilling the tubes. The drill is
held in a split bushing by the adjusting-screw K and round-
head screw N. The bushing L is forced into the holder.
Fig. 208 is for cutting off the tubes. On account of their
smaller diameter it is necessary to support the stock during the
operation. The body of the tool is of cast-iron. The cuttlng-
off tool is of a somewhat special construction. It is of a ^ x ■£--
inch stock finished all over to fit within the channel, and with a
Fig.
groove in one side for the feather U. The grooves Ton the bot-
tom are for the collar of the feed-screw W. The cutting end of
the tool T is finished to the usual shape required for such a tool ;
as narrow as possible, accordiug to the size of the stock. These
three tools produce the perforating tubes to the degree of inter-
changeability and accuracy required, and in a very rapid man-
192
TOOL-MAKING AND
ner. The tubes, after being thus finished, are hardened and
tempered to a dark blue, and are forced into radial holes in a
mild-steel disk. Different combinations of sizes of tubes are
located in these disks, to produce the pattern desired in their
leather shoe-tips and miscellaneous leather findings.
The box-tool, Fig. 209, is of a distinctly different type from
those above described ; it is used for pointing slender needle valves
on an incandescent oil-lamp of well-known make. It is rather dif-
ficult to point wire of small diameter by the ordinary means avail-
able in the screw -machine, especially if the points are to taper
Fig. 209.
quite gradually, as at M. By the ordinary method the cutting
surface of the tool would be so wide that it would be almost
impossible to keep the wire true and hold it sufficiently rigid.
The body or box portion of the tool is a forging of mild steel,
with a rectangular hole at B and a tool -steel bushing at C. The
cutting-tool E is fitted snugly into a square broached hole, the
side of which is in line with the end of the bushing. The rear
end of the tool is threaded for adjustment nut O. A bracket is
fastened to the body of the tool, and the spiral spring, which is
required to be quite stiff, is located as shown. A hole is let into
the body at D as clearance for the angular-faced tool-post fixt-
INTERCHANGEABLE MANUFACTURING.
193
ure L. A channel F is let into the under side of the pointing-
tool E, with a taper side at the rear coinciding with the taper
of L. In first operation the cutting tool E is allowed to pro-
ject, adjusting it by the nut G slightly beyond the centre bush-
ing C. As the box-tool is brought up to the work, the wire
enters the hole D. As the tool E begins to cut, the engager L
commences to force the tool back, and continues to do so until it
ceases to cut and the wire is pointed as shown. The turret is
then brought back, and the spring causes the cutting-tool to
resume its former position.
SCBEW-MACHINE FIXTUBES AND TOOLS FOE
MAKING SPEED-ENDICATOBS.
The sketches herewith are of two special chucks and of a
tapping-machine which were designed by Mr. W. J. Parker,
foreman of the Fulton Machine Works, Broooklyn, the chucks
being used for machining a casting (Fig. 210) which forms the
body of a speed-indicator manufactured by that firm. The work
on this casting was the boring out of the large circular portion
A for the revolving dial-plates of the
indicator ; the facing of the bottom B
and of the hub around which the dials
revolve, and the drilling of the small
hole C in the centre of this hub. All
this was accomplished in one opera-
tion, after the work had been fastened
in the chuck (Fig. 211). The second
operation was the boring and reaming
of a hole D (Fig. 210) for the spin-
dle of the indicator and the finishing of a centre and thrust
bearing for the end of it at E. Both chucks are used in the
screw-machine in conjunction with a set of turret-tools for each.
Fig. 21k shows the chuck used for the first operation. It
consists of a circular casting having a hub at the back and a
raised portion on its face for holding the work. The casting is
fitted to the screw-machine spindle, and faced and bored to admit
the large circular portion of the work as shown at L, being bored
13
194
TOOL-MAKING AND
to a depth sufficient for the upper side of the work to project
slightly above the face H of the chuck. The face of the chuck
is milled away on each side of the square central portion H so
that the work may be easily located or removed. J" is a flat
Fig. 211.
machine-steel plate, located on the face of the chucks by two
dowel-pins K K and fastened by the four corner screws L L L L.
This plate, while fastened to the main casting, is bored suffi-
ciently to tightly clamp the edges of the large circular portion
and for clearance for the cutting-tools. Fig. 211 shows clearly
VERTICAL CROSS-SECTION OF
CHUCK AND WORK
Fig. 312.
how the work is located and clamped on the chuck. The work
is machined by the usual type of turret-tools.
The second operation is accomplished by the use of the chuck
shown in Fig 212, which is of distinctly different design from
that of the chuck Fig. 211. It is a circular hub-backed casting,
INTERCHANGEABLE MANUFACTURING. 195
with a rather long, flat, projecting standard at II, fitted, as in
the other case, to the screw-machine spindle and having the face
of H machined flat and square with the face of F. The work is
located on this projecting face at two points by K and J; also
at I by a circular machine-steel disk fitting within the portion A,
Fig. 210, of the work and fastened to the face H, Fig. 213, of
Fig. 213.
FIG. 214.
the chuck by screws and dowel-pins (not shown) and at K by
the steel plate J, which, as will be seen, is fastened by screws
and dowel-pins. For clamping the work to the chuck the
swinging bracket and clamping-screw N are used, the construc-
tion of which is shown in the cross-section view of Fig. 214,,
where the work is shown fastened upon the chuck. The work
machined in these chucks is, needless to say, perfectly inter-
changeable.
METHOD FOE FINISHING DUPLICATE WOEK IK
THE SCEEW-MACHINE.
The special tools and fixtures here described were designed
for the screw-machine, and consisted of an improved driver
for the work ; a special arrangement of lathe centres, and a form-
ing-tool and holder which will duplicate work without chatter-
ing and without regard to pressure applied by the operator.
The particular piece of work for which these tools were de-
signed is shown in two views in Figs. 215 and 216 and is called
a "goose-neck." It is a brass casting, and is finished at the
196
TOOL-MAKING AND
taper end marked A. Before finishing this surface, the castings
were centred at C, and chamfered slightly on the inside at B.
The first fixture made for the finishing operation was the special
B B
Fig. 215.
Fig. 216.
chuck, a cross-section of which is shown in Fig. 217. The body
of the chuck was a casting of the shape shown, and was bored
out at C C. It was first chucked in the lathe and bored out and
threaded at G G to fit the spindle of the screw-machine, and then
Fig. 217.
squared up. It was then faced and the rim trued. A hole was
bored and threaded at D to admit the centre E, which was fin-
ished with a shoulder at jP so as to allow it to rest squarely
INTERCHANGEABLE MANUFA CT UE1NG.
197
against the face of the chuck. A square hole was then let
through the face of the chuck to admit the driver I, which was
made of f -iuch round tool steel and bent as shown, and the end I
finished to a smooth fit within -the hole J. The round portion R
of this driver was long enough to allow it to extend clear through
the screw-machine spindle, and was connected to the wire-feed
lever. This manner of connecting the driver allowed it to be
forced out and in, thereby permitting the work to be located on
the centres, and removed when finished without stopping the
machine.
As the edge B of the work, Fig. 215, gives a very narrow bear-
ing for the tail -centres, and as the work revolved very fast, it
FIG. 218.
was not practical to adopt the ordinary centre, as there was a
tendency for the end of the work to run hot and burr up. So, to
overcome this, the special sleeve and running-centre, shown in a
cross-sectional view in Fig. 218, were made. This fixture consists
of a sleeve which was first bored out and tapped at the back end
for the centre end-thrust screw M. It was then placed on an
arbor and turned taper on the outside to fit the tail -stock, which
had been fitted to the screw-machine. The end-thrust screw M
was then made with thrust end finished flat, hardened and pol-
198
TOOL-MAKING AND
islied. It was then screwed tightly into the sleeve. The run-
ning-centre K was then made of tool steel and finished to fit the
sleeve smoothly, and tapered at L and the point rounded. This
end was then hardened and polished. After an oil-hole had
been let into the sleeve and the inside polished smooth, the fixt-
ure was finished.
As the manner of finishing the formed surface of the work is
Fig. 219.
distinctly different from tne usual methods in general use, and
as the forming-tool and holder are of a novel design, they are
worthy of a detailed description.
By referring to Figs. 219 and 220, in which a plan and side
view respectively of the tool and holder are shown, the following
P^O
vl
k(St
p
~~" i
Ms
\ SIDE VIEW
FIG. 220.
description of them will be intelligently understood. The holder
is a casting of the shape shown at F, and was dovetailed on the
bottom and fitted to the cross-slide of the screw-machine and
equipped with a rack to mesh with the feed-gear, as shown at
N, Fig. 218. The portion for holding the forming-tool Q, Fig.
INTERCHANGEABLE MANUFACTURING . 199
219, was then planed dovetail, slanting - upward to the degree
shown in the side view of Fig. 220. A hole was then drilled
and tapped through the lug B to admit the tool adjusting-screw
8. Two headless set-screws T T were also let into the side, as
shown. The forming-tool Q was of f -inch flat tool steel, finished
all over, and fitted to the holder as shown. The shape required
was then worked out on the face for its entire length, and finished
in the milling-machine with a special fly-cutter, as shown in Fig.
218. The cutting-face of the tool, V V, Fig. 219, was sheared
off to the angle shown, so as to allow the work to be cut gradu-
ally. The tool was then hardened and drawn to a light-straw
temper, and the cutting-face ground and oil-stoned to a keen
edge. The fixture and tools were now complete and ready for
work.
The parts were set up in the screw -machine in the relative
positions shown in Fig. 218. The machine was started, and the
driver-lever pulled back, thereby drawing the driver I into the
chuck. The work was then placed on the centres, with the por-
tion C on the chuck-centres and the face end on the running-cen-
tre K. The driver-lever was then pulled out, causing the driver
1 to emerge and drive the work, the running-centre L travelling
with it. The handle O of the cross-slide was then pulled down
and the forming-tool presented to the work, cutting the face
gradually. And as each portion of the work was reduced and
finished, that point of the tool passed the centre and came out
under the work; and as the whole face was finished, the entire
cutting-face of the tool passed free and clear of the work. The
driver I was then drawn in (without stopping the machine) and
the tail-centre drawn back and the work removed. Another cast-
ing was then located ou the centres, the driver sent out, and the
work finished as before.
As will at once be seen, the use of the special chuck reduces
the time necessary to locate the work on the centres, and remove
it when finished, to the minimum. And the running tail-centre
eliminates the possibility of the work running hot and burring,
as well as the waste of time in adjusting the centre against the
work. The methods of finishing formed surfaces by means of
tools of the design shown is meeting with more favor all the
200
TOOL-MAKING AND
time, as very wide and intricate forms can be duplicated on
round work without any trouble. Another thing, by the use of
this tool work can be finished, one piece in exact duplication of
the other.
FIXTUEES FOE FOEMIKG PIECES OF IBEEGULAE
OUTLINE.
In the preceding chapter a fixture for forming pieces of ir-
regular outline from the bar was described, which fixture was
adapted to work having considerable stock to be removed. The
tool here to be described consists of a similar fixture for use in
the screw-machine for forming irregularly shaped surfaces, but
from individual castings instead of from the bar, and in which
less metal is to be removed.
The article for which this device was used is an improved gas-
stove cock made in two parts, each of which is of irregular exte-
rior outline, as shown in the longitudinal sectional view in Fig.
Fig. 221.
221. The length of the assembled cock over all is 4f inches,
and the pieces are composition castings with the holes K and F
cored in them. Certain preliminary minor operations are neces-
sary on both parts 1 and 2 before the forming -cutter is used, in
order to form the threaded hub G on part 1 and the threaded
recess B B in part 2 for a means of definitely locating them on
the face-plate, which operations will be described later on.
The forming-cutter used for obtaining the irregular outline
surface is one of the circular forming type of cutters, which is
shaped entirely around its exterior surface, the cutting-edge
being produced by milling out a longitudinal groove on its exte-
rior as shown in Figs. 222 and 228. This is the type of cutter
that may be ground and reground almost indefinitely without al-
INTERCHANGEABLE MANVFA CT UBING.
201
tering the shape of its cutting -edge if the body of the cutter is
properly shaped. The cutter shown in Figs. 222 and 223, which
represent the cutter used for machining the surface of part 2 of
the gas-cock, was made of tool steel, which was annealed and
bored out at D and a keyway let down through the entire length
at C, after which it was driven on to an arbor and the ends fin-
ished as shown at B B, and the required shape turned on to the
outside from end to end to templet, as shown. The finishing of
Fig. 223.
this forming was done very carefully by first roughing it out with
the usual lathe-tools and then using a variety of hand-tools to
finish it to shape. Especial care was taken to get its entire sur
face smooth and free from marks, and it was finished to a dead-
202
TOOL-MAKING AND
smooth finish by means of lapping with stick, emery, and oil.
This was necessary, as the work was required to have a high fin-
ish after being machined, and as the manner in which the cutter
was presented to the work allowed of its burnishing the same as
soon as the cutting-edge had removed the required amount of
stock and passed the centre.
After being lapped, the cutter was set up in the milling-ma-
chine and a groove milled out to form the cutting-edge from E G
Fig. 224.
to F, as shown in Fig. 222, it being milled on a spiral, as shown
in the face view, Fig. 222, so as to cause the cutter to remove the
stock progressively. In fact, the cutting-edge of the cutter was
finished in the same manner as a wide-face milling-cutter, except
that the spiral was not quite as abrupt. After finishing the cut-
FIG. 225.
ting-edge as shown, the cutter was carefully hardened and drawn
to a very light-straw temper, thus leaving it as hard as is con-
sistent with reliable cutting.
The cutting-edge was then ground on the cutter-grinder, and
carefully oil-stoned so as to present a smooth, keen edge for its
entire length. The holder, or bracket, shown in Fig. 223, which
supports the cutter and its cutter-stud H, Fig. 225, was made
from a forging with the shank N finished to fit the large tool-post
of the turret-lathe. The way in which the cutter is mounted in
the holder is shown in Fig. 223, which shows a top view of the
INTERCHANGEABLE MANUFACTURING.
203
cutter in place upon its stud H and the hand-lever R mounted
upon the projecting end M of the stud.
The manner of using the fixture may be understood from Figs.
Fig. 226.
226 and 227 ; Fig. 226 showing a front view of both fixture and
work in position, the face-plate, the turret-head, and Fig. 227 an
FIG. 227.
end view toward the face-plate to indicate the manner in which the
cutting-edge of the cutter is presented to the work. In machin-
ing the work the handle of the cross-slide is moved by the left
204
TOOL-MAKING AND
hand of the operator until the cutting-edge of the tool is in the
position against the work shown in the end view, Fig. 227, and
held there with the help of the feed-screw of the cross-slide,
while w T ith the right the lever of the forming-tool is pulled for-
ward. As the cutter is slowly revolved in the holder by the
pressure on the lever, it cuts and removes the required amount
of stock progressively, due to its spiral cutting-edge, and as the
cutting-edge passes the centre line the friction of the finished por-
tions of the work revolving rapidly against the exterior of the
cutter produces a high finish of its entire surface.
The cutter which was used for milling part 1 of the gas-cock,
Fig. 221, is shown in front view and section in Figs. 228 and 229,
and in end view in Fig. 224. This
cutter was made, tempered and
CUTTER
Fig. 228.
ground exactly the same as was the other, and its method of
use in removing the stock and obtaining the burnish or polish is
identical.
In connection with the finishing of these gas-stove cocks other
Q\2T_~Z
Fig. 230.
fixtures were used which may be of interest. In forming the
threaded hub C 0, parti, Fig. 221, a pair of slip-jaws for a regu-
INTERCHANGEABLE MANUEA CTUBING.
205
lar two-jaw chuck was used for chucking the work while ma-
chining. These jaws, which are shown in Fig. 230, are of cast-
iron ; are finished dovetail to drive into the jaws proper of the
chuck, and are located in the proper relative positions by means
of a taper-pin at B. The way in which these jaw r s are con-
structed and finished to allow of locating the work as shown is
evident from the sketch. The facing
of the surface M M is accomplished by
means of a hollow mill, which differs
1 R?T
;__r" — i
Fig. 231.
FIG. 233.
from the type generally used in that it has fifteen teeth. The
hub G C is finished by the mill also, the thread being cut by
means of a collapsible die.
In Figs. 231 and 232 are shown the slip-jaw\s which are
used for the first and third operations on part 2, Fig. 221, which
FIG. 233.
contains the gas-cock proper. These two sets of jaws are con-
structed similar to the first set, Fig. 230, and are used in the
same way. The part shown at A, Fig. 232, is for holding the
casting for part 2 while the surface at A A is being faced, the
206
TOOL-MAKING AND
seat for the rubber washer let in at D D, and the hole at B bored
and tapped to fit the threaded hub, part 1. The other set of
jaws is used for holding part 2 after being machined all over,
when the taper hole for the key J is being let in at 8, Fig. 231,
which shows the work located within the jaws and the hole
fig. 334.
drilled at 8. This hole, after being centred in the usual man-
ner, is reamed to the required taper by means of a "floating"
reamer of the usual type.
For turning the washer-seat at D D, in part 2, the special ec-
centric box-tool shown in Fig. 233 was used, which is of an inter-
esting construction. J. is a holder or frame, made of cast-iron,
which a shank portion at jB turned to fit the hole in the turret.
C is an eccentric bushing located within the holder by the set-
screw H; G the cutting-tool ; F the lever by which it is manipu-
lated. The depth of cut is regulated by adjusting the lever stop-
INTERCHANGEABLE MANUFACTURING. 207
screw J, which is let into the projecting lug K as shown iu the
end view of the tool. In using this fixture, after the tool G has
beeu entered into the cored hole in the work the required dis-
tance, the lever _Fis raised slowly until it rests against the stop-
screw J, which determines the proper depth of cut, then it is
dropped and the tool backed out.
A novel drill-jig was designed for use in boring the six in-
clined air-draught holes leading into the combining-chamber F
in part 2 of the gas-cock. The jig is shown in plan and in
sectional elevation in Fig. 234, with the work in place. As is
shown, these six holes are required to be drilled at an angle with
the axis of the casting, and also to be equidistant, and an inter-
esting design is the result. A is the body casting of the jig,
which is machined on the base at D, and also on both sides of
the projection B, to an angle Y with the base, as shown. The
indexing-device X and the locating-stud for the work are of tool
steel, hardened and ground. There are six equally spaced
notches in the index-plate which coincide in shape with the end
H of the index-pin R and locate the work for the six different
holes. The drill-bushing Pis located as shown in the swing-lid
J, which is hinged within the two sides K K of the body casting
A by means of the pipe L. A hole in the lid allows clearance
for the work when located in the jig ; all that is necessary for
removal being to swing the bushing-lid J back and unscrew the
work off the locating-stud.
CHAPTER XIV.
The Construction and Use of Boring Fixtures and
Similar Tools.
THE DRILL-PRESS AND BOEING FIXTURES.
One of the things that make the large drill-press a valuable
machine tool is its adaptability for performing accurate opera-
tions in the production of interchangeable parts by the use of
simple and often inexpensive fixtures. In fact, I do not hesitate
to state that it runs the turret-lathe a close second for the place
of the most rapid and economical producer in the shop.
Now aside from the adaptability of the drill-press for jig-
drilling, there is any quantity and variety of work recpairing to
A a
Fig. 235.
be bored which can be handled to good advantage on this ma-
chine; and in this chapter, among other things, I will devote
considerable space to describing and illustrating types for bor-
ing-fixtures which were designed to be used on the drill-press
and have worked well in practice, and their presentation will
208
INTERCHANGEABLE MANUFA GTURING.
209
prove suggestive for others. The practical points for the design-
ing and construction of the fixtures will assist the tool -maker in
the attainment of the desired results with ease, and dispense
with much unnecessary labor and expense.
BOEING AND FACING FIXTURE FOR "SEXTIT"
CASTINGS.
The casting shown in sketch Fig. 235 has six radiating cylin-
ders, each with a cored hole through it. It was necessary to
bore and finish the holes in line with the central hole E, and the
F a. 236.
opposite holes in line with each other. The jig shown in Figs.
236, 237, and 238 was made for the job.
The centre hole was first bored and counterbored, and the
front faced at D. It was then driven on to an arbor and the
back faced at F.
The jig consists of an angle casting with a boss, faced on the
back at H and I respectively, also a back extension on the top.
After being planed on the bottom and dovetailed for the bush-
ing-plate K, bosses H and L were faced and the top was planed
and dovetailed for the upper bushing -plate J. It was also dove-
tailed on the side for the index-pin bracket W, and the hole
bored for the clamping- stud 0.
The two bushing-plates K and J, of machine steel, were fitted
tightly into the dovetailed channels, located in line with each
14
210
TOOL-MAKING AND
other, and fastened. The centres of the holes for the bushings
U and V were located by setting the casting on its side on a sur-
face-plate and striking a line from the centre of the hole for
the stud to the plate J and K with the help of a Brown &
Sharpe height-gauge. The centre in the opposite direction, the
distance from the face of the boss H to the centre of the bushings
TJ and V was also marked. The plates J and K were then
FIG. 237.
driven out and the holes were bored and the two bushings U and
V were made and forced in. The plates were then returned to
their respective positions.
The index-plate N and clamping-stud are in one piece. It
was a mild -steel forging. The plate had on its periphery six
equidistant square notches. The index-pin bracket W, a cast-
ing, was then fitted to drive tightly into the dovetailed channel
in the side of the angle-plate. The hole for pin X was then
bored.
The pin was made of tool steel, the end fitting the square
notches in the index-plate, and slightly rounded to enter .the
notches easily. A stiff helical spring V was made and also a
INTERCHANGEABLE MANUFACTURING. 211
hole was drilled in the pin X for the spring cross-pin. After
the handle Z was made all the parts were assembled.
All that remained to complete the rig was the boring-bar, Fig.
Fig. 233.
5:
239, and the two sets of cutters B B and I). This bar
was of machine steel, turned taper at the end to fit the
drill-press spindle, and for the rest of the length a run-
ning fit in the bushings U and V. The bar was small
enough to clear the cored holes. Two sets of cutters
were made, one set for roughing and the other for finish-
ing. These cutters were fastened in the bar by taper-
keys. The jig was strapped to the table of a large
drill-press. The index-plate N, with the pin X in one
of the notches, was clamped and a casting to be bored
clamped in position ou it, so that the boring-bar would
be as nearly central as possible in the cylinder to be
bored. The roughing -cutters were then fastened in the
bar and the holes were bored. These cntters were then
removed and the finishing pair were substituted and the
holes were finished.
After all six holes were bored, which required only three ad-
justments of the index-plate, both ends of all six cylinders were
faced by using the cutters D. All the eastings, of which there
::1
:9
Fig. 239.
212
TOOL-MAKING AND
were a large number, were bored and faced in this manner, and
were found, when assembled with other parts, to interchange per-
fectly.
DEILL-PEESS BORING
EIG FOE INTERCHANGEABLE
WOEK.
The tools described in the following were used for boring and
finishing the cast-iron shell shown at B, Figs. 242-243. The part
finished is shown at F, being a seat for a brass ring that was to
fit in snugly so as to be air-tight, and it was also necessary to
have them all exactly the same size. The shells were being made
in lots of five hundred.
The jig for holding the shells is also shown in the two views.
A is the jig, of cast-iron, which was faced off on the bottom and
Fig. 240.
Fig. 241.
strapped true on the face-plate of the lathe by the ears E E. It
was then bored out to the shape and size of the shells at G and a
hole bored in the bottom for the plug I). It was then milled out
at three places on the top to give the three wings D clearance.
The plug D, made of machine steel, was then turned and finished
so as to just fit the inside of the shells, as shown, and then driven
into the jig A, projecting through at the bottom, as shown. The
part projecting through just fitted the centre hole in the table of
the large drill-press in which the boring was done.
Figs. 240 and 241 show the holder and tools for boring, which
were made in the following manner: G is the holder proper,
made of cast-iron with three wings, to allow of using three cut-
INTERCHANGEABLE MANUFACTURING.
213
ting-tools, as we found after experiment that this number worked
the best. The tool was first chucked and the hole I bored and
reamed for the shank J. It was then removed and the shank J
turned and finished to fit the spindle of the drill-press, with a
shoulder at M. The other end was turned down so as to drive
Fig. 342.
snugly into the holder G. The assembled tool was then put be-
tween centres in the milling-machine and the holes for the tools
K K JSTwere laid out and drilled and reamed. It was then taken
out and the holes for the set-screws L L L were drilled and
Fig. 243.
tapped. Next, the three cutting-tools were made and finished as
shown. These were hardened and drawn, and inserted in their
places, which completed the boring-tool.
A piece of steel the size of the hole in the table was chucked
in the drill-press and inserted in the hole in the table, which was
214 TOOL-MAKING AND
locked, thereby setting it true with the spindle. The jig A was
strapped on the table by the ears E E, with the lug D in the
centre hole, and the work put in, resting on the bottom as shown
in the sketch. The plug D centred it and the three pins not
shown entered the holes in the ears B, which prevented it from
truing. The holder, Fig. 240 was then set into the spindle and
the tools set to cut exactly the right diameter, and after being run
down to the proper depth the spindle-stop was set.
The rest was plain sailing and, except for stopping to sharpen
tools at long intervals, the pieces were turned out very rapidly
(each and every one alike) at a very small cost and much better
and cheaper than they could have been done by any other prac-
tical means. The saving in the first one hundred shells paid for
the cost of the tools.
A SPECIAL MACHINE FOE BOEING BEACKETS AND
SPINDLE-HEADS.
When constructing sensitive drill- presses of from one to five
spindles, the boring of the hole for the spindle in the upper
bracket and the spindle-head is done after all the other work has
been done and the upper column, upper bracket, and spindle -
head assembled. In the following, Figs. 244 to 247, I show and
describe a machine which was designed specially for doing this
work — that is, for boring the spindle holes in drills of from one
to five spindles.
As this tool or machine is designed to be used and fastened
directly to the columns while the holes are being bored, the pos-
sibility of error in the alignment of the spindle when assembled
is reduced to a minimum ; also, the manner of locating and fast-
ening the tool to the work while in operation is as reliable and
positive as could very well be devised for the class of work for
which it is used. The tool consists of, first, a body casting iT of
the shape and design shown in Figs. 244, 245, and 246. The
driving-spindle Y, with a tight and a loose pulley, W and IF IF
respectively, at one end, and a bevel-gear V at the other. In
the head Q is the spindle -driving gear with the two driving-
pins B B ; is the spindle or cutter-bar, and 8 the bar-driver,
INTERCHANGEABLE MANUFACTURING.
215
while H is the means for feeding the pinion, which engages the
rack, on the bar or spindle. The sets M M 31 M in the lugs
which project above the face of the plate or body casting shown,
are for bracing and holding securely the brackets and heads
III 1
nn
pi
«l
||i III
8in R F
q n R
while they are being
bored. P P, in the spin-
dle O, are the cutters,
while the adjustable
angle pieces J J, and
the clamping-levers L L,
are for fastening the rig
true and positively to
the columns while in operation.
The means and ways called
into use in the construction and
successful operation of the boring-
rig are of interest and they will
be described in turn. After the
body casting A was secured, the
first thing done was to bore and
finish the hole through the head
B and the tail 0. The size of the
hole in the head B is shown clearly
in the detail drawing in Fig. 247.
The boring was accomplished by
strapping the casting lengthwise
on an angle-plate, which, in turn, was fastened to the table of the
large drill-press — first drilling a clearance-hole through both
head and tail large enough to allow of the boring-bar (used for fin-
ishing), being entered through both the head B and the tail C, get-
Fig. 244.
216
TOOL-MAKING AND
ting them approximately central in each. A bushing which just
fitted the hole in the centre of the drill-press table, and within
which the bar would fit snugly, was then tapped in and located in
the table. This was for strengthening and centring the boring-
bar. The bar and cutters were then centred, the table clomped
in position, when the holes were bored
and finished to size required in each. The
front of the head B was then faced, by
using a cutter of sufficient width.
We were now ready to plane off the
base. This was done by first securing two
" V" blocks, with a tongue on the bottom
of each, by which they were set dead cen-
tral to each other (by entering the tongue
into the central slot in the planer bed),
and a piece of turned steel long enough
to extend about six inches outside of each
of the holes bored, and to fit each of them
snugly. The casting was then set, and
secured by resting the bar on the "V"
blocks, and clamping and casting at either
end. This made the alignment of the hole
at a true right angle with the planer-head.
The base of the casting A was then planed
perfectly fiat for its entire length, as far
as the lugs or extensions F F, which were
planed to the angle shown at 67, or the
same as that of the columns on which it
was to be used. The distance from the
centre of the hole in the head B and the
tail G to the extreme point of the planed
angle at G was exactly one-half of the
width of the dovetailed slide of the columns. This done, the
casting is removed from the planer and reset on the drill-press
by strapping to an angle-plate, and the hole bored in D for the
driving-shaft X, care being taken to get it at right angles and
central with the hole in the head and tail, and the necessary dis-
tance from it, to alloAv of the two bevel -gears C/"and Q meshing
Fig. 245.
1NTEJRGHA NGEABLE MANUFA CTUBING.
217
correctly. This hole is bored sufficiently large to allow of a
machine-steel bushing V being driven in to act as a bearing.
The hole for the rack-pinion in the bosses E E is also bored and
Fig. 246.
finished, to the size required at each end, in this setting, boring
the large part deep enough to allow of the pinion being in-
serted therein. The casting is then removed and the holes
drilled and tapped for the four set-screws M, and also the slots
for the adjusting- and clamping-levers L L let in at K K, as
shown.
The driving-shaft T was then made and finished, as shown ;
as were the two pulleys W and W W. The gear U is keyed on
and the collar X keeps the loose pulley W W in position. This
Fig. 247.
being done, we were ready to finish the construction of the head,
and spindle or boring-bar. This is clearly shown in the cross-
218 TOOL-MAKING AND
sectional drawing in Fig. 247. The first thing done was to
finish the spindle or boring-bar 0. This was turned, as will be
seen, with a collar at (2) to rest against, and also threaded for
the two jam-nuts (5). The rack (4) is fastened to the centre of
the sleeve by letting it into a channel ^-inch deep in the sleeve.
The large shoulder-bushing is then made, and is first bored and
finished to the same diameter as sleeve (3), after which it is
placed on a mandrel and turned to the shape on the outside, as
shown, there being two shoulders, one to rest against the face
of the head B and the other to rest within the counterbored
portion of the gear, the smallest diameter fitting the hole in the
head B tightly, the projecting end of the portion being threaded
for the two jam-nuts N N. The turning of the shoulders, as
shown, allows of easily locating the gear Q, which revolves free
around the outside of the bushing.
It is now necessary to plane the channel (10) through the
entire length of the bushing, as a clearance way for the rack (4).
This is done as shown, breaking completely through the bush-
ing for the length of its smaller diameter, and to the same depth
in its larger diameter, the stock left here being sufficient to
hold and keep the bushing from expanding or warping from its
original shape. r IVo holes are drilled in the face of the gear Q
to admit the driving-pins B B, which are made, as shown,
rounded on the ends, and driven tightly into the gear. The
driver 8 is then made of cast-iron and bored to fit the boring-
bar or spindle 0, as shown, being counterbored on the face to
a depth and diameter sufficient to clear the jam -nuts J" and the
sleeve 3. A key is then let into 8 at (8), which fits freely the
keyway Tin the spindle. The two holes (6) (6) coincide with
the pins B B in the gear Q. The pinion (11) and shaft or stud
(12) are finished in one piece, the stud fitting the smaller hole
in E and the pinion resting against the counterbored back of the
large one. The stud is threaded at one end for the adjusting-
nuts shown at J J in the other three views.
All parts of the head being complete, they are assembled as
shown in Fig. 247, which allows of the spindle being inserted
and withdrawn freely. After the clamping-levers L L, Figs.
244, 245, and 246, and the angular clamps J J are finished and
INTERCHANGEABLE MANUFACTURING. 219
fastened, all the parts are assembled as shown in the plan view,
Fig. 244, and the slots for the cutters F F let into the bar or
spindle in the position shown, at right angles to each other.
The rig is now ready for work.
The column, with the bracket and heads in position, is laid
flat on its back on the bench, and the boring rig (with the spindle
slipped out) placed on the first column, and fastened at G, Fig.
244, by means of the two clamps J, to the dovetailed surface of
it. The head of the bracket and the spindle-head to be bored
project up through the openings in the centre of the body cast-
ing or base A. The boring-bar or spindle O is then entered
through the head of the rig, and through the cored holes in the
bracket ahd head, and allowed to project slightly through the
tail C. The set ,- screws M at each side of the bracket-head and
spindle-head are then screwed up, and adjusted to hold the heads
perfectly rigid while they are being bored. The cutters F F
are then entered and fastened within the bar, as shown, and the
driving belt shifted from. the loose to the tight pulley. The driver
8 is then slid up, until the two pins R R in the gear Q have en-
tered the hole in it. The spindle or boring-bar is then revolving
at the proper rate of speed, and is fed in by grasping the handle
through the part H, the pinion of which engages the rack, on
the sleeve of the spindle. The spindle is fed in until the holes
are bored, when it is fed back, and the driver 8 pulled out and
the cutters removed, and another set for finishing inserted instead,
when the operation is repeated. When the bracket and spindle-
head of the first column are finished, the rig is removed and
clamped to the next one, when the operation of boring and finish-
ing is repeated, and so on, until all four heads and brackets have
been bored and finished to size.
As can be seen, the design and construction of this boring rig
allows of its use in the boring and finishing of the heads and
brackets of all sensitive drills of from one to six or more spin-
dles ; when the same design and construction is maintained in
each. It also allows of being operated by comparatively un-
skilled help, without the possibility of spoiling the parts ma-
chined by it. Its construction is simple enough to satisfy the
most exacting ; while the fact that it is located while in opera-*
220
TOOL-MAKING AND
tion directly on the columns, adds to the positiveness and accu-
racy of the work produced ; as it does also allow of the inter-
changing of the parts machined.
BORING DRILL-PRESS TABLES.
On the one-spindle drills, instead of the sliding table used on
the others, a flat swinging table and a small round one are sub-
stituted. The flat table shown at A, Eig. 248, after being
planed on all sides is required to be bored at F to fit the turned
part on the top of the column on which it swings. For finishing
this hole — which was cored — a fixture for use in the drill-press
was designed, and also a cutter-holder. The fixture, as shown in
Fig. 249, consists of a flat casting with two raised surfaces at
B B on which the table rests, and the four lugs, C C and D J>
Fig. 248.
for the locating-points. This casting, after being machined on
the back, is finished on the face by first planing the raised sur-
faces B B, and then taking a cut down the front of the lugs
C C aud D D so as to get them at right angles to each other
The centre for the hole for the bushing E is then laid out and
located so as to be central with the table sidewise and the proper
distance from the end of the other. The hole is then bored and
reamed to size required. The bushing E is then made and
hardened, and lapped and ground to size required ; then forced
tightly into the hole as shown. Holes are then drilled and coun-
terbored at the back for the clamping-bolts, G G. The two
straps are of machine steel and are bent at right angles at one
end, as shown. The straps are finished to a height sufficient to
allow r of their clamping the table securely.
The cutters and holder are shown in Fig. 249, and as will be
seen it is a plain holder with two rows of cutters set within it.
INTERCHANGEABLE MANUFA CTUBING.
221
The holder K is of cast-iron which is first centred, and turned
taper at one end to fit the drill-press spindle, as shown, and at
the other end, J, to fit the bushing E in the fixture. The largest
portion, K, is turned to a diameter sufficiently small to allow the
cutters to project out T 5 ¥ of an inch. The holes for the cutters
were drilled by setting the holder on centres in the universal
milling-machine and indexing for five, then the first row of holes
L drilled. The second row was then drilled in the same man-
ner, ^ of an inch higher up at M and so that each hole would
come between two of the first row. The cutters were made of
Stub steel f -inch in diameter, and were finished at one end for
the cutting-edge, as shown. They were then set so that the first
Fig. 249.
row L would rough out the hole, and the second row of five cut-
ters M finish it. They were held tightly in position by means
of set-screws, as shown.
When in use the fixture was strapped on the table of the large
drill-press, in the position shown in Fig. 249, by means of a bolt
through each end, at II The cutter-holder was then adjusted
so that the stem J of holder would be in line with and enter
freely the bushing E. The table to be bored was theii strapped
in position on the fixture A, locating it squarely against the lugs
G C and I) D, as shown. The stem J of the cutter-holder was
then entered into the bushing; E and the feed thrown in and the
222 TOOL-MAKING AND
hole bored and finished to size. This is the best way of finish-
ing large holes in flat surfaces of the kind shown ; the fixture
beiug both reliable and simple in construction, as well as rapid
in operation. The cutters in the holder K should be left as hard
as possible, without danger of cracking, so as to allow of finish-
ing the maximum number of holes without the necessity of fre-
quent removal and grinding.
MACHINING BOUND TABLES.
In Fig. 250 is shown two views of the round table as used for
the small presses. This table is in two parts — N, the table proper
of cast-iron, aud 0, the stem of cold-rolled mild steel. The man-
ner of finishing the tables is as follows : The casting is first
chucked in the turret-lathe and the hole bored and reamed for
the stem; reaming it about 0.003 less than the diameter of the
stem O. The stems are simply cut off from the bar in the screw -
machine, and slightly chamfered at each end. The tables are
then heated in a gas- muffler to a dark red,
// \\ when the stems are inserted so as to project
/ ' ('r>Y° ylm slightly above the face. This way of fastening
ij\ the stems is the best, as it is both rapid and
^y J permanent. After the tables have cooled suf-
ficiently to allow of being handled, they are
l i i H ili l lllll i liL— n f ace( l au( l the rim turned by holding them by
the stems O in the universal chuck in the lathe.
[^q They are then transferred to the grinder, where
the face is ground. This gives it a neat and
mechanical appearance, as well as finishes the
rii*. 250.
face perfectly flat.
The finishing of flat surfaces by grinding, as in the above
case, is far preferable and more expedient than the one usually
employed — that is, taking finishing cuts in the lathe, which is
an obsolete way of doing it and very slow, especially when a per-
fectly flat surface is required on the finished work.
FINISHING CUB CENTRES.
In finishing the cup centres shown in Fig. 251 they are first
turned on the stem P to the same diameter as the table stems.
INTERCHANGEABLE MANVFA GT URING.
223
They are then fastened by the stems in a nose-chuck in the lathe
and the inside turned to a sixty degree angle by using the com-
pound rest, and a special holder in which self -hardening steel-
cutter is fastened.
ADVANTAGES IN THE USE OF SPECIAL TOOLS.
In this chapter, and those precediug it, the number and
variety of tools and fixtures which have been shown and de-
scribed for the duplication of parts have been suffi-
cient to fully demonstrate the advantages to be gained
in manufacturing by the use of special tools as com-
pared with the old methods. Also, it may be well
to mention that the use of such tools eliminates the
necessity of the results attained in the work de-
pending on the skill and intelligence of the work-
men, and allows of employing less expensive help
in the manufacturing of various parts. While the
tools shown in this chapter are the simplest and least expen-
sive of their class, if by the study of them they will be
the means of converting some of a the-old-way-is-good-enough-
for-me " sort of shops, to the adoption of the system of inter-
changeable manufacturing, they will have more than served their
purpose.
Fig. 251.
CHAPTER XV.
Design, Manufacture, and Use of Milling-Cutters.
MILLING-C [JTTEKS CLASSIFIED.
It goes without saying that the king of all modern cutting-
tools is the milling- cutter; for that reason it cannot be too fine a
piece of workmanship. Of what use would be the plain or uni-
versal milling-machine without it? In fact, when considering
milling-cutters it is well to remember that the milling-machine
was created for it and that all the genius and excellent workman-
ship put into these wonderful machines are for no other pur-
pose than to rigidly hold and revolve the cutter or cutters at the
proper speed, and to feed the work to it at a rate suited to the
material being milled and the type of cutter doing the work.
Milling-cutters may be classified in four distinct types. The
first and probably the most common form is known as the axial,
Fig. 252.
FIG. 253.
Fig. 252, in which the surface cut is parallel to the axis of the
cutter. This cutter has teeth on its periphery only ; these may
be straight or spiral teeth. Cutters of this character, made in
appropriate widths, are used very much for milliDg broad, fiat
surfaces and for cutting key ways in shafts. For deep cuts, or
for slitting metal, they are made of large diameter and thin.
These are called metal -slitting saws, and are ground hollow on
the sides for clearance.
224
INTERCHANGEABLE MANUFACTURING.
225
The second class of cutters is known as the radial, Fig. 253,
in which the surface cut is perpendicular to the axis of the cut-
ter. These cutters are called radial because their teeth are used
in a plane parallel to the radius of the cutter. End-mills, face-
mills, butt-cutters, etc., are all tools in this class.
The third class of cutters is the angular, Figs. 254 and 255,
in which the surface cut is neither parallel nor perpendicular to
FIG. 255.
WORK/%%?
w///wW//mW/W//.
Fig, 256.
the axis of the cutter, but is at some angle with this axis. Fre-
quently cutters are made with two different angular cutting edges,
in which case the angle is marked on each side, as in Fig. 255.
The fourth class of cutters is the formed cutter, as shown in
Fig. 256. The cutting-edge of this class is of an irregular out-
line. When properly backed off, these cutters can be ground
and retain their original form. Gear-cutters, tools for grooving
taps, etc., are all classed as form cutters.
Among the numerous engravings in this chapter will be
found illustrations of a large number of cutters which are used
in milling-machines. In most cases it is advisable to use a cut-
ter of small diameter rather than of large diameter. Cutters
from \\ to 2 inches in diameter are the most economical for gen-
eral milling.
THE DESIGN AND MANITFACTUBE OF MILLING -
CUTTEES.
It is conceded to-day that one of the chief factors in bring-
ing the process of milling into universal use and to the front
15
226 TOOL-MAKING AND
rank of machine operations, was the introduction of the emery
wheel for grinding milling-cutters.
So much attention has now been given to the milling process,
that in many cases a degree of perfection has been attained which
apparently leaves little room for improvement. It is still true,
however, that even in up-to-date shops the output is below what
it might be. Some firms undoubtedly have developed milling
far beyond the rest of the country, but as a whole there is no
reason why milling should not continue to advance during the
present decade as much as it did in the past one. It should
advance not only in becoming more general and more widely
applied but also in the direction of giving better results.
STANDARD STYLES AND SIZES OF CUTTER.
It is now quite a common practice to use cutters which are
not adapted to their work. The number of standard styles and
sizes of cutters is already enormous, and neither the manufac-
turer nor the user can contemplate with equanimity the idea of
a large increase, and yet the existing standards are inadequate
for the great variety of work they have to perform. The ordi-
nary standard cutter is intended to be used on cast- or wrougbt-
iron, steel, or brass, and the recognized form has been evolved
as the best compromise for varied work.
There are many special operations where the cutter passes,
through different metals at the same time, or through mica, or
raw-hide or paper, or where any curious conditions arise ; and
the best form of cutter can only be arrived at by experiment on
that particular operation. For an individual job it matters little
that a cutter is not the very best design, but with repetition work
it is serious to use a tool which is not capable of giving the best
results.
UNDERCUT TEETH.
A turning or planing tool for iron or steel has top rake, as
well as clearance below, and milling -cutters for many operations
should have similar rake. From experiments, and from general
experience, it has been demonstrated that undercut teeth may
INTERCHANGEABLE MANTJFA GTUBING.
227
often be used with advantage under the following conditions:
The machine should be powerful, and the cutter-arbor of ample
size. The pitch of the teeth should be so coarse that only two
or three may cut at the same time. The speed of cutting should
be slow, and the feed sufficiently quick to allow each tooth to
take a real cut. When these con-
ditions cannot be fulfilled, there
will probably be no advantage in
departing from the usual form of
tooth.
Slotting- or grooving-cutters,
spiral cutters, and side-mills are
well adapted for undercut teeth.
Formed cutters may be so made,
but there is a difficulty with the
form. Thus, in Fig. 257 if the true form required is made along
the cutting face A B, the cutter will leave a false form to the line
A C. The difference is in most cases very slight, and always may
be allowed for in making the cutter, but variations in grinding
the face will alter the form. It is easy in grinding them to see
when the faces are radial, but it is not so simple to give a known
amount of rake.
END-MILLS.
Fig. 257.
The question of undercut teeth also arises in the case of end-
mills. Three methods of cutting the teeth are shown in Figs.
258, 259, and 260. Fig. 258 shows an ordinary spiral end-mill
FIG. 258.
Fig. 259.
with right-hand teeth and left-hand spiral, by which arrangement
the pressure from the work always tends to push the cutter into
its socket. This is the correct form if the cutter is to be used
for milling on the sides, if, strictly speaking, it is not to be
used as an end-mill, for which it is unsuitable, because the
teeth on the end have negative clearance and would not cut
228 TOOL-MAKING AND
freely. For end-cutting, the ordinary straight teeth shown in
Fig. 259 are more suitable, and in some cases a right-hand cutter
with a left-hand spiral would be best of all (see Fig. 260). This
Fig. 260.
gives correct clearance to the end teeth, and when used under
favorable conditions such a cutter has no more tendency to leave
its socket than a twist-drill, which is made on exactly the same
principle.
SIDE CLEARANCE.
Standard cutters frequently give trouble in the matter of side
clearance. It is assumed that the cutter must not lose its width
on resharpening, but there must be some dishing on the sides, or
it would be unworkable ; accordingly a very slight clearance is
given, say one-half degree each side, which will cause the cutter
to become two-thousandths (0.002) thinner when ^-inchhas been
ground away in diameter. The cutter would be more service-
able if it had, say, one degree clearance each side, but that would
cause it to lose its width too soon. Now suppose a quantity of
work is required where the width of groove is not particular to
one-fiftieth (0.02) of an inch, or where the cutter is only used for
roughing, it would be worth while to take a standard cutter and
grind extra clearance on it. This is particularly the case when
cutting brass, which is very liable to bind on the sides.
INSERTED TOOTH-CUTTEES.
The time has now arrived when a great development should
take place in the direction of cutters with inserted teeth. The
obvious advantages are :
1. That cheap material may be used for the body of the cut-
ter, and the very best high-speed cutting-steel for the blades.
2. Hardening difficulties are reduced to a minimum.
3. When worn out the blades may be replaced at a small ex-
pense.
INTERCHANGEABLE MANUFA CTUEING.
229
The great objection is the first cost, particularly in the case
of cutters less than about seven-inch diameter. Also inserted
blades are usually not very suitable for wide cuts. The supe-
riority of the inserted tooth-cutter is most unquestionable in the
case of side- or straddle-mills which are mainly cutting on the
corners.
One widely used method of holding the blades is shown in
Fig. 261. "the blade A is ground on the sides. The bush B is
turned parallel and has a flat milled on it at an angle with the
X
SECTION X-Y
FIG. 361.
centre line. This bush, which fits in a recess, as shown, is sim-
ply a wedge and is knocked in. There is a screw G to prevent
it coming loose. A second screw D, a patent one, is shown for
adjusting the blades side wise. There seems to be no reason why
these cutters should not largely displace solid side-mills except
in the smaller sizes.
LIMITS OF INACCURACY.
Coming now to the manufacture in quantities of cutters, the
great principle of "good enough " asserts itself. It must first be
determined exactly what "good enough" is, and the drawing
must show that exactly. Any time spent in making a measure-
ment nearer to a dead size than is called for is a loss. Fig. 262
is a working drawing of a simple cutter which is to be measured
with the micrometer, and not with limit-gauges.
According to this drawing, it has been determined that if
error in the thickness of a |-inch cutter does not exceed one-
thousandth (0.001) of an inch, it is good enough. This is clearly
shown, and the grinder must adhere to the limits given, but must
230
TOOL-MAKING AND
not waste time in making every ^-inch cutter to within one-half
thousandth (0.0005) of the nominal size.
Again, it has been found that about one-hundredth (0.01) is
a reasonable allowance for cleaning out the turning marks on
the sides after hardening. It is, how-
TFETH 24
ever, quicker to grind off a few extra
thousandths than to turn them off,
and the lathesman must keep within
the limits — ten to fifteen thousandths
above -|-inch. £:J4|. He has no ex-
cuse for leaving too much or too lit-
tle for grinding, nor yet for wasting
time by taking a cut of two thou-
sandths (0.002) off the side.
It is shown that the actual diam-
eter is not important, and the lathes-
man has a limit of one-hundredth
(0.01) of an inch, which means that
the grinder must just clean out the
turning marks.
The drawing shows that the side
recesses may vary in diameter by one-tenth (0.1) of an inch.
The clearance each side is stated as one-half degree, and it is
essential that this shall run out to the extreme tips of the teeth.
USE AND ABUSE OF CUTTEES.
A whole chapter might well be devoted to the use, abuse, and
maintenance of milling cutters. A slignt reference only can
be made to this branch in a chapter dealing mainly with their
design and manufacture.
It is a source of great satisfaction to the maker that when a
cutter is broken by being run backwards on to the work, the
breakage is characteristic. A cutter may be taken that has been
spoilt in this way, and although the man who broke it will be
absolutely sure that it ran in the right direction, the cracks
down the faces of the teeth tell a different story.
On many operations it is of the first importance to have a
full flood of lubricant ; a trickle is not sufficient.
INTERCHANGEABLE MANUFACTURING. 231
EEGEINDING.
It cannot be too strongly insisted that it is very wasteful to
use a dull cutter. It is as hopeless to mill successfully without
adequate grinding arrangements as it would be to turn satisfac-
torily with only the door-step to sharpen the tools on. When a
cutter is changed in time, the sharpening should only occupy a
very few minutes for most small sizes. If run too long, the
grinding becomes a serious operation, which causes the grinder
to lose his temper, and to draw the temper of the cutter.
When the resharpening cannot be accomplished by two or
three passes over the emery wheel, the cutter should be mounted
on a mandrel and ground whilst revolving until the worn part
has all been removed ; and the tooth-by-tooth grinding should
be reserved for backing off to give the cutting edge. Not only
is this much the quicker way, but there is no risk of drawing the
temper if ordinary care be exercised.
It must always be remembered that however good a cutter is,
the cutting-edge may be so damaged by a little carelessness in
grinding as to receive any degree of injury up to the point of
being ruined. It is well to touch the cutting -edge with an oil-
stone after grinding.
As the teeth are usually reground on a dry wheel, it is impor-
tant that arrangement should be made for exhausting the dust
produced. Dry grinding is now recognized as a dangerous occu-
pation, causing lung diseases. The operation is not capable of
imparting consumption itself, but it so irritates the throat and
lungs as to keep them in an unhealthy condition and render them
susceptible to consumption germs. For this reason the emery
wheel should be enclosed, as far as possible, in a hood, and a
good exhaust provided by a fan or other suitable means.
QUALITY OF STEEL TO USE FOE MILLING-
CUTTEES.
The all-important question of the quality of steel to be used
is too often ignored. Self-evident as it is, the fact may yet be
overlooked that two cutters, one made of the best steel and
232 TOOL-MAKING AND
one of the worst, may be identical in appearance, and the differ-
ence will only become apparent in use.
In small or complicated cutters, in which the cost of steel is
only a small proportion of the total cost, the amount saved by
using cheap steel is- slight.
In large cutters of simple forms with little machining on
them, where the cost of steel is perhaps one-third or even one-
half the cost of the finished cutter, the saving effected by using a
poorer quality of steel amounts to a great deal, and may recon-
cile the user to an inferior cutting edge. Good steel may be re-
cut, and after the hardening the cutter should not be perceptibly
inferior to a new one.
SELECTING A SET OF CUTTEES FOE A MLLLING-
MACHINE.
A person buying a milling-machine for general use, who has
not had previous experience, is immediately confronted with the
problem of cutters, and the questions are frequently asked, " What
should I buy for a starter? " and "What is likely to be required
for my work ? " It is to this class that these suggestions are
offered rather than to those who by years of experience and
study are prepared to give counsel and are not in need of what
I have to offer.
To begin with, do not under any circumstances buy up a lot
of second-hand cutters because they can be had at a bargain, as
they are liable to prove very expensive in the end for many rea-
sons. They may be unsuited for the work, out of date in design,
and will unconsciously be copied in the new cutters that are
made, or they may be worn away so that further grinding is im-
possible and consequently useless.
AN ASSOETMENT OF MILLING-CUTTEES.
The assortment of cutters shown in Fig. 263 makes a good set
to put with the new milling-machine. A wide range of work
can be done with them, including the making of new cutters of
almost any style or size. This set consists of two of No. 6 and
one mill arbor, suitable for shell -end mills from 2^ to 5 inches
INTERCHANGEABLE MANUFACTURING.
233
in diameter, and No. 7 illustrates an end-mill 1\ inches in diam-
eter to fit it. The arbor has a threaded collar with tongues to fit
in the slots milled in the back end of the cutter for driving it.
The screw tapped into front end of the arbor drops into the
counterbore in the • cutter, thus keeDing out of the way of the
chips and holding the cutter in place. Figs. 264 and 265 show
two other styles of end-mills and arbors, each having something
to recommend them. The cutters shown in the group at the
right are tapped standard, and have a slot milled across the
back end to fit the loose collar, which is used to force off the cut-
ter and serve no other purpose. If desired, the cutter itself
could be extended and milled to fit a wrench, the only objection
being that the cutter would be slightly more expensive.
The arbor shown with cutters to fit in Fig. 264 has No. 10
B. & S. taper to fit in the machine, No. 4 Morse taper in front
Fig. 264.
FIG. 265.
to fit the cutters, and Woodruff key to do the driving. It has a
nut to force the cutter off and a screw to hold it on, the same as
the screw in No. 1 of Fig. 263.
These three styles of arbors and cutters are excellent and any
one of them will give good results. The threaded cutter is the
234 TOOL-MAKING AND
cheapest because it does not require internal grinding or lap-
ping. The taper-arbor and its cutter are perhaps slightly more
expensive to make, because it is necessary that the cutter be
ground internally to fit the taper. This is to be recommended
when the most accurate work is required.
SHELL END-MILLS.
Shell end -mills are very useful cutters and will be largely
used wherever a milling-machine is supplied with them.
Small end-mills should be made solid, perferably with taper-
shanks (Nos. 3 and 4, Fig. 263), as the most accurate and satis-
factory way to hold them.
SPINDLE SURFACE-MILLS.
The spindle surface-mill (No. 5, Fig. 263) is 2^ inches in
diameter, 3 inches face, and is one of a great variety listed by
the cutter manufacturers whose practice is to make with straight
Fig. 266.
teeth where the face is less than f-inch wide. This style of cut-
ter, in widths to suit, is commonly used for key-seating.
Cutters with side teeth (No. 6) could be used for key-seating,
but it is obvious that they would fall below size much sooner
than the cutter with outside teeth.
Teeth milled spiral will do better work on wide cuts than
INTERCHANGEABLE MANUFACTURING. 235
when milled straight, on account of the shearing out, and for
heavy roughing the teeth should be nicked by cutting a coarse
thread around the blank before milling the teeth.
The side-cutter is most useful in pairs for milling both sides
of a piece at once, like squaring a tap-shank ; the cutters oper-
ating on opposite sides of the piece take away any tendency to
spring and produce accurate work rapidly.
GANG-MILLS AND INTEBLOCKING CUTTEBS.
A gang of spiral surface -cutters with side teeth, the inner pair
made interlocking, is shown in Fig. 266. The teeth are cut
spiral, right and left hand alternately, to balance any side-thrust
and to give top rake to the side teeth doing the cutting. The
inner pair are made with clutch teeth to interlock ; the bearing-
faces being scooped out to allow the clutch teeth to engage.
Paper is used to extend the cutter as the sides are ground away,
maintaining a constant size and insuring interchangeability.
The same cutters can also be used for roughing and finishing by
taking out some of the packing while roughing, and restoring
the cutters to the proper width before taking the finishing cut.
Fig. 266 shows a group of common forms. Care should be
taken in grinding to have the face of the teeth radial ; the ten-
dency is to grind the point more than the base of the tooth, which
places the cutting-edge at a great disadvantage.
Generally it is more economical to buy standard cutters from
the maker, and in many instances special ones also, but it is at
times desirable to do some of this work at home, being cheaper
if the tool-room is properly equipped and organized, and the
educational advantage of such work has a distinct value.
MAKING CUTTEES.
For making cutters, Kos. 10, 11, and 12 of Fig. 263 provide
a good outfit. The first two have sixty degree angles, one right
and one left hand, and will suffice for most straight tooth work.
No. 12 is for milling spiral cutters and has twelve degree angles
on one side and forty degree on the other.
Practice has shown that it is best to make cutters with radial
236 TOOL-MAKING AND
teeth. If they are undercut so as to give the cutting-edge top-
rake, as in a lathe-tool, it makes a weak tooth liable to break
easily, but adds to the efficiency of heavy ones.
There is far more danger of getting too many teeth than too
few into a cutter.
If the cutter is small in diameter so that it will become too
thin if the teeth are deep, take the first cat through at the proper
depth and then mill around again after revolving the work so as
to bring the proper angle.
MOST VITAL POINT IN MILLING-MACHINE
PEACTICE.
The most vital point in milling-machine practice is that cut-
ters of whatever design be kept sharp. A dull cutter is like
any other tool that is dull — its efficiency is greatly reduced, the
work produced is inferior, and the cutter wears rapidly away.
The same principle applies to the cutting-edge of the milling-
cutter as to any other cutting-tool for metal. If too little clear-
ance is ground it will not cut well, and if too much, it will chat-
ter ; about three degrees will generally give good results.
SPEEDS AND FEEDS FOE MILLING-CUTTEES.
A subject upon which too much cannot be written nor
thought given is that of proper speeds and feeds for milling-
cutters. Often the question is asked: "What lule is there for
determining the proper speeds of cutters. " When a direct an-
swer is not given to this question, the questioner is always dis-
satisfied and usually discouraged. Of course there is no "hard
and fast " rule for determining the proper feeds and speeds of
cutters, and in this book one cannot be given. The texture and
hardness of the material to be machined determines the surface
speed in each case. Thus, for cast-iron, a speed of forty feet
per minute may be safely taken as a good basis when taking
heavy roughing cuts, while for light finishing cuts on the same
material, (after the scale has been removed) fifty feet per minute
is not too fast. When working steel twenty feet per minute is
INTERCHANGEABLE MANVFACTURING. 237
not too fast, and for brass sixty feet per minute is a good basis
for determining the correct cutting speeds for these metals.
Although the hardness and texture of the material worked
upon is the chief factor to be considered when determining mill-
ing speeds, the nature of the cut and the shape are also very im-
portant factors. Thus, for instance, a large slitting-saw can be
run about twice as fast as a large surface -cutter when working
on the same material.
JS~ow, with regard to the rate of feeds for milling, the most
advanced practice is to take a roughing-cut with the fastest feeds
the macbine will pull ; that is, provided the cutter is relatively
as strong in comparison as the machine in which it is used. If
the nature of the work requires a cutter of such a form as to be
comparatively weak, it is often better economy to break an occa-
sional cutter than to allow the machine to work at a slow rate of
speed.
When running a cutter at a slow rate of speed and advancing
it at a fast rate of feed on cast-iron, compressed air, delivered to
the cutter with sufficient force to clear away all chips as fast as
Fig. 267.
they are produced, will j>rolong the life of the cutter, even when
the fastest feeds are fed against it. When working steel, a
stream of oil on the cutter will have the same effect, providing
the oil is delivered under pressure sufficient to wash away the
chips entirely from the cutter.
In regard to " burning " cutters, or drawing the temper while
working them, it must be understood that this will not happen
through too fast a feed, but it is always to be traced to too high
speeds. Thus, when both speed and feed are up to the maxi-
mum, the actual rate of table travel per minute can be further
238 TOOL-MAKING
increased by reducing the speed of the cutter and increasing the
feed rate.
When taking finishing cuts, the rate of speed depends upon
the quality and degree of finish required. Here it may be
stated that experiments have determined that 0.030 per revolu-
tion of a 3^-inch cutter when surface-milling leaves a good fin-
ish, and in machine work will leave a surface that will require
little scraping to make a good bearing.
Fig. 267 shows a collection of forming cutters.
To succeed with milling-cutters they should be made right,
hardened properly, sharpened regularly, and speeded and fed
properly.
SUGGESTIONS FOR MILLING.
Experience in the use of milling-cutters will teach anyone
that unnecessary expense and annoyance may be avoided by fre-
quent and proper grinding of milling-cutters. A dull mill will
not do good work and wears away very rapidly. At the first
appearance of dullness, use your cntter-grinder, it will save
your cutters, your time, and your patience, and will enable the
cutters to do their best and most rapid work.
In order to preserve the correct shape of formed corners,
grind the teeth radially.
No definite rule can be given for speed or feed of cutters, but
the usual tendency in all classes of Avork, except for finishing
cuts, is for slow speeds and coarse feeds.
For cutting wrought-irou or steel use lard, oil, or some one of
the usual compounds manufactured for this purpose.
Small mills on horizontal millers will cut better and faster
than larger mills ; they also cost less and will last longer.
Wherever possible use a mill that>is wider than the cut to be
taken.
CHAPTER XVI.
The Hardening and Tempering of*T\ffilling-Cutters.
HAEDEOTNG.
Although the quality of steel used for milling-cutters is of
great importance the proper hardening of it is eepially so. It is
a fact that bad steel well treated will make better cutters than
good steel poorly treated. The hardeners of such tools cannot
complain of a lack of literature, as treatises and articles on the
subject are continually appearing. However, practice alone can
teach the details and refinements of the most interesting process
in the making of milling-cutters.
In the following, methods are put forward for the proper
hardening of milling cutters which are the result of experience,
and while they are not necessarily the best, it is claimed that
they have brought success when used.
It pays to spend time on filling blind holes, sharp internal
angles, etc., with clay. In many cases asbestos should be used
with wire over a weak place, or over a part which must be kept
soft. The furnaces should be in a partially darkened room
from which direct sunshine is excluded.
Though I have never found any disadvantage in using cold
water for quenching, it is quite reasonable to suppose that water
containing a considerable amount of air dissolved in it may not
cool the cutter so uniformly as it would do if the air had been
expelled, and therefore boiled water is to be preferred.
After machining, tools should have a few days rest before
hardening. If they must be hardened immediately, they should
be annealed first, but care must be taken to prevent a tendency
for the surface to become decarbonized. To accomplish this, an
excess of charcoal should be kept near the cutters in the furnace
to maintain a reducing atmosphere.
239
240 TOOL-MAKING AND
HEATING.
It is not only necessary that the cutter should be at the right
heat, and at a uniform heat, when plunged, hut it must have
reached that heat gradually and uniformly. If the heat be applied
gradually, the cutter may be made hotter than the correct tem-
perature, and yet not crack. If a crack appear under these cir-
cumstances, it will probably go through the cutter. If a cutter,
after being heated too rapidly, or allowed to get much too hot,
be carefully brought to the right temperature in the furnace and
then plunged, the teeth may clink off. They are certain to do
so if it be not nearly uniform in temperature at the time of
plunging. In case of a mistake in heating, a cutter should be
allowed to cool out, and heated fresh.
PLUNGING.
The manner of plunging is worth attention. A thin cutter
should be in a vertical plane when it enters the water. If it
were plunged horizontally, one side would be cooled before the
other, and would cause the cutter to warp. A cutter with a long
hole should be plunged into the bath with the hole vertical, to
allow the water to circulate freely. Cutters with large recesses
should be plunged with the recess uppermost — to allow the steam
to escape. The object generally is, in the first place, to cool
symmetrical parts simultaneously ; and, secondly, to let the water
have free access to every part without delay. Thus a long thin
reamer should obviously be dipped endwise, in order that all
the flutes may cool simultaneously, notwithstanding the fact
that the water would come into contact with every part in a
shorter time if it were dipped horizontally.
Cutters need not be cooled right out in the water. They may
be removed as soon as they are so far chilled that the temper
color would barely show if they were polished immediately.
Cutters of a few pounds weight may be lifted from the water as
soon as the teeth are chilled. In a few minutes the heat from
the inside begins to reheat the teeth, and just before the color
shows they must be plunged again for a second or two. This
INTERCHANGEABLE MANUFACTURING. 241
may be repeated three or four times or more, according to the
size of the cutters. When at last they are cool enough, they
should be maintained for a few minutes at a heat sufficient to
just show color — a light straw — and then allowed to cool out in
the air. In order to see the color, it will be necessary to have
another piece with a clean surface for comparison.
WARPING.
Change in shape in hardening may be largely prevented by
previous annealing, by keeping to the very lowest temperature
that will give sufficient hardness, and by the utmost uniformity
of heat in every part.
LEAD BATH.
Long thin reamers may be uniformly heated in red-hot lead.
It is, however, important, in order to prevent the lead from
being cooled by the immersion of cold articles, and also to avoid
injury to the articles themselves by too sudden heating, that
reamers or other articles should be independently heated to a
red just below the hardening temperature, and the lead bath
should be reserved for the final heating, the lead should be that
sold as "chemically pure, " and when in use there should be a
great abundance of small charcoal floating on the surface to pre-
vent the formation of dross which would cling to the teeth.
DEGREE OF HARDNESS.
Whether heated in lead or not, the teeth of a finished cutter
should be as hard as a good, new, smooth file. They should
scratch glass.
INJURY IN HARDENING.
It has been stated above that steel may be overheated, and
yet not crack if the heat be very uniform. This point must be
strongly insisted upon, and claims careful attention. It means
that we must not regard breakage as a dividing point between
good and bad hardening. It is the division between bad and
worse. When steel is badly treated, it will lose its best propor-
242 TOOL-MAKING AND
tion long before the treatment is so very bad as to cause actual
rupture. If in a large hardening a considerable quantity of tools
are broken, it is probable that many of the remainder are as bad
as they can be without actually breaking ; but if none are broken
it is reasonable to assume that many are well hardened. A good
hardener need not be afraid of occasionally getting a cutter
barely hard enough or just doubtful in hardness, because a heat
which accomplishes this will do the steel no harm, and it may be
rehardened; meanwhile the operator has the satisfaction of
knowing that the remainder of the day's work is probably very
accurate indeed.
There are then two extremes which are unquestionable. A
cutter which on the one hand is not hard enough, or on the other
hand is broken, evidently cannot be passed.
TEST OF HABDENLNG.
As steel may be between these obvious limits and yet be
damaged, a finer test is demanded, for if the hardener is to hit
the exact point he must know exactly what success he has.
SAND-BLASTING.
For this purpose the following method has frequently been
adopted with success. After being hardened and tempered in
the usual manner, the cutters are dipped in oil and then sand-
blasted. If there has been any overheating in the furnace,
though not enough to do any apparent harm, cracks will appear
on the faces of the teeth. These cracks, which are best seen im-
mediately after sand-blasting, are frequently so small that they
cannot be detected by ordinary means, and if the teeth are
broken off the breakage will probably not follow them. A cut-
ter on which the sand-blast reveals numerous cracks may still be
quite passable — indeed, it would have been considered perfect
but for this test. Here is a means of trying the work of the
hardener between narrower limits, and he has a warning that he
is giving too much fire before a tool is spoilt.
The sand-blasted cutter also possesses another advantage of
some importance in the fact that if the temper be drawn in
INTERCHANGEABLE MANUFACTURING. 243
grinding sufficiently to cause any discoloration, the tell-tale line
will show distinctly on the face of the tooth, and cannot be re-
moved by another pass along the wheel.
HEATING AND HAEDENING LAEGE CUTTEES.
The following method of getting a good uniform test on a
large cutter, say about 9 inches diameter and 2£ inches thick, in
an ordinary blacksmith fire is over good, and if followed out
carefully will result in perfect satisfaction.
After getting a good deep fire, with plenty of well-coked
blacksmith's coal as a foundation, and having the sides of the
fire well banked up with fresh coal, the cutter should be placed
in the fire and covered over with "live" coals of coke and the
whole brought up slowly until the cutter begins to show some
red.
Then place some dry pine boards, about one inch thick, over
the top of the fire and almost entirely shut the blast off. The
boards of course will take fire and soon become live coals. The
cutter should then be turned over and a second layer of boards
placed over the fire.
By the time these are burned to good live coals we will have
a thorough, uniform heat. Then after a slight application of
the blast, so as to be sure to quench on a rising heat, and two or
three turnings of the cutter in the fire, in order to keep the heat
uniform, the cutter will be ready to quench.
This may be done in "brine," allowing the tool to remain in
the bath about fifty seconds. Then quickly withdraw it and
place it in a tank of oil to finish cooling. The heating should
take about thirty-five minutes.
Although a good gas furnace should be used for such a job
as the above, I realize that this is not always to be had when
wanted.
Finally, of hardening, it may be said that it is the most diffi-
cult and the most interesting part of cutter-making.
CHAPTER XVII.
Drills and Drilling, Forming-Tools, Facing-Tools,
Counterbores, Boring-Bars and Reamers.
BOEING-BARS AND REAMERS.
In this chapter will be found much information, compiled
from personal experience, the columns of technical journals and
notebooks of fellow mechanics — which will assist the tool-maker
in the designing and constructing of any special small tools
which may be required for special work in the line of drilling,
counter-boring and boring.
DEEP-HOLE DRILLING.
* The process of drilling deep holes in metal is a familiar one
in many shops, particularly where firearms are manufactured or
heavy ordnance is constructed. Since the adoption of hollow
spindles for lathes and other machine tools, the methods for
machining the bores of guns have been employed in machine-
tool shops for drilling these spindles ; and through this and the
other means the principles of the operation have become better
understood. It is not an easy matter, however, even with the
best appliance, to drill or bore a deep hole, smooth and round, of
exactly the required diameter from end to end, and perfectly
straight. While many mechanics are familiar in a general way
with the methods and tools for doing this work, some specific
information upon the subject will be appreciated by those who
have not had actual experience in deep-hole drilling.
It is known that a long or deep hole — that is, one long in
proportion to its diameter — is best roughed out and finished by
using a tool on the end of a long bar, which enters the work
from one end. This is true whether drilling into solid metal or
boring and reaming a hole that has already been drilled or bored
* "Machinery."
244
INTERCHANGEABLE MANUFACTURING.
245
out. A boring-bar which extends through the piece and on
which is either a stationary or a travelling head, is not satisfac-
tory for very long work, owing to the spring and deflection of
the bar, which is made worse by the fact that the bar must be
enough smaller than the bore to allow room for the cutter-head.
While a long hole may sometimes be finished satisfactorily by
means of such a boring-bar, by packing the cutter-head with
wooden blocks which just fill the part of the bore that has been
machined and so support the bar, the method is fundamentally
wrong for long work.
THE TWIST-DEILL.
The modern twist-drill accomplishes all that is attained by
the arrangement in Fig. 268, and in addition can be ground
Fig. 268.
without seriously affecting the rake, and will free itself from
chips more readily,* owing to its spiral flutes. The lands of a
twist-drill present a large cylindrical surface to bear against the
sides of the hole and take the side-thrust. If the drill is also
guided by a hardened bushing, at the point where it enters the
OIL PIPE FROM PUMP
OIL AND
CHIPS RETURN
THROUGH PIPE
FIG. 269.
metal, as in the case of jig work, the drill will have very little
chance to deflect and the hole will be accurately located and will
be quite true and straight.
2J.6 TOOL-MAKING AND
The twist-drill in modified form is also employed for deep
hole drilling. The hollow drill shown in Fig. 268, and intro-
duced by the Morse Twist-Drill Co., New Bedford, Mass., is
adapted for this purpose, and in Fig. 269 is the arrangement rec-
ommended by this company for feeding the drill into the work.
The drill has a hole lengthwise through the shank, connecting
with the grooves in the drill. The shank can be threaded and
fitted to a metal tube which acts as a boring-bar and through
which the chips and oil may pass from the point of the drill.
Oil is conveyed to the point on the outside of the tube, as shown
in Fig. 269.
In using the hollow drill the hole is first started by means of
a short drill of the size of hole desired, and drilled to a depth
equal to the length of the hollow drill to be employed. The
body of the hollow drill acts as a stuffing, compelling the oil to
follow the grooves and the chips to fall out through the hollow
shank. The methods of supporting and driving the work, and
of feeding the drill, are clearly shown in Fig. 269. Drills of
this type are regularly manufactured in sizes up to three inches
in diameter by the Morse Twist-Drill Co. It is stated that the
best results are obtained when drilling crucible steel by revolv-
ing the drill twenty feet per minute, with a feed of 0.0025-inch
per revolution, while machine steel will admit of a speed of
forty feet per minute, and a feed of 0.0035-inch per revolution.
NUMBER OF CUTTING-EDGES DESIRABLE.
When drilling a hole out of solid stock, some type of drill
having two lips or cutting-edges is usually the most feasible,
and probably nothing will be devised that on the whole surpasses
the twist-drill for such work. An end-mill can be used for drill-
ing if it has a "centre cut," aud it will presently be explained
how a tool with a single cutting-edge may be advantageously
employed, particularly for deep -hole drilling. The familiar
D -drill is of this type, and also its modification as used by Pratt
& Whitney, in drilling gun -barrels.
When it comes to truing up or enlarging a hole previously
drilled or bored, the two-lip drill is not suitable in any of its
INTERCHANGEABLE MANUFA CTTJBING.
247
forms. For boring a true hole, nothing can surpass a single-
pointed boring -tool, the ideal condition for finishing a hole being
when the cutting-point is a real diamond, or a rotating wheel of
abrasive material.
It is obvious that when a hard or soft spot is encountered in
boring with a tool having a single cutting-edge, only that par-
ticular place is affected by the spring of the tool ; while with a
Fig. 270.
Fig. 271.
Fig. 272.
Fig. 273.
double-cutter, as shown in Fig. 270, any deflection due to irregu-
larities, such as at a or b, will cause the tool to spring and the
cutting-edge on the opposite side to introduce similar irregulari-
ties in the opposite side of the hole. This is one objection to
the two-lip drill for accurate work. *
With three points the tool is somewhat better supported when
a high place is countered, as at Fig. 271, and when a cutting-
point strikes a low place, the other two edges are not moved
away from their position so much, if they are opposite the first
edge. Hence a tool with three edges should prove better than
one with two, and one with four, Fig. 272, being better sup-
ported, is better on this account than one with three, but has the
disadvantage of opposite cutters. Five edges, Fig. 273, ought
to give even better results.
In general it may be said that in boring the best results are
obtained when the tool has a single cutting-edge, but if it is de-
sirable to have more cutting -edges, a tool with several will be
more satisfactory than one with only two. Any machinist who
has tried to true up the taper hole in a lathe -spindle, first by
boring and then by reaming, will appreciate the superiority of
the boring-tool over the multiblade reamer. A reamer some-
times refuses to produce a perfectly round hole and will do this
248
TOOL-MAKING AND
whether the number of teeth is odd or even, and this can only be
prevented by spacing unequally or "staggering."
ADVANTAGES OF THE END-CUT.
One trouble with reamers, however, is that the teeth neces-
sarily cut on their side edges instead of on their ends, and the
whole effect of any uuevenness in the hole is to crowd the reamer
to one side. The same condition exists to a less extent with a
flat or twist-drill where the cutting-edges are at an angle with the
centre line, and the resultant of any unusual pressure is felt
partly as a side-thrust and partly as an end-thrust. Now, by
making a drill to cut squarely on its end, and but very little or
not at all on its sides, the side-thrust is mostly done away with.
In Fig. 274 is a boring-tool, with a single cutting-edge, which
cuts on its end and is capable of drilling a true hole in solid
metal. It was illustrated in the August, 1896, number of "Ma-
chinery." 1 It consists of a round, tool-steel bar, with one end
flattened and ground to form a cutting-edge, as shown. It is de-
signed to be held in the tool-post of the lathe, in a position per-
FiG. 274.
pendicular to the face-plate. The inner edge, or corner of the
cutting-edge, should be slightly rounded, to help support the
cutter and prevent chattering, and the width A of the cutting-
edge should be from ■£%- to -fa -inch less than the radius of the
hole to be drilled.
INTERCHANGEABLE MANUFACTURING.
249
DKILLING DEEP HOLES BY THE PBATT &
WHITNEY METHOD.
A highly satisfactory drill for use in drilling deep holes is
one brought out by the Pratt & Whitney Co. , principally for use
in connection with their gun-barrel drilling-machines. The tool
in question is a development of the old D or "hognose" drill,
x
FIG. 275.
which has one cutting-lip only. It is carefully ground on the
outside and is supplied with an oil -duct through which oil at
high pressure may be brought direct to cutting-edge. Referring
to Fig. 275, A is the cutting-edge, B the oil-duct, C the chip-
groove.
In the milling the latter groove is brought directly to the
centre, so that in this respect the drill is very free-cutting as
compared with the ordinary two-lip twist-drill, which has a cen-
tral web. In the end view the shape of the chip-groove is clearly
indicated. The cutting-edge A is radial and the bottom of the
groove touches the centre line x y.
In sharpening the drill the high point, or part first entering
the work, is not in the centre, as is usually the case in drills, but
as per Fig. 275, in which i> is a cross-section of work being
drilled and E the high point of drill. Grinding the drill in this
manner is one of the reasons for its running true or straight, the
teat F on the work acting as a support to the drill, which, owing
to its periphery being partly relieved, would have a tendency to
travel in a curve away from its cutting-side. The piece being
drilled is run at very high speed, the periphery speed at the outer
diameter of the hole running as high as 130 feet per minute on
machine steel. The feed, however, is quite fine.
250
TOOL-MAKING AND
These tools are made of high-grade steel and left very hard,
so that the fine feed has little tendency to glaze the cutting-edge.
In practice, the piece being drilled is held and revolved at
one end by a suitable chuck on the live spindle of the machine,
while the other end, which should be turned perfectly true, runs
in a stationary bushing having at its outer end a hole of the di-
ns. 276.
ameter of the drill. The drill enters the work through the bush-
ing and is thus started perfectly true. See Fig. 276, in which A
represents the chuck, B the work, C the bushing, D the support
for holding the bushing, E the drill.
Through the oil -duct of the drill oil is forced at a pressure
varying with its diameter from one hundred and fifty to two
hundred pounds per square inch. After passing the cutting-
edge the oil returns to the reservoir by the chip-groove C, Fig.
275, forcing chips along in its travel. In drills of large diame-
ter, especially when working on tough, stringy material, the cut-
ting-edge is usually ground so as to produce a number of shav-
FiG. 277.
ings, instead of one the full width of the cutting-lip, so that no
trouble is experienced in getting the chips out of the way. The
oil, of course, is used over and over again, and with a large res-
ervoir will be kept quite cool.
The drill is made up of the drill-tip and shank, the tip vary-
ing in length from four inches to eight inches, while the length
of shank is determined by the depth of hole that is to be drilled.
Fig. 277 will clearly illustrate the construction of a small, com-
plete drill, A being the tip, C the shank, and D the oil-duct.
INTERCHANGEABLE MANUFACTURING.
251
The shanks on small drills are made from steel tubing rolled as
per cross-section a a. The tip is carefully fitted and soldered to
the shank, which, it should be noted, is a little smaller in diameter
than the tip. The shank, with oil under pressure, is very stiff.
The relief or clearance to the cutting-edge of the drill, the
amount of "high-point" of the drill should be off centre, and
the number of rings on the end of the drill depend entirely upon
the material that is to be drilled. For instance, on very soft
Fig. 278
stock the supporting rest should be more substantial than on
hard spindle or gun steel, so that it is evident that on soft stock
the high point should be off centre, or much nearer to the outer
diameter than on hard stock.
Fig. 278 is a sketch of a 3-inch drill, and the reader will ob-
tain a very clear idea from same of the appearance of the tool
we have described. This figure illustrates a drill ground on the
end so as to produce several shavings.
BOEING HOLLOW SPINDLES WITH A HOLLOW
DEILL.
* In boring the inner tubes of steel guns of large calibre, it
has long been the practice to bore them with a hollow drill,
* " American Machinist. "
252
TOOL-MAKING AND
which
moved
leaves a core in the centre, so that the entire metal re-
is not converted into chips, but only what might be
termed a shell of it, the outside diameter of this
shell being practically equal to the bore and the
inner diameter being enough smaller to leave a
reasonable thickness for the drill.
At the works of Schneider & Co. , at Cruesot,
France, gun tubes are bored ou this plan, and it is
likely that the same plan is followed at Krupp's.
It has not, so far as known, however, been ap-
plied to the boring of hollow spindles for ma-
chine tools until very recently, when it was found
in use in the shops of Mr. Dietz in Cincinnati,
Mr. Dietz 's shop being operated in connection
with that of the Lodge & Shipley Machine Tool
Company, and upon certain sizes of their lathes.
Mr. Dietz uses in a boring- machine of the usual
type a drill made like the sketch, Fig. 279,
which is a hollow cylinder with a T 3 T -inch pipe
for lubrication, and the cutter is located as shown,
inclined somewhat to the axial plane in order
to give a top rake and with the edge gashed in
order to break up the chips and allow them
to be washed out through the groove from one
end, and then reversed and the boring completed
from the other end. This leaves a core of metal
which, as it is worth a considerable amount, is
well worth saving, to say nothing of the fact
that the boring is more easily done and with less
strain upon the machine by this plan than where
all the metal is reduced to chips.
DEILL NOTES.
Fig. 279.
As a rule, the cutting-edges of twist-drills
are formed with a cutter of correct form to pro-
duce a radial line of cutting-edge ; thus a different form of cutter
is required for milling the flutes of straight- flute drills.
INTERCHANGEABLE MANUFACTURING. 253
Drills are generally made of 0.002-inch or 0. 993-inch taper
per foot for clearance, and have the major part of land on the
periphery ground away for the same purpose, about 0.003-inch
on a side.
Drills for brass should be made with straight flutes ; those for
cast-iron and tool steel should in those cases have spiral flutes at
an angle of about sixteen degrees ; soft steel, twenty-two degrees.
Chucking-drills, for use on cored holes, or as followers of
solid twist-drills, are quite often provided with from three to
eight flutes ; the latter, on large work, are very efficient. Care
should be taken, in grinding, to insure all teeth cutting simulta-
neously. These tools are made of solid, shell, and inserted type.
The inserted type are preferable for straight flutes over 2f
inches, and for angular flutes over 4 inches, on account of cost.
For drilling a large hole in a spindle the latter should be sup-
ported in a back rest, and the drill entered through a drill-bush-
ing to start perfectly true. Then, by using a drill with one cut-
ting-edge and ground on the outside, a long, straight hole may
be readily produced. An ordinary twist-drill will do practically
the same if the centre is made female, the only objection being
that this form is much more difficult to grind.
CIRCULAR FORMING-TOOLS.
Circular forming-tools for machine steel and cast- iron should
have a generous amount of clearance.
Care must be taken on particular forms, when forming-cut-
ters are not on centre, that they are formed with this point taken
into consideration.
Circular threading-tools for inside threading must be much
smaller than the work ; about one-third is the proper practice.
Care should be exercised to use a correct angle of chaser.
PLAIN FORMING-TOOLS.
Plain forming tools should have a clearance of from six and
one-half to ten degrees.
Rake : Machine steel, eight to thirteen degrees.
Rake: Tool-steel, medium, six to nine degrees.
Rake: Brass, none.
254 TOOL-MAKING AND
The clearance on tools for brass is quite often stoned off its
cutting-edge to prevent "biting in" (due to ease in cutting) and
then chattering (due to great thickness of chip and consequent
difficulty in severing). The "stoning off" also tends to act as a
support for the cutter.
FACING.
For steel and cast-iron, cutters with from six to twelve de-
grees rake cut very freely, The clearance should be from three
and one-third to ten degrees ; when there is any tendency to chat-
ter, the cutting-edge should be oil-stoned on clearance-face suffi-
ciently to prevent " biting in." On very broad work it often
becomes necessary to make cutters without any rake or angle,
but allow scraping, to prevent chatter.
In practice it is found advantageous to place cutter ahead of
centre, exposing a larger cutting-edge to work, giving thinner
chip.
In multiple or inserted cutter-heads, it is well to unevenly
space the cutters ; as a precaution against chattering, have the
cutters "staggered."
Use machines with large bearings, and with chucks close to
same, for good results.
COTXNTEEBOBING.
For cast-iron and steel, counterbores are generally made
with ten to sixteen-degree angles, i.e., spiral; for brass they are
cut straight. Clearance is from five to ten degrees. On brass,
"stone " the clearance -edge to prevent chattering.
Counterbores internally lubricated are recommended for steel
for use to depth of one-half of the diameter or more.
Angle- clearance on all tools must be more than spiral gener-
ated by feed at smallest diameter of cutting-point, plus suffi-
cient to be really forced to work (about three degrees).
COUNTEBBOBES.
As a rule counterbores should be made with a hole chucked
at the cuttiug-end several sizes below the hole that is to guide
the counterboring tool.
INTERCHANGEABLE MANUFACTURING. 255
Then the guides used at the cutting-end may be of many sizes,
and fit many -sized holes. The shanks of the guides, or the ends
that enter the holes, should be all of one size, and should be fitted
to force lightly in so they may be readily removed from the body
of the tool and others inserted in their place to fit a hole of an-
other size. The upper portions of these guides are turned up to
a shoulder, and to about half an inch or less from the outside, or
according to the size of the tool. This also gives the workman a
better chance to file the cutting-end or lips to a perfect and true
edge. The lips on their sides may be an inch or less in length,
according to their diameter, and they should be milled out
diagonally in order to give a shaving cut and also a better clear-
ance for the chips.
BEAMING HOLES IN THE TUBBET-LATHE.
To ream holes uniform in diameter in the turret-lathe or
monitor, it is necessary that there shall be in all cases an equal
amount of metal for the reamer to remove. To insure this con-
dition two reamers, a rougher, and a finisher should be used.
The hole, first, if cored, should be bored by a single or a double
edge boring-tool to insure a hole comparatively true.
BEAMING HOLES IN THIN DISKS.
For reaming holes in thin disks a reamer of the "rose type "
should be used, as it will be self-supporting, and the possibility
of enlarging the hole by its weight will be obviated.
MACHINE-BEAMING WITH A "FLOATING" BEAMEB.
Very often, when machine-reaming, the finishing reamer is
supported loosely in its holder, and allowed to find its own centre
by following the true or concentric
J ° BUSHING /PIN
hole left by the preceding tools. \ '^JHI «„„„„.
This is usually done by having a (^ _ ' I j
" floating " reamer with a pin entered ^— — J*-— '
to L Fig. 280.
through the holder and the reamer
in the back end, the hole in the reamer being made larger than
the pin, thus allowing the reamer to find its own centre. The
construction of a reamer of this type is shown in Fig. 280.
256 TOOL-MAKING AND
BEAMING TAPER HOLES IN CAST-IRON.
For reaming taper holes in cast-iron machine parts in the
turret-lathe, particularly those parts from which large amounts
of stock are to be removed, a reamer of the construction shown
in Fig. 281 should be used. As will be seen, this reamer has
only three blades. The flutes in a reamer of this kind should
be Cut as deep as the diameter of the stock will allow, and the
blade should be given very little clearance. The clearance that
is necessary may be provided by grinding the blades convex, as
shown, instead of flat or hollow, as is usually done. When a
considerable amount of stock is to be removed, a reamer of this
type will work very well. The preliminary work re-
quired, with regard to the other boring-tools, before
the one shown should be used, consists of boring a
hole to the right size for the small end of the reamer,
Fir ^81
after which the three- blade finishing reamer may
be used to finish an irregular surface from three to six inches
long, feeding the reamer in rapidly without danger of catching,
chattering, or roughing up. In one large machine-manufactur-
ing establishment thousands of holes are finished every day with
reamers of this type, attaining the best results in the shortest
time with the least trouble.
TAPER-REAMING IN THE SCREW-MACHINE.
To do taper-reaming in the screw-machine, use reamers taper-
ing from 2 J inches per foot upward, and the best results will be
accomplished. For very accurate work the reamers will give
better satisfaction if made with left-hand spiral flutes.
For want of proper grinding facilities, however, this is not
done in many shops.
To ream slightly tapering holes of small diameters, the reamer
should always be made with the teeth "staggered" in spacing,
and each flute a left-hand spiral of different pitch.
Very often roughing-, taper-, and forming -reamers for steel
are finished with an undercut. They remove material very
rapidly.
INTERCHANGEABLE MANUFACTURING. 257
EEAMEES FOE BBOJECTILES.
In the production of projectiles, forming-, taper-, and curv-
ing reamers are used. For this work roughing-reamers should
be finished with a left-hand spiral thread nicked around, while
the finishing ones should be finished straight. The finishing of
taper-reamers. with left-hand spiral flutes for this work prevents
their being drawn in while cutting.
TAFEE OF BOSE-BEAMEBS.
Eose-reamers should be given taper for clearance, about
0.003-iuch to the foot will be enough. This will prevent them
from roughing up the hole and allow of finishing holes straight
and correct in diameters.
CENTEE-EEAMEES.
Centre -reamers should be finished to an angle of sixty de-
grees, and the work centres of all machines to the same. The
centres should be hardened and ground in their machines by
means of a good tool-post grinder to gauge, as it is impossible to
do good work on defective centres.
EEAMEES FOE BABBIT.
For reaming babbit, the reamer may be of the usual form,
except that the edges of the blades should be ground taper for
about ^-inch from the end. Sometimes reamers for such mate-
rial are finished with left-hand spiral flutes, which contributes
to finishing a smooth hole free from lines and rings.
BEAMING HOLES IN TWO KINDS OF METAL.
Not infrequently it is necessary to bore a hole in a part which
is made up of two kinds of metal, such as brass and cast-iron,
for instance. This is a rather difficult thing to accomplish suc-
cessfully, as the hole will usually be larger in the softer side of
the metal than in the harder. However, by using a reamer with
17
258
TOOL-MAKING AND
a cutter-face of the construction shown in Fig. 282, and cutting
an uneven number of staggered flutes in it, satisfactory results
will be attained. Have the angle of the cutter-
face about ten degrees. In using this reamer,
first bore the hole with the usual type of boring-
tools until it is a size slightly below that re-
quired, then chamfer the edges of the hole on
the bard side and feed in the reamer, lubricating generously
with oil, and always see that the hard side. of the work is out.
Fig. 283.
MACHINE-REAMING OF BRASS PARTS.
For the machine-reaming of brass parts some make their
reamers slightly over size, but this is wrong. Instead, a reamer
for brass should be ground in much the same manner as a turn-
ing-tool for brass should be — that is, in place of a radial line in
the centre, as in most other reamers, the cutting-edges should be
thrown off from the centre at an angle
of about twenty degrees out of the radial
line, as per Fig. 283. For the same rea-
son, in turning brass, if the tool is ground
straight and set central with the work,
chattering is bound to occur. If, on the
contrary, the tool is reground on top to
an angle as described above, running toward the underside of
the blade, chattering will be obviated and the tool will cut freely.
Always keep the cutting-edges of reamers for brass as sharp
as possible by "stoning," because as soon as the cutting-edges
become slightly dulled they will bind and scream.
Fig. 283.
SQUARE REAMERS AND EXPANSION REAMERS.
Fine finishing of holes in brass may be done with the square
reamer or "scraper." Expansion reamers also possess many
good points, but few, if any, can be expanded and adjusted for
sizing without the cutting-edges requiring to be ground before
the tool can be used. However, there are some in which the
blades will expand equally. Even if it is necessary to grind the
expansion reamers when changing an adjustment, there is econ-
INTERCHANGEABLE MANUFACTURING. 259
oiny in their use when compared with the cost of a new solid
reamer, especially when they are used for holes of large diame-
ters. A long hole may be reamed straight by pulling back
slightly after the reamer has commenced to cut.
BEAMING SMALL HOLES.
For machining very small holes in steel and cast-iron, ream-
ers should be ground straight, while for brass and copper they
should be ground slightly back, tapering in order to eliminate
the possibility of roughing up the holes.
Always remember that on reamers for steel and cast-iron the
teeth should be on centre, while for brass, copper, and similar
metals they should be at an angle of twenty degrees off the radial
line.
Speeds for machine-reaming should usually range from 20 to
25 per cent, lower than turning and drilling-speeds.
"HOME-MADE" EEAMEES.
There are in a great many shops numbers of "home-made"
reamers in the possession of the men, made at various times by
the mechanics, without due regard to their proper construction.
Eeamers of this kind should never be used for fine work, as they
are usually defective. For instance, the flutes are too shallow
and spaced too close, and often they are
spaced evenly instead of being staggered,
or they have an even number of teeth, all
of which is wrong. When a reamer is FlG 2 8i.
evenly spaced it will chatter as soon as the
cutting-edges fall into the notches left by the preceding one. A
common fault with "home-made" reamers is that they are given
too much clearance, thus making chattering inevitable.
HAND-BEAMING.
In hand-reaming never leave more than 0.003 of stock to be
removed, no matter what the material may be. On the contrary,
for machine-reaming, not less than -^ and often T ^ should be left;
2G0 TOOL-MAKING
using reamers with much coarser blades than the usual commer-
cial ones, and formed so that they can be ground on the points.
Hand-reamers for use in boiler, bridge work, etc. , should be
of the construction shown in Fig. 284, as they will work better
than the usual half-round kind.
INCREASING THE SIZE OF A REAMER WHEN
WORN.
To increase a reamer to size when worn, burnish the face of
each tooth with a hardened burnisher, which can be made from a
three-cornered file nicely polished on the corners. This will in-
crease the size from two to ten thousandths in diameter. Then
hone back to the required size.
To make a tap or reamer cut larger than itself, put a piece
of waste in one flute, enough to crowd it over, and cut out on one
side only. In larger sizes (l|-inch or over) put a strip of tin on
one side and let it follow the tap through.
CHAPTER XVIII.
Broaches and Broaching.
THE OPERATION OF BROACHING.
The operation of broaching may be classed under the head
of punches and dies, as it is analogous with press-work. In
reality the broach is a punch, the cored or drilled holes in the
work to be machined by it acting as a die and guide for same.
The operation of broaching has had great develop-
ment during the last decade, special machines and
forms of tools having been designed to further the
use of this interesting and labor-saving process for
the finishing of work which it was formerly thought
to be impossible to finish by such means.
The broach as a tool is usually used for finishing
holes which have been previously either punched,
cored, drilled, or bored in metal, the shape of which
may be round, square, or any irregular shape de-
sired. Although the broach can be used to advan-
tage for the finishing of holes by setting it under
an ordinary power-press, an arbor-press, or a foot-
or screw-press, the operation can be best accom-
plished in a press specially designed for the pur-
pose of broaching. A press of this sort has usu-
ally an adjustable stroke of from 1^ to 12 inches.
In Fig. 285 we show a sketch of a broach used
for finishing a cored hole in a rough casting. The
tool is 3 x 1 inches, and 9 inches in length. In this tool the
teeth are very coarse at the lower end, being intended for re-
moving the bulk of the stock until the centre of the broach is
reached, when the teeth are sheared in the opposite direction,
thus breaking the chip off. The teeth in the broach then de-
crease in size until near the upper end, when they are left the
261
Fig. 285.
262 TOOL-MAKING AND
one size for about two inches of the remaining length, thus form-
ing a "sizer" which shaves the hole to a standard size all the
way through.
In forcing a broach through a hole it may be best driven by
a "V" brock, which should- be secured in the press-ram in much
the same manner as a punch would be. Thus when the press-
ram descends the broach will find its own centre ; while the lia-
bility of breaking or bending the broach or producing an im-
perfect hole will be obviated.
In order to broach holes of considerable length in a press
with a short stroke, the work may be satisfactorily accomplished
by using a successive number of blocks. First insert the broach
in the hole and then drive it down into the same for the full
length of the press-stroke. Kext, insert a block of the same
thickness as the length of the stroke between the ram-face and
the broach-end, and then force the broach in a further distance ;
repeating the operation and using larger blocks until the desired
length of drive has been obtained. By this method it may be
well to state that the results attained will not equal the work
performed on a continuous stroke-press, as the stopping of the
broach when partly through the work allows the metal to settle
into the broach teeth, thus increasing the tendency to bend and
break.
To-day there are on the market any number of machines
which have been specially designed for broaching. A number
of these machines perform the operation by pulling the broach
through the hole instead of forcing it through.
AN INTEEESTING JOB OF BBOACHING.
Broaching is very interesting work. For some work the best
and only way to make a broach is in one piece; while for other
work long experience has taught that it is the wrong way. To
do the job shown in the sketch, Fig. 286, with one broach would
require a long one, and that would cause trouble; for a broach
of sufficient length for this work is difficult to turn and mill,
and to harden and draw, owing to the keyway on one side which
will cause it to spring in hardening ; it would be an advantage if
it were grooved on opposite sides.
INTERCHANGEABLE MANUFACTURING.
263
The hole in the piece shown in Fig. 286 is broached from |-
to |i-inch — and a key T ] ¥ -inch high formed— and is afterward
drifted to i-i-inch at the bottom and f -inch at the top ; the thick-
ness of the piece is finch. Over 250,000 pieces have been
made with the broaches as shown, and the loss in broaches and
pieces was nothing compared with the loss when using the long
broaches first made.
The stock for this job was a special tough tool steel. The
broaches are shown in Figs. 287 to 291 ; they were four inches
long and of the diameter given. Each was tapered at one end
FIG. 286.
r -late C, Fig. 293. To the plate was secured
two rods, which had a vertical movement in plate B, light
springs keeping plate C away from the punch. An important
feature is the hole H, which received the end of the broach and
prevented its being placed in the wrong position, as each broach
had to follow exact, owing to the keyway.
A clearance (shown at D) on each broach served to guide an
end of the broach while entering. After the first broach was
entered and forced into the work by the press, the upper end
MamvMMmr — t <;Mm
PUNCH PRESS PLATE_
FIG. 292.
projected above the work to receive the second broach, which
was in turn punched through, being followed by broach No. 3,
and the latter by No. 4. If teeth were cut the full length of the
last broach, it would stick in the work. To overcome this it was
cleared at the end, as shown, so that when punched down to the
end of the stroke the broach would fall through. The work in
making broaches of this length is simple, as they are easy to
turn, harden, draw, and grind.
In punch A a hardened -steel plate, D, was inserted, as at this
point any wear would cause the broach to twist and spoil the
key. This is made a driving fit, and can be replaced at any
INTERCHANGEABLE MANUFA CTUBING.
265
time. The finished hole, Fig. 286, was drifted cold ; and owing
to the quality of the stock was a neat piece of work. Figs. 293
and 294 show the drift and the punch-press fixtures. The punch
^A
Fig. 293.
Fig. 294.
for putting in the drift had a steel insert, the same as D in A.
It is very important in making broaches that the stock be thor-
oughly annealed, and when broaching use nothing but the very
best of oil.
SOME POINTS ABOUT BEOACHES AND BROACHING.
In order to secure good results in broaching the bottom of
the tool used should be hollowed out somewhat, so that a nice
clean chip will be cut from the inside of the hole, and so that the
tendency to dodge to one side when places in which the cored
hole is rough or crooked are encountered will be obviated. The
stripper for the work should be arranged so as to pull off square.
Otherwise, if the hole is a long one, it will be spoiled when the
broach is pulled out.
The special presses provided for broaching are usually back-
geared and very powerful. It is not well to speed the press too
fast. In all cases use oil as a lubricant. When the amount of
266
TOOL-MAKING AND
stock to be removed is considerable, it will be necessary to do
the work in two operations ; too heavy a cut having a tendency
to make the hole rough. Socket-wrenches or similar fits are
easily made in this way. If the cuts are made light enough, it
is possible to broach cast-iron in this way, using for this purpose
several punches or broaches of different sizes. Such punches
should be slightly larger at the cutting end, and for the finishing
cut or last operation— if clear through the piece — should work
into a die or the tool will break off or tear away the lower edge
of the work. The temper should be a trifle harder than that
given to ordinary punches and dies. A in Fig. 295 shows a side
view of a broach which was made for cutting out the holes in
three cast-steel flanges for a steamboat. The holes had been
cored out of a f -inch bolt instead of a f-inch ; hence the necessity
for enlarging them. The broach was made with six steps, as
6__ ^4821
% SQUARE STEEL
„
/
\
6
\
/
Fig. 29.5.
shown at A, and with the steps numbered at B. Step 1 acts as
a pilot and to scrape out the sand ; step 2 cuts on four sides some-
what, as shown at C, step 3 cuts the hole slightly larger in the
same manner ; the next three steps cut out the corners, as shown
in 4, 5, and 6.
There were ninety holes in all, one-half of which were through
took about three hours to broach them out, driving the broach
with a sledge, as no press was at hand. The operation of mak-
ing the tool took about one and one-half hours on the milling-
machine, using an end -mill.
INTERCHANGEABLE MANUFACTURING. 267
BEO ACHING: ITS EELATION TO SHEET-METAL
WOEK.
Oberlin Smith, in bis "Press Working of Metals," bas given
ns tbe following in regard to the relation of the word "broach-
ing " to sheet-metal work :
"... The word ' broaching ' has here a very different
meaning from that given it by the machinist, who applies it to
the process of forcing a .piece of male work through a lower cut-
ting-die, or pushing a cutting-punch through a hole in female
work, thereby shaving it to a given size, and really performing
an operation analogous to planing or slotting. In cases where
he uses male or female broaching-cutters having a series of teeth
following each other, and each taking off its own chip, his work
more nearly resembles milling. In relation to sheet metals the
word broaching means smashing the work thinner by forcing it
through a space between the punch and die, as in some kinds of
tube-drawing, which again is the same as wire-drawing, if we
imagine the mandrel to be a part of the tube. In the case in
question a reduction of diameter is being made at the same time
as the thinning of the metal is taking place. This is much prac-
tised in cartridge -drawing, especially where it is desirable to
keep the end or bottom of the work of the original thickness.
When done, the bottom remains of as much greater thickness
than the sides as happens to be required and as has been arranged
for in choosing the thickness of the sheet. In small work of this
kind the use of a blank-holder, or upper die, is abandoned after
the first one or two draws, as the metal is reduced so little in
diameter in proportion to its thickness that the wrinkles have no
chance to form. Even if incipient wrinkles do form they are
quickly crushed out again as the metal is squeezed somewhat
thinner. In this, as in all drawing, however, the wrinkles must
never be allowed to get big enough to fold over upon one another. "
CHAPTER XIX.
Shop Use of Micrometer-Calipers and the Height-
Gauge.
MICROMETEE-CALIPEES.
In the accurate production of duplicate parts as carried on
to-day in the economic manufacture of machinery, tools, punches
and dies, and instruments of precision, accurate gauges are de-
manded. For years the average machine-shop got along with
templets and gauges of sheet steel, so-called "limit-gauges," of
doubtful accuracy and of little value, as they were carelessly
made and used with indifference. However, we are pleased to
say, this state of affairs has passed away; and the increased use
of the micrometer-caliper has enriched the scrap piles of many
shops with collections of "snap" and "limit" gauges, "temp-
lets " and " reference " disks ; has increased the economic produc-
tion of the shops, and made the workmen more skilful.
To produce accurate work the skilled machinist or tool-maker
of to-day demands as a first requisite a means of measuring his
work during the process of machining it to the required size and
shape ; and this requirement is filled when the workman is sup-
plied with a micrometer caliper and the feed-screws of the ma-
chine which he operates are fitted with graduated disks. Of course
it must not be inferred from this that braius are not required
along with these gauges ; or that an indifferent or careless work-
man will instantly become a skilled mechanic upon being supplied
with a micrometer. However, the use of the micrometer will
improve the poorest workman ; as instead of guessing he will
measure ; he will use his eyes and think ; thus a consequent im-
provement will take place.
Among shop managers, superintendents, and foremen, the
most common objection raised against the general shop use of
micrometers is that they are too light, and are liable to get out
268
INTERCHANGEABLE MANUFACTURING. 269
of order when used by all classes of help. Now, while this may
occur, there is hardly any excuse for it ; any man that is trusted
with and is capable of turning out' accurate work can be safely
trusted to use a micrometer correctly. To be sure it makes a
great difference how the tool is handled. It all depends upon the
workman's sense of touch. The machinist, as a rule, wants in-
formation as to how much more has to come off after he has
taken a cut, and so he sometimes forces the gauge in the hope of
determining by the sense of touch how much remains to come
off. This sense of touch differs in mechanics very much. In
some it amounts to a considerable exertion of their strength;
these are the one who spoil the gauges.
With the micrometer there is no excuse for the use of strength ;
it is an adjustable gauge aud the machinist knows by reading it
when the work has been reduced to the size desired. He knows
also that he may run the screw back at intervals and determine
the amounts remaining to come off ; he may also determine the
size at the start ; and for sizing a number of pieces he may lock
it and use it in the same manner as he would a snap -gauge. In
the use of the micrometer the mechanic has to use his eyes and
brains more, and his strength becomes an ineffective factor in
the attainment of the results.
It is very easy to teach bright apprentices and operators how
to use micrometers ; in fact, the reading of them to the one-thou-
sandth of an inch is very simple ; while their reading to one-ten-
thousandth of an inch can be learned after a little thought and
practice. The ease with which workmen in general learn to read
and use these gauges can be inferred from the fact that there are
any number of small shops — in the East at least — to my knowl-
edge, in which accurate work is turned out, where nothing in the
way of gauges is used but micrometers. As this is successfully
done on a small scale, I can see no reason why the installation
of the system on a large scale should present difficulties.
In all shops in which micrometers are used in place of the
obsolete gauges, or in shops where they are about to be used, a
good set of B. & S. test pieces, either end-measures or disks,
should be provided ; also a man should be detailed to take care
of the adjustments of all micrometers in the shop ; someone who
270
TOOL-MAKING AND
is skilled iu such work and who has cultivated a delicate sense of
touch. In shops where the work done is of great accuracy and
only the minimum limit of error is allowable, two sets of test
measures should be provided ; one set to be for general use and
the other for occasional reference only. The new micrometers
should be given to the most skilled men for use on the finest
work only ; while those micrometers that have become worn, or
are to a certain extent inaccurate, should be used on work in
which a greater limit of error is allowable. Above all, never
use generally calipers graduated to ten-thousandths, where fine
measurements are not necessary, as in an instrument of the pre-
cision of this class a wear is preceptible and important which
would be of comparatively slight consequence in a caliper that is
graduated to be read only in thousandths.
BEADING MICROMETER-CALIPERS TO TEN-
THOUSANDTHS OF AN INCH.
While the ordinary reading of micrometers is pretty gener-
ally understood — i.e., reading to thousandths of an inch — the
reading of them to ten-thousandths is not. For the benefit of
those who do not understand this I explain in the following
how to do it.
In Fig. 296 a 1-inch B. & S. micrometer-caliper graduated to
read to ten-thousandths of an inch is illustrated. The readings
nTjTTnTJ
THIMBLE
Fig. 296.
in ten-thousandths are obtained by means of a veriner or series
of divisions on the barrel of the caliper on the side shown in the
cut. These divisions are ten in number, and occupy the same
INTERCHANGEABLE MANUFACTURING. 271
space as nine divisions on the thimble. Accordingly, when a
line on the thimble coincides with the first line of the veriner,
the next two lines to the right differ from each other one-tenth of
the length of a division on the thimble ; the next two lines differ
by two-tenths, etc. Note the left hand cut of graduations on the
barrel and thimble in Fig. 296.
When the caliper is opened, the thimble is turned to the left,
and when a division passes a fixed point on the barrel, it shows
the caliper has been opened one-thousandth of an inch. Hence,
when the thimble is turned so that a line on the thimble coin-
cides with the second line (end of first division) of the veriner,
the thimble has moved one-tenth of one-thousandth, or one ten-
thousandth of an inch. When a line on the thimble coincides
with the third line (end of second division) on the veriner, the
caliper has been opened two ten-thousandths of an inch, etc.
Note the right hand cut of graduations, where the line on the
thimble coincides with the fourth line (end of third division)
and the reading is three one-thousandths of an inch.
To read the caliper, note the thousandths as usual, then count
the number of divisions on the veriner, commencing at the left,
until a line is reached with which a line on the thimble coincides.
If the second line, add one ten -thousandth, if the third, two ten-
thousandths, etc.
SPECIAL USES OF MICEOMETEE-OALIPEES.
Besides the uses for which the micrometer was primarily de-
signed and is generally used, there are any number of special
uses to which the caliper can be put : In the following I enu-
merate and describe a number which will no doubt be the means
of suggesting many others.
In order to determine whether the dead centre and the live
centre of a lathe are in line : First, set the centres as near as pos-
sible by eye ; then carefully centre a piece of stock about six
inches long; place it on the centre and turn one end for a dis-
tance of about one-half inch, using a sharp -edged tool so as to
get a sm ooth surface. Then reverse the stock so that the turned
end will be at the live centre. Next, turn the other end to ex-
272
TOOL-MAKING AND
actly the same diameter, using the micrometer to gauge it. IsTow
clamp the micrometer to the cross-slide of the lathe, so that the
end of the barrel or ratchet-stop will rest against the work, as
shown in Fig. 297. You can now set your centres accurately by
Fig. 297.
running the barrel out against the nearest end, noting the read-
ing and running back the barrel, running the carriage up to the
other end and repeating the operation. A few trials and adjust-
ments of the tail-centre and both centres will be set dead in line.
In order to test the lathe to see whether the centres are the
same height from the ways, the same method can be adopted by
Shcft
Fig. 298.
using the micrometer backward, from the top down, or from the
bottom up, as shown in Fig. 298.
To line up the centres on a grinder so as to get them dead in
line the micrometer can be used by fastening the caliper between
the collars of the spindle where the emery-wheel is usually located,
in the manner shown in Fig. 299, and by blocking up the spin-
INTERCHANGEABLE MANUFACTURING.
273
die in the most convenient manner. In using the micrometer in
this manner, however, always remember that all round or circu-
lar work will have an error twice that evidenced by the gauge.
Jfimeri/ Jfflteet
FIG. 299.
That is to say, if the centres show only 0. 0012 by the microm-
eter in the test, they will shown an error of 0.0024 on the
work. On straight surface work the test will show the actual
error*
It will be at once obvious to the practical reader that this sys-
tem of testing can be applied to almost any machine in the shop.
On the planer, miller, shaper, or precision-lathe it will be found
all that can be desired in detecting errors in the platen, vise, or
fixtures; while when utilized in the lining up of a job with a
finished surface, it is as good as a surface-tester and lends itself
much more readily to the work in hand.
In fact, this system can be almost uni-
versally applied where accurate work
from machines is absolutely required.
The micrometer-caliper can also be
used as an inside caliper in any hole in
which it will go in with ease. This is
shown in Fig. 300, the caliper being
used to gauge the inside of a large
cutting-die when grinding it to the finish size. To use the gauge
in this manner it is only necessary for one to learn to read the
18
Fig. 300.
274 TOOL-MAKING AND
graduations backwards; then no difficulty will be experienced in
using it as an inside micrometer.
In all shops where micrometers are used generally it will
faciliate their use and expedite the production of accurate work
by having the feed-screws of all machines fitted with graduated
dials ; and if the micrometers in use are graduated to read in
thousandths, by having the dials to read the same.
The universal use of micrometer-calipers for regular machine-
shop gauges is not far distant, as it will not be long before the
chief and perhaps the only interdiction to their extensive use —
their cost — will be overcome. That the demand is growing is
evidenced by the fact that one concern in the East manufactures
a line measuring from six to twelve inches for use on the larger
classes of interchangeable machine work.
THE HEIGHT-GAUGE AND ITS USE.
While the micrometer occupies first place among the small
precision tools of the universal shop, there is another tool which
follows it a close second. I refer to the height gauge, Fig. 301 ;
a tool that although it is used quite generally among tool-maskers,
is comparatively unknown outside of them. If more w r ere known
of the great utility of this handy, accurate, reliable, and almost
indispensable tool, its use would become common in all shops
where accurate work is done. By many the height-gauge is
thought to be merely an accessary to the tool-maker's kit, and of
no use except in verifying measurements ; when, on the contrary,
it can be used for a thousand and one jobs in the attainment of
results with ease which would otherwise be almost impossible of
attainment were other means used. In accurate work, especially,
by means of the height-gauge, jobs that appear to present insur-
mountable difficulties are accomplished with ease.
In order that the utility and value of this accurate tool may
become better understood I will present a few examples of its use :
By far the most usual and common method of striking or
scribing a line on a piece of work is with the surface-gauge ; set-
ting the scriber to some graduation on a scale. This method,
however, is not to be compared with the height-gauge and its
INTERCHANGEABLE MANUFA CTURING.
275
scriber in point of economy of time, labor, and worry ; for the
reason that the height-gauge may be set almost instantly and ac-
curately when one is familiar with it, and a line may be scribed
with it at once with the assurance positive that it is in exactly the
place that one wishes it to be. With the surface-gauge the
scriber must be raised and lowered many times before the cor-
rect (?) height is obtained ; even then the final setting is a guess.
*t-=
Fig. 301.
For example second, let us say that it is necessary to locate
eight holes in a circular finished casting as per Fig. 303 ; the
holes to form the corners of two squares, one within the other,
with the four holes of each equidistant from the centre of the
casting. The way to accomplish the desired results accurately
with ease will be to take an angle-plate like 302, true it on three
of its sides, and then clamp the disk on its face A. The exact
diameter of the casting in which the holes are to be located is
found first ; then the height of its lower edge from the surface-
plate on which the angle-plate rests; then, by means of the
276
TOOL-MAKING AND
veriner on the height-gauge and the scriber which comes with it,
we scribe two lines the required distance apart, equally above
Fig. 302.
and below the centre, for the outside square, then two more lines
for the inside square. Next, without removing the casting from
Centers
Centers
Centers
Center**
Fig. 303.
the angle-plate, we turn the plate on to face B and then scribe
four lines in a like manner, thus finishing the two squares. All
INTERCHANGEABLE MANUFA CTUBING.
277
is now ready to drill and tap the eight holes approximately cor-
rect, where the lines intersect, for the "button" screws, which
we use to locate the "buttons" true for boring the holes. From
this example it will be at once obvious that holes may be located
in a like manner on any given surface, providing that care has
been previously taken to have the surfaces from which the neces-
sary measurements are taken perfectly true and square with each
other.
For the third example, we will take the block shown in Fig.
304, which has a hole at G and in which it is desired to drill two-
more holes centrally with the first one way, but at angles with
it the other, as shown by the dotted lines. We first bolt the
angle-plate on the table of the miller, square with the sp indie,
.Aticfular Tfo/es
.. . ..... _ v
*,i
ii \ /
V
, — T
1
FIG. 304.
and then fasten the block to the angle-plate, at the required
angle with the table. We locate a plug in the hole first drilled
at C, as shown in Fig. 305, and then find with the height-gauge
the exact distance the centre of the hole is from the table. Then,
with a plug in the miller-spindle — which must run perfectly true
— we measure from the plug to the table, raise or lower the knee
until the centre of the spindle is the same distance from the
table that the centre of the plug in hole G is, setting it horizon-
tally, by measuring from the plug in the spindle to the angle-
plate, or the edge of the block to be drilled, with the height -
gauge. We have now everything ready to bore one of the angu-
lar holes ; which may be accomplished by using a draw-in collet
end-mill, or a single-pointed boring-tool, to finish the hole. The
other hole may then be finished in the same manner by reversing
the block on the angle -plate and proceeding as before.
278
TOOL-MAKING
In conclusion I may state that experience has proved that
more accurate and expeditious results can be obtained with the
height-gauge than the surface-gauge. Lay out your work with
the height-gauge ; prickpunch carefully where the lines intersect
Cfncfle Plata
Miller Platen
FIG. 305.
— using a glass where unusual "accuracy is essential — and indicate
carefully on the lathe face-plate ; drill the hole, and finish it by
boring. In this manner you will get as near perfect accuracy as
it is possible to get.
If you are machinist, tool-maker, or die-maker, learn of the
multiple uses of the micrometer -caliper and the height-gauge ;
and your ability to do fine and accurate work will be further de-
veloped and your earning capacity will be increased. If you are
a shop manager, superintendent, or foreman, furnish your de-
partments and tool-rooms with such tools and teach your men
how to use them ; as by so doing your shop will produce more
and better work accurately with ease.
CHAPTER XX.
Mould Construction.
MOULDS.
As not infrequently the making of moulds form part of the
tool-maker's work it will be well to devote a chapter in this book
to this interesting branch of his art.
Moulds are used to-day for the production of a variety of arti-
cles too numerous to mention. Rubber goods, soft metal ware,
.composition goods, glassware, china, and a thousand and one
other things that form an integral part of our twentieth century
civilization, are produced in moulds made by our most skilled
tool-makers. Let no one think that moulds require but little skill
to construct ; for if they do they will find themselves greatly mis-
taken. In order to construct moulds successfully the mechanic
must be skillful and accurate. In order that the articles pro-
duced in them shall be as desired, and exact duplicates of each
other, the moulds must be of the most accurate construction. In
fact an accurate mould must be constructed in much the same
manner as an accurate drilling-jig would be, as its products are
usually of the interchangeable class.
In order that the tool-maker may be assisted in deciding upon
the proper type of mould to adopt for the production of an arti-
cle of a given shape, size, aud form from a given material, I
shall illustrate and describe in the following pages a number of
sets of moulds of the most approved construction. The descrip-
tions will also point out the way to construct them properly.
MOULDS FOE PENCIL CRAYONS.
Fig. 306 shows a face view of a mould for pencil crayons.
As will be seen, it was made in two parts and produced twelve
crayons at once. Two castings A and B, 6 inches wide by 7
279
280
TOOL-MAKING AND
inches long, with lugs on one end of each for the hinge portions,
were planed all over, with care to get as smooth and true surface
as possible. The castings were very close-grained and totally
free from blow -holes. After they were planed they were scraped
L E
K u
f\f\f\f\f\f]f\f\f\ f\f\f\
a
f\f\f\f\f\f\f\f\f\f\f\f\
?
F
WWWWWWV_VWV_7WWW
'UUUUUUU
FIG. 306.
on the sides on which the moulds were to be, until they were as
near true as it was possible to get them. The lugs of the hinges
were then machined so that A fitted within B snugly. The
halves were then clamped together and the holes drilled and
reamed through the lugs for the pins D, which were driven in.
The plates A and B were then held In the vise and milled through
one side, leaving a rib on the side of each, as shown at C C, and
a depression R between them. While they were still clamped
together the centres for the twelve moulds were laid out and
prickpunched.
Next the pins D D were removed and the plates separated.
We now have a centre mark on the face of each plate for each
of the twelve moulds. The plate A was then strapped on the
table of the miller, dead square, and a line was struck from each
Fig. 307.— The Reamer.
centre across the plate. A convex cutter, of T 1 g--inch radius, was
then used, and, starting at the mark, was run along the line on
the face to within ^-inch of what was to be the total depth of the
mould. This was done on all of the twelve centres, and the
other plate was milled likewise, so that when the pins D D were
INTERCHANGEABLE MANUFACTURING. 281
inserted and the plates closed and clamped together there were
twelve holes, ^-inch in diameter, straight through the centre of
them, or a half of a ^-inch circle in each plate.
The plates were then stood with the side c c np, and a
drill -Jj of an inch under the final size, and extra long, was run
down through each of the ^-inch holes to within f -inch of the
bottom, the ^-inch hole in each keeping the drill perfectly cen-
tral. A special reamer, of the shape shown in Fig. 307, was then
made and fed down into the hole left by the drill, and by feeding
down very slowly a smooth round hole was made with the shape
of the point in the bottom. All the twelve holes were gone over
several times, until the exact depth was reached in each. The
mould was then opened, and all the dirt and chips were cleaned
out. It was then closed and reclamped. Several pieces of
T 3 ¥ -inch drill-rod which had been roughed all over were inserted
■ — one in each of several holes — and melted lead poured around
them. When they were cold the mould was opened and the lead
forms were withdrawn, thereby furnishing several good laps.
The laps were run at a high speed iu the drill-press, using a gen-
erous amount of oil and emery, and the holes, or moulds, were
lapped and polished to a nice, smooth finish. The plates were
then opened, and after being well cleaned with benzine there
were seen twelve perfect semicircular grooves of the size re-
quired in each plate, with dead-sharp edges that would leave no
fins on the work. The pins D D were then eased a little, so that
the mould could be opened without difficulty.
The next thing to be done was to make the latch F, shown in
Fig. 308. This was made of ^-inch flat steel and fastened to
J
OOOOOOOOOOQQ; :
'Wirt'ili 1
Fig. 308.
the plate A by a shoulder- screw. A small stud was let into jP,
for a handle H. The spring Q, of stiff spring steel, was made
and fastened so as to keep a strong tension on the latch F. The
lock-pin E was then made and hardened and inserted in the
282
TOOL-MAKING AND
plate B so that, in order to hold the two halves of the mould
fast and snug, the half B was brought down sharply on to A,
and the pin E striking the latch F it was forced back until it
snapped over the pin, thereby locking it. This j>roved a simple
and reliable latch and was quick to manipulate. The swinging
plate J for closing the channel B was then made of flat, cold-
rolled steel and worked out and finished to the shape shown,
with a small handle at K and swinging on the screw L. The
stop -pin M was let into A and filed off so that the plate would
swing over and rest on it, thereby closing the channel and pre-
venting the liquid material from running out. The other end
Balancing
Frame v^tA
FIG. 309.
Fig. 310.
Fig. 311.— Butt Mill.
was closed likewise, and the mould was then complete. It pro-
duced nice, smooth crayons without the trace of a fin or a lump
on the entire surface. A slight shrinkage which resulted in
them after they became hard, allowed of their easy removal from
the moulds.
MOULDS FOE LEAD BALLS.
In Figs. 312, 313, and 314 is shown a mould for casting a lead
ball on to a sheet-brass frame, as shown at Fig. 309. This device
was used as part of a balancing mechanism, and it was necessary
to have the balls all exactly the same weight and size, and in the
same position on the frame. The mould used is shown in three
views. Fig. 312 shows an inside view of each of the two sides ; Fig.
313 shows the bottom, and Fig. 314 the top. The two halves of the
mould were castings, and were machined all over to the same
size, with one dead-smooth side. After being scraped in order
to true them, one of them was held in the milling-vise, taking
care to have the vise true and the work down solid. Then the
butt-mill shown in Fig. 311 was held in the small chuck and the
table moved until the mill, while running, just touched the end
of the casting at C : the table was then moved outward and along
INTER CHANGE A BLE MANUFA CT VBING.
283
a certain number of thousandths of an inch (and a memorandum
made of it) for the first hole of the mould. Care had been taken
to finish the butt-mill to a perfect half-circle of the radius re-
I
J
M M
L O
Q
o o
o
o
o
o
o
o
o
o
b
9' '0
O
IqJ l
9©~ c
fO(
H
K
^o F
foV
,H.
K
)ov
"°w,
«««m
^ @ "
L
Fig. 312.
quired. The work was then fed against it and the mill let in the
required number of thousandths, or to the depth of exactly half
the diameter of the mill. The screw-dial graduation was then
Fig. 313.
noted, and the work brought back and moved along for the next
hole, and so on until the twenty -one halves were finished.
The other side I) was then held in the same manner, the mill
set and fed in the same number of thousandths as before and
rrn
G
rnp,
! C
c i rn
G — e — £±k — e-
-s — e — q — — e — e — e — e — e — e-K-s-~e — e — e — o-
m-
Fig. 314.
then each one milled to the same depth as the others. After this
was done the halves were removed, and two brass balls were
turned up and finished to exactly the same diameter as the
moulds, and one inserted in the last hole in each end of the plate
C. The other plate I) was then placed on the top, thereby locat-
ing the half-moulds perfectly true with each other. A hole was
then drilled at each end and reamed for the dowel-pins FF which
were made and driven into C. The holes in D were eased so
284 TOOL-MAKING AND
that D would go on the pins nicely. This proved a simple way
of locating the molds exactly true with each other. The holes
for the cap-screws G G were then drilled and the two sides G D
held fast together. A cutter just the thickness of the stock used
for the frames was then run straight through at L where the
two pieces C D lay together, to the depth shown. G and D were
then separated, and the centres laid out for the holes opposite
each mould, as shown at 1 1. The holes were then drilled about
£-inch deep, and reamed to allow the pins to be driven in to hold
the frames in place, as shown in the upper right-hand mould.
Each of the sides was then set up in the shaper and a tool just
the width of the frame at B centred with the holes i" I opposite
each.mould, and a channel planed into the centre of each mould,
as shown at J, to the same depth as L. The idea and form are
shown clearly in Fig. 312. The parts C and G were then put to-
gether and the screw G tightened and the holes drilled through
which the lead was to run into the moulds, as shown at H, using
a No. 40 drill and running into the centre of each mould, leav-
ing half a hole in each. The sides G and D — still together — were
then held in the miller-vise, and an angular cutter was used to
mill a trough for the metal at K to the length and width shown,
and, for depth, to within ¥ 3 ¥ -inch of the moulds, leaving the
small channels as shown. The two sides were then separated and
the faces polished with ' fine emery-cloth and all the burrs re-
moved, being careful to leave the edges of the moulds sharp.
The small pins were made and driven in to the holes 1 and then
filed down to just the thickness of the frames, and the tops
slightly rounded. A frame was then entered on to each of the
pins, as shown at M, thereby holding them all central, the chan-
nels J keeping them steady. The two sides were then put to-
gether, and the mould being complete, it was held in the vise.
The lead was heated to run freely, poured into the trough K and
running through the small holes H into the mould. After the
metal had set, the screws were loosened, D lifted off, the cast-
ing removed, and the balls chipped off at the small neck caused
by the holes H, leaving twenty- one balancing frames with a per-
fect half at the end of each, all exactly the same. The one thing
necessary in making a mould of this kind is a perfect mill and
INTERCHANGEABLE MANUFACTURING.
285
accurate spacing, and the work resulting will show no fin. The
machine used was a Cincinnati universal, and it was surprising
how dead accurate the spacing was, there not being a difference
in any of the work produced, either in size or shape.
MAKING MOULDS FOR TELEPHOKE-RECEIVER
PIECES.
The moulds here shown in Figs. 315, 316, and 317 are of a
type used in manufacturing imitation rubber or composition
goods for various purposes, such as syringes, bicycle handles and
Fig. 315.
Fig. 316.
Fig. 317.
Fig. 318.— The Piece
to be Made.
Fig. 319.
parts of the telephone. The moulds were used for moulding the
receiver case from a composition which, when hard, closely re-
sembles rubber, and is known as electrose. Moulds of this con-
struction are used in the hydraulic press, and the composition is
286
TOOL-MAKING AND
in a liquid form when pressed into the mould. The article pro-
duced is shown in a cross-section in Fig. 318. The top or face
is concave and the edges are rounded. The case is thin at the
centre and heavier at the outside, terminating in a square shoul-
der and a thread of 18-pitch. There is a -§ -inch hole through
the centre.
For the mould, pieces of flat soft steel were planed, clamped
with the smooth sides together, and a hole E at each end drilled
and reamed for dowel-pins. The pins were forced tightly into
the lower plate and projecting properly into the upper plate.
f^L
Fig. 320.
Fig. 321.
Fig. 322.
The sides and ends of the plates were then squared together in
the miller, and the twelve holes A were drilled through both sec-
tions and reamed to finish size. A pair of templets of the inside
and outside shape of the article were filed out and then special
counterbores, finishing -tools, and the tap were made. The first
tool, Fig. 319, was for the too of the case in the upper section,
and, Fig. 320, was for the face of the core F in the lower section.
N is the forming- and cutting-edge and the hole fits the stem of
the core. The straight face counterbore Q, Fig. 321, finishes the
twelve moulds in the lower plates, leaving them square at the
bottom and sizing them for the tap. This tap, Fig. 322, as well
as the three counterbores, had a central or guide-pin fitting for
the reamed holes.
The upper plate was clamped (not too tightly) to the drill-
press table, with one of the holes A directly under the stem en-
tered the hole T, as shown in the cross-section of the plate. The
INTERCHANGEABLE MANUFACTURING. 287
counterbore was then fed clown iuto the plate to the proper depth,
and all the twelve holes were finished in this manner, which com-
pleted the upper plate, except the lapping.
The first counterboring of the lower plate was accomplished
in the same manner by the fiat-faced counterbore, Fig. 321. The
next operation was to tap the holes, which was done in the same
drill-press, running very slowly and using plenty of soap-water
as a help iu cutting, and by careful work, and by running the
tap in and out a few times, a sharp, smooth thread was secured.
The numerous flirtings of the tap, Fig. 322, worked admirably.
There was also very little lead to the tap, as we wished the first
thread in the finished case to be as full as possible.
The cores were then made of machine steel, first cut into
lengths for two. These pieces were first turned at both ends to
form the stems D to be driven tightly into the hole A. The pieces
were then cut in two and held by the stem in a nose -chuck that
ran perfectly true, when the stud at the opposite end was fin-
ished to fit nicely in the holes A in the upper plate. After this
was done to all of them, the facing- or forming-mill, Fig. 320, was
used for the face of the cores. The cores being held by the stem
D in the nose-chuck, the centre in the end of the shank of the
facing-mill was placed on the tail-centre and the short stem,
turned on the face of the core, entered the hole in the facing-
mill, which was then fed in until the shape and size desired was
produced on the face of the core. The twelve cores were then
highly polished and driven tightly into the hole A in the lower
plate. All burrs thrown upon the face of the plate by the tools
used were then removed, leaving a sharp edge to each of the
moulds. '
There then remained to finish the moulds the lapping and
polishing of the upper plate which formed the faces or tops, and
which required a high shining polish as they left the mould.
We made a few lead laps by pouring lead into the sections B,
casting them around steel stems, which in use projected into the
holes A, and then, by using flour, emery, and oil and running the
laps as fast as possible, the moulds were lapped to a finish and
polish that was very nearly perfect. By putting the two plates
together it was seen that there was not the slightest defect in the
288 TOOL-MAKING AND
alignment of the holes A in both, testing them as we did with a
standard plug-gauge. One side of each of the plates was then
marked "Front" to avoid mistakes.
When moulding the cases, the upper plate was removed, and
the composition was poured over the face of the lower plate.
The upper plate was then replaced, and the projecting stems of
the cores F in the lower plate entered the holes A in the upper
plate, thereby preventing the liquid from squeezing out and also
forming the hole J in the finished case. The two plates were
then placed under the hydraulic press and sufficient pressure was
brought down on them to press the fluid into every portion of
the moulds, the pressure being so great as to force every bit of
surplus composition from between the sections. This composi-
tion was used while very hot, and required a few seconds to cool
before removing. When cooled, the upper section was removed,
and the slight shrinkage resulting from the cooling allowed the
finished cases to be removed by screwing them out of the lower
plate by hand. When thus removed they had a fine, smooth
polish on all the outer surfaces and a good, sharp, smooth thread.
HOW AN ACCUEATE SET OF MOULDS WAS
MACHINED IN THE PLANEB.
In Fig. 323 are two views of the finished lower section of a
mould used for moulding square sticks of crayons with one end
curved and tapered, as shown in Fig. 324. There were ten sets
of these moulds to be made, and as we were getting a good price
for them we were glad to get the job. Now, as will at once be
seen, the job is a milling job, and the universal milling-machine
the machine to do it in. As we had no milling -machine, how-
ever (universal or otherwise), we had to look around for other
means.
At last we decided that they could be finished throughout in
the planer by the use of a few special tools and attachments.
Fig. 325 shows how the sections of the moulds are cored out at
the back at A A, leaving a rim all round the outside. These
sections, or plates, were of cast-iron of very close grain. The
twenty castings for the ten moulds were first planed on the top
INTERCHANGEABLE MANUFA CTURING.
289
and bottom, and the mould face of each scraped, so that the sec-
tions would surface at all points. The sections were then paired
and the holes B B drilled and reamed through them, in the
positions shown, for the three dowel-pins - of Stub steel. These
THE JOB AS FINISHED IN THE PLANER.
c c
c
c
c
c
B
c
c
c
c
c c
!;';,
r
,,\
" 'S
■wm
CROSS SECTIONAL FRONT VIEW.
Fig. 323.
pins were driven tightly into one section of each of the ten
moulds, and the holes in the other sections eased up. The two
sections of each mould were then numbered and the moulds, with
Fig. 324.— The Piece Produced in the Moulds.
the sections clamped together, were then strapped on the planer-
bed and their four sides planed square with each other and with
the mould faces of the section, care being taken to finish the lot
Fig. 325.
of ten to the same width and length. We were now ready to
finish the moulds proper, and to do this the tools and fixtures
shown in the accompanying illustrations were made.
As seen in Fig. 324, the crayons produced in the mould were
required to be T ^-inch square, with one end tapered and curved
19
290
TOOL-MAKING AND
to a 1^-inch radius. They were to be finished so that they would
present a smooth surface on all sides, without fins and with the
ends tapering symmetrically. To accomplish this result in the
planer it was necessary to provide means for raising the form-
FIG. 326.
ing-tool (for finishing the moulds) so as to produce the shape
desired. The first thing made was a templet. This templet was
worked out with one square side to work from and then finished
to a 1^-inch radius. It was used to finish the cam shown in two
views in Fig. 326 and on the
planer-bed in Fig. 327. This
cam was of cast-iron with ears
at each end to admit fastening-
bolts, and with the cam faces
long enough to take in the entire
length of mould sections. It was
first planed on the back and the
CAM FOR RAISINQ TOOL-HOLDER.
FORMING TOOL.
METHOD OF FINISHING THE MOULDS AND DUPLICATING THE CURVER TAPER ENDS.
FIG. 327.
tongue G fitted to the central slot in the planer-bed. The cam
face F F was then planed up and finished to the templet, shown
at left of Fig. 326, after making sure that it was at right angles
with the sides of the tongue G. The front side of the casting was
also squared so as to have a locating side for the mould sections to
INTERCHANGEABLE MANUFACTURING.
291
square against. Next came the tool -holder. This was got out of
a bar of 1^-inch square mild steel, bending and drawing down one
end to If by ■$, to the shape shown in the front and side views
of Figs. 327-330. The end of the extension at N A was milled
through with a § -inch cutter to admit the roller of machine
steel, which was finished to fit the slot N N snugly, and to If inch
in diameter, located by the T yinch stud P to revolve freely within
the holder. A f -inch square hole was worked through the holder
to admit the forming-tool, Fig. 331, care being taken to get it
square with the sides of the roller 0. A hole was also drilled and
tapped to admit the set-screw Q for holding the forming-tool.
This tool, Fig. 331, was of f -inch square tool steel, finished at R
to a y 5 ¥ -inch right angle, terminating in a square surface on each
side at S. The correct shape of the cutting portion was carried
back to the full thickness of the tool, giving the cutting-edge the
amount of clearance shown. This completed the tools necessary
to finish the moulds in themselves.
Now, as will be seen in Fig. 323, the moulds are constructed
to produce twelve crayons, and it is necessary to space the twelve
moulds C accurately, so that those in both sections will coincide
INDEX NOTCH.
Fig. 328.
with each other perfectly when the sections are fastened together.
To do this, some kind of an indexing device was necessary. The
use of the notched hand-wheel, Fig. 328, and the "flopper" or
index-pawl, Fig. 329, answered for this, and allowed of the spac-
ing of the moulds being acccomplished with rapidity and very lit-
tle trouble. This hand- wheel was fitted to key on to the horizon-
tal feed-screw of the planer and had a notch cut into its rim in
the position shown. The "flopper" or index-pawl consists of
292
TOOL-MAKING AND
s3
Fig. 330.
FORMING TOOL.
three parts: the back-plate I, the flopper or pawl J, finished at
K to fit the notch in the hand-wheel, and the shoulder-screw L,
for fastening the parts together. This completed all fixtures
necessary to the finishing of the moulds.
The manner of finishing the sections in exact duplication of
each other and spacing them correctly is shown in Fig. 327.
This is sufficiently clear to be understood with a
short description. The cam for raising the tool-
holder is fastened to the planer by bolts at either
end. The section of the mould marked "the work"
is located squarely against the square front of the
cam; lengthwise and sidewise against the stop.
It is then clamped securely to the platen of the bed.
The tool-holder is now fastened in the tool-post — the
apron of which has first been set perfectly square
with the planer-bed. The forming-tool is fastened
within the holder — squaring it with the work by
means of the parallel edges S S and allowing it to
project out of the holder so the point of the cutting-
edge is T \-inch below the face of the roller, as in
Fig. 327. The stroke of the planer-bed is then set,
the hand-wheel fastened on the feed-screw, and the
"flopper" clamped so that the end K will enter the
notch in the hand-wheel, the back-plate of the "flopper" being
clamped to the upright side of the planer.
Everything is now ready: Starting from one side of the
mould-plate, the forming-tool is moved over by revolving the
hand-wheel a given number of times, and the indexing-pawl is
dropped into the notch. The planer is then started and the form-
ing-tool is gradually raised, thereby finishing and cutting the
mould at this end in exact duplication of the shape of the cam
face. To gauge the depth of the moulds the tool is fed down un-
til the straight edge S S of the tool touches the face of the mould-
plates. When the first mould is finished the tool is moved over
the necessary distance by revolving the hand-wheel and indexing
in the notch, and the operations are repeated until all twelve of
the moulds in the section-plate are finished. The plate is then
removed and another set up in the same manner and finished.
y
R R
FIG. 331.
[NTERCHANGEABLE MANUFA CT URING.
293
The twenty sections or mould -plates are all finished in this man-
ner, each one being an exact duplicate of the other, and all coin-
ciding perfectly when put together.
The method used here for finishing these moulds can be
adapted for a large variety of different work, as will be at once
seen, and the labor and expense incurred will not exceed that
called into play if the work was done in the milling-machine.
MOULDS FOE BICYCLE HANDLE-TIPS.
In Figs. 332 and 333 are shown plan views of the top and
bottom, respectively, of a set of moulds for the moulding of com-
position bicycle handle-tips, and in Fig. 336 a cross-section of
the mould complete. The piece produced is shown in Fig. 335
and the drawn and perforated tin shell which forms the skele-
ton of the work, and around which the composition material is
Fig. 332.
moulded, is shown in Fig. 334. The perforations in the shell or
ferrule are to allow of the composition running into them when
the tips are being moulded. The moulds shown produce four-
teen tips at a time, and as the construction of them entails con-
siderable practical knowledge and skill, it is of sufficient interest
to describe.
Two mild-steel plates for the two sections A and B of the
moulds which form the top and bottom respectively, were first
planed all over, and one side of each scraped until they surfaced
294
TOOL-MAKING AND
■ — when placed together — at all points. Both plates were then
clamped together and holes drilled and reamed through both for
the three taper dowel-pins C C C. The pins were then got out
Fig. 333.
and driven into the bottom plate, and the two sections placed to-
gether, and a cut taken off all four sides to get both plates dupli-
cates of each other. The top section was then removed from the
other and the face laid out for the fourteen cores C in the rela-
tive positions shown in the plan views, Holes were then drilled
N through the plate at these points and reamed to size ( T 7 g-inch),
./£
w
. G
Tc
M=='E K E v E r E V KE.„
\> '. : -J
FiCx. 331.
Fig. 335.
Fig. 336.
and then countersunk slightly at the back. The two sections
were then reclamped together, the three dowels C C C locating
them — and the holes in the top section transferred to the lower,
drilling into a depth slightly less than the total depth to which
the moulds were to be finished, as shown at E in the cross-sec-
tional views, Fig. 336. The upper section was now removed and
the holes drilled in the lower section counterbored to ^-inch in
depth, arid in diameter to the size of the reamer, Fig. 337. The
semicircular channels in the face of each mould at F were then
INTERCHANGEABLE MANUFA CT UBING.
295
let in, and finished by using the tool shown in Fig. 338, the end
of which, at H, fitted the holes reamed by the reamer, Fig. 337,
snugly, the cutter J finishing the channels to the required
depth. A finishing, reamer of the exact taper and size required
was then let in, finishing the moulds to the shape and depth
shown in Fig. 336, the upper edges or largest diameter of each
just meeting the inner edges of the semicircular channel F, leav-
ing a sharp edge all around. The moulds were then lapped to
a high finish, getting all marks and scratches out by the use of
Fig. 338.
Fig. 339.
the copper expansion lap shown in Fig. 339, and flour, emery,
and oil. The lower section of the moulds was now complete.
To finish the upper section there remained the fourteen cores, as
shown in the plan view, Fig. 332, and in the cross-sectional views,
Fig. 336, at G. These cores were made in the lathe, and were of
machine steel, first cutting off pieces of sufficient length to get
out two cores, and then centring them and turning down each
end to fit tightly the reamed holes in the upper-section plate.
The pieces were then cut in two and held in a nose -chuck by the
finished stems, and the core faces turned and finished to the re-
quired shape and size with a forming-tool — that is, to just fit the
inside of the tin ferrules, Fig. 335. The stems of these cores
were then driven into the holes in the upper sections, shoulder-
ing tightly within the plate as shown at D. The mould was now
complete and ready for work.
One of the perforated tin ferrules, Fig. 335, was slipped on
to each of the cores and the composition to be moulded spread
into the moulds E. The two sections were then located together
by the three dowels C C C, and the mould placed under the
296 TOOL-MAKING AND
hydraulic press and the two sections forced together, which
caused the composition to compress to the limit, with the surplus
forced out from each mould and into the semicircular channels
in the face of the sharp edges on the insides, trimming the stuff
from that within the moulds. The mould was now removed from
the press and the sections separated, when, by rapping the lower
section and the back with a mallet, the moulded pieces dropped
but, the result being fourteen highly finished tips of the shape
shown in Fig. 344. The perforated tin ferrules on the inside of
the tips made them stroug and durable, and the presence of the
pierced holes L around the shells for the composition to run
into, eliminated the possibility of the two parts separating, or
the composition loosening or chipping off.
MOULDS FOR " POKER-CHIPS. "
In Fig. 340 is shown a cross-section view of a mould for
poker-chips, and in Fig. 341 a plan view of the bottom section.
As both sections of this mould are exact duplicates of each
other, the one illustration will serve for both. The manner of
o O
R "Q "'"r Q "R "ST R"' Q "r: ;
t,.;... '■..- ^ i_L
FiG. 340.
preparing the mild-steel plates for the sections M and N, Fig.
340, and the manner of locating them by the three dowel-pins
OOO are the same as that pursued in the other. As can be seen
in the plan view of the section-plate, Fig. 341, the mould had a
capacity of sixteen chips. The manner of spacing these moulds
and finishing to coincide with each other is as follows : The two
plates after being doweled together are planed square on all
sides; one side of each then marked to work from, choosing op-
posite sides. One of the sections is then clamped facing the
spindle to an angle-plate on the universal milling-machine, with
the marked end resting squarely on the miller-table. The form-
ing-mill, Fig. 342, is then held in the miller-chuck, and the table
INTERCHANGEABLE MANUFACTURING
297
raised until the work is in line with the first row of moulds.
The table is then moved along until the cutter will just touch the
FIG. 341.
side of the plate. We now move the table longitudinally the
exact distance required — by noting the graduated dial on the
feed-screw — and the first mould is finished by moving
the work against the cutter ; letting it in the number
of thousands required. The work is then backed out
and the table moved for the next mould, treating
each mould of the first line in the same manner and
getting them exactly the same number of thousands
apart. When the first row is finished, the table is
raised the same distance as the space between the
first row of holes, then, by starting from the same side
for the first row, the second row of holes is finished,
and so on until all are complete. The one thing nec-
essary is the accurate spacing and sinking of the
moulds, being sure to take up all back lash in the feed-
screws before starting the divisions. When letting in the forming-
cutter, a generous supply of oil was kept running on the cutter,
Fig. 342.
298
TOOL-MAKING AND
the cutting-edges of which had been ground and oil-stoned to
take smooth polishing cuts.
The finishing of the other sections was accomplished in the
same manner as the first, starting from the marked side and
working from it as in the other. In the plan view, Fig. 341, Q Q
are the moulds and B B the semicircular channels for the surplus
stock to run into. These moulds were required to be finished so
that the outer edges of the " chips " produced would be about
0.005 higher than the centres, this being necessary in order for
the chips to "stack "well and even. The moulds were lapped
and polished smooth by means of a lead-lap in the drill-press,
running it at a high speed in order to get a high finish in the
moulds.
SPHERICAL MOULDS.
Moulds and dies for spherical forms of various radii, such as
globes and rings, often have to be formed in the lathe. Such
moulds are used particularly in rubber factories for balls and
FIG. 343.
bicycle tires, and the little tool illustrated in Figs. 343 and 344
was designed for such requirements, as it was found rather ex-
pensive to make forming-tools for each size of mould that had to
be made. The fixture was designed to be bolted on to the car-
riage of the lathe by bolts in the T-slot of the tool-carrying block,
INTERCHANGEABLE MANUFACTURING.
299
thus giving it all the ordinary movements given to a lathe-tool,
with the additional circular ones.
The tool, as shown in the drawing, consists of the cast-iron
base, having a tongue which fits the T-slot of the tool-block, and
is firmly held thereon by the bolts shown. A cap is fastened to
the base by counterbored screws, while projections upon it and
a groove in the base serve to locate the cap. The worm-gear,
Pig. 344.
having trunnions integral with it, is journaled in the extension
or wings of the base and cap. Meshing with the worm-gear is
the worm, the shaft of which is journaled by the base and cap
and extends toward the front of the lathe, where it terminates in
the hand-wheel at a convenient length. An oblong slot is cut
in the worm-gear to receive the turning-tool, which is fastened
by the central set -screw.
As moulds and dies are usually made in halves, it is not often
required to turn out more than this, but proper proportioning of
the fixture allows as much, as two-thirds of the sphere to be
turned out. The device, of course, will turn out moulds for cir-
cular rings as well as for balls by simply setting it out from the
line of centres to the required radius.
CHAPTER XXL
Special Tools, Fixtures, Devices, Arrangements, Con-
trivances, and Novel Methods for Metal-Working.
THE DEVISING AND CONSTRUCTING OF SPECIAL
TOOLS.
While the constructing of the regular types and standard
classes of tools necessitates skill, accuracy, judgment, and experi-
ence on the part of the tool-maker, it is in the devising of special
means for the rapid and economical production of special work
that his ingenuity is utilized. The ability to devise special tools
for special work is one to be prized, and should always be en-
couraged and developed. In this chapter are illustrations and
descriptions of a large variety of special tools, fixtures, devices,
arrangements, and novel methods for metal-working ; by making
himself familiar with them the mechanic will find no difficulty in
devising means for the rapid production of any special part;
while the descriptions of the proper ways to make them will
show how to avoid all unnecessary expense and labor.
A SET OF TOOLS FOE MACHINING A CAM.
The illustrations show a set of tools for machining a repeti-
tion casting of unusual shape, which was used as a cam on an
automatic machine for making fruit-baskets, and, as some of the
tools are of a novel and improved design, a slight description of
them will suggest their use for other work.
The casting machined is shown in Fig. 315. It is, to say the
least, a rather difficult piece to machine, because of the irregular
cam surface. This cam surface was required to be finished very
accurately and so that the castings, when finished, would inter-
change perfectly. The other portions of the casting to be ma-
chined so as to interchange were the boring and reaming of the
300
INTERCHANGEABLE MANTJFA CTUEING.
301
hole A, the facing of the hub at G, of the sides C, and the finish-
ing of the conical surface at B. The hub B was left rough.
The number of operations required to finish the casting was
three — the first being done in the turret-lathe and the other two
Fig. 315.
in the engine-lathe. The first operation consisted of boring the
hole A and reaming it, facing the hub G, and machining and fin-
ishing the conical surface B. The tools used in this operation
Fig. 346.
are shown in Figs. 346 to 350. Fig. 346 is a combination boring
and hub-facing tool used to bore the hole A and face the hub G
at the same time. It consists of a long stem H, with the cutter
Fig. 347.
Jin a slot in the end held by the taper-pin J, and the hub-facing
tool-holder K, which is located on the bar by the set-screw L,
the point of which screws into a milled channel in the cutter-
bar, as shown at Q. The hub-facing cutter iVis held in position
302
TOOL-MAKING AND
by the two set-screws -ZV N. P is the usual split bushing as used
in the turret-lathe.
For reaming the hole A the reamer Fig. 357 is used. This
reamer consists of the body Q, of tool steel, and six cutters or
blades T. These blades are let into inclined channels, as shown
by the dotted lines at U U, to allow the readjustment after being
worn, or after grinding. The blades are held by taper-headed
screws W which are let into the centres of the narrow-sawed slots
V. By tightening these screws the metal is forced tightly against
the blades, thus holding them securely.
Fig. 348 shows the tool used for roughing off the conical sur-
face S. The tool has three cutting -points K and is gradually
Fig. 348.
slid along under the surface by the hand-lever, the shank of the
tool being held in the tool-post. This surface was finished by a
flat-bladed tool of sufficient width to take the entire line at once.
The second operation, facing the two sides C C, thus sizing
the width of the cam face, is done in the lathe by the special
double-facing tool, Fig. 349. Three castings are located on an
INTERCHANGEABLE MANUFACTURING. 303
arbor at once and fastened by a nut. The tool is held in the
tool-post in the usual way.
The last operation, machining the cam surface, was the most
difficult. It also was done in the lathe with four special fixtures.
These were: A special slide-rest for the cutting-tool, a special
Fig. 349.
cross-slide for the lathe, a combined master-cam and chuck, and
a locating- and supporting-stud for the work. These fixtures, in
position on the lathe with the work, are shown in Figs. 350 and
Fig. 350.
351. The master-cam and chuck was a forging, which was first
fitted to the spindle of the lathe, after which the chuck portion
was finished with an internal conical surface at 1 1 as a locating-
point for the conical surface D D of the work. The cam portion
was then laid out and finished on the universal milling-machine.
304
TOOL-MAKING AND
The stud or arbor for the work was of tool steel finished as
shown, hardened and screwed tightly into the chuck portion of
the master-cam, shouldering on it at II H as shown ; the surface
M was then ground to fit the work.
The special cross-slide for the lathe is in reality a compound
rest, the only difference being that the smaller rest does not swivel.
The cam-roller was of tool steel and was hardened and ground
to a smooth finish and located on a hardened and ground jfin G
Pig. 351.
within the bracket K. A chain It is attached to the hook at the
back of the slide and is supported by a roller at the back of the
lathe, with a heavy weight fastened to the hanging end of it.
Thus the movement of the cross-slide is derived from the master-
cam S S working against the cam-roller. As can be seen, the
construction of the cross-slide is strong and the rigidity of the
cutting-tool is insured. The cam surface was first turned to
within a few thousandths of an inch of the finish size and then
finished to gauge by grinding — this being easily accomplished by
the use of a small tool -post grinder driven by a round belt from
a drum overhead.
CUTTING A COARSE-PITCH SCREW.
Fig. 352 is a sketch of a coarse-pitch screw which, because of
the unusual pitch, was cut and finished under difficulties. The
screw was 30 inches long, 2 inches in diameter, with one thread
to 3 inches. After rigging up the gears on the strongest lathe in
the place it was fouud that the slowest speed we could get was
too fast, and after breaking all the teeth a new pair of gears was
INTERCHANGEABLE MANUFACTURING. 305
got out to replace the broken ones. A piece of machine steel
was turned up and reduced at one end to screw into the tapped
hole for the gear-screw iu the end of the lead-screw of the lathe,
and an 8-inch pulley keyed on this extension piece. A spare
countershaft was now located and fastened to the floor. The
driving-belt was removed from the lathe and we then belted
Fig. 352.
from the main shaft to the countershaft on the floor and from
the couutershaft to the pulley of the lead-screw. We thus re-
versed matters, and instead of the lathe-spindle driving the lead-
screw, we had the lead-screw drive the spindle. Thus while the
lead-screw fed the thread-tool at the proper speed the work
turned very slowly and the screw shown and several others, as
well, were finished without any further trouble.
MAKING THIN THREADED BRASS EINGS.
In Figs. 353 and 354 respectively are shown the means used
for accomplishing a nasty little job in a very simple manner.
We were making a lot of thirty -two acetylene-gas lamps, and
during the process of manufacture it was necessary to make and
sweat a threaded brass ring into one of the shells. These brass
rings were made from 2-inch brass tubing and were required to
be finished to ^-inch wide and threaded 22 -pitch. The tubing
had a wall of only Jg-inch, and as it was impossible to cut off
and thread the rings in the usual manner in the lathe, the fol-
lowing simple means were used: A piece of soft wood was
turned up on centres to fit a length of tubing, as shown in Fig.
353 — finishing one end somewhat smaller than the other, so that
the tubing could be forced on. Then by driving this wooden
arbor between the centres, the rings were cut off with ease, as
shown, without in the least affecting their trueness. After being
cut apart the rings would come off the arbor easily. The burrs
were then removed with a hand-tool, and the rings were threaded
by holding and locating them in a wood -chuck of the shape
20
306
TOOL-MAKING AND
shown in Fig. 354. This chuck was of soft wood and was
turned at G so as to allow of its being held in the regular lathe-
7 yr— t— ,-
FIG. 353.
chuck ; then bored ont on the face, so that a brass ring would fit
tightly within it and true itself against the shoulder at H H.
Four round-head screws at J J J,
when tightened down against the
edge of the ring, also helped to hold
it. The rings were threaded in
this manner by the usual threading -
tool and fitted to a plug, and were
removed from the chuck by screw-
ing the plug in for a few threads
and pulliug the ring out. Some of
the rings would not fit the chuck
tightly, but by taking a piece of
wet waste and wetting the locating
portion of the chuck, it would
shrink sufficiently to hold. Any
one who has ever tried work of
this kind with the usual means at hand in the lathe, will appre-
ciate this simple and effective method.
FIG. 354.
A DEILL-PEESS JOB.
The sketch, Fig. 355, shows how an unusual job was accom-
plished in a simple manner with the best means available, which
were— to say the least — not meant for the job. The work was a
base casting of a two-cylinder pump model, and it was necessary
to bore two lf-inch holes in it in the position shown. The lathe
we had was too small to allow of swinging it on the face-plate,
and the only drill-press in the shop (which was a private experi-
mental shop) was an 8 -inch sensitive drill. So by means of the
INTERCHANGEABLE MANUFACTURING. 307
adjustable cutting-tool shown we did the job on the small drill.
First we drilled and reamed two small holes the required distance
apart for the centres, as shown at K, as locating- and truing-points
for the tit M of the tool R as shown. The tool was fastened in
Fig. 355.
the chuck and the work located and clamped to the table and
the holes finished as shown in the sketch. The tool used for
this job can be used for a variety of others as well.
A "STEP- JIG."
The sketch, Fig. 356, is meant to show one end of a hard rub-
ber plate which was accurately finished on the side to 7| inches
wide, 5^ feet long and to f -inch thick. In this rubber plate there
Fig. 356.
were to be drilled fifty-two rows of holes, ^-inch apart and 625
holes in each row, the size of a No. 60 drill. The number of
holes in all was 32, 500, and each and every one of these holes
308
TOOL-MAKING AND
description is required.
Qc
*eQ
i° °j
were required to be accurately spaced, as the rubber plate was
to be used as a part of the mechauism of a music-box, a steel pin
being afterward inserted into each hole. There was to be a
^-inch margin on all four sides of the plate.
The jig used for drilling and spacing the holes is shown in
two views in Fig. 357. As the sketch explains itself, very little
As shown, there is one row of fifty -two
holes running in a straight line
from J to J, and ^-inch from the
holes at the extreme ends of this
line other holes as shown at 1 1.
These two holes are for spacing the
rows of holes in the plate when
drilling, by drilling the first hole
^-inch from the end of the plate
and then locating the jig for the
next row by inserting the two locat-
ing-pins K K into and through the
holes 1 1 and into those coinciding
in the plate. The holes in the jig
were spaced and located in the
universal milling-machine by using
a small stiff centre -drill for cen-
tring all holes, and afterward drill-
ing and reaming them on the sensi-
tive drill. The manner in which the jig is used and the work
drilled can be understood from the sketches. The drilling of
these 32,500 holes took some time, and after each day's work
on them it was necessary to lay the rubber plate on the planer-
bed and put heavy weights on it so as to prevent it from warping
during the night.
io pj
Fig. 357.
A DEILLHSTG JOB IN THE PLAKEK.
I saw the following combination used to advantage one day
while looking through a small country jobbing-shop. It consisted
of a 1-inch drill, a lathe-centre, a dog, and a stick of wood about
three feet long. They were used for drilling three 1-inch holes
in the bed of an old planer. The lathe -centre was clamped in
INTERCHANGEABLE MANUFA CTUR1NG.
309
the tool-post of the planer and the dog fastened to the shank of
the 1-inch drill. The point of the drill was entered into a cen-
tre-punch mark in the planer-bed, and the point of the centre en-
FiG. 358.
tered into the shank end of the drill. With
one hand the drill was turned by using the
stick of wood as a lever, and with the
other the tool-head was fed down. In this
manner the holes were drilled. While the use of the lathe-centre
and the cross-head as an ''old man" was all right, I thought
that the dog and stick method was rather obsolete, until the
"boss" of the place told me that they had no ratchet.
A SPRING- WINDING FIXTURE.
Fig 358 shows two views of a simple and handy little spring-
winding fixture which, as the sketches show its construction
clearly, requires little description. The body T is a piece of
finished ^--inch square mild steel, and one end is constructed and
fitted for winding gauged springs, while the other end is for
closed springs. The end for the gauged springs has a hole
through it at Z for the rod L on which the spring M is wound.
For a gauge for winding the springs, the spring U is used, it
being located and fastened to the sides of T by the small clamp
Y. V is a small plate fastened to the body at X, with a guide-
way at W for the wire. When in use the rod L on which the
spring is to be wound and the end of wire are fastened in the
lathe-chuck, the projecting end of the rod entering the hole Z in
the winder. Then the winder is given a couple of turns around
the rod, so that the gauger U will have twisted around the wire.
310 TOOL-MAKING AND
The fixture is then fastened in the lathe tool-post and the lathe
started, holding the wire tight by the hand and letting it run
down the guideway as shown.
The other end of the winder is used as shown. The screws
P P and are for adjusting a guideway for the wire which
passes under the roller Q and is wound around the rod S, as
shown at R.
A SOLDEEING FACE-PLATE.
One of the handiest things around the jobbing-shop is a solder-
ing face-plate. The number of small, odd, and intricate little
jobs which can be accomplished with ease by its use is surpris-
ing. The one we had was fitted up to locate and fasten on the
face-plate of the Hendey-Norton lathe. It consisted of a disk
of cast composition about one inch thick and slightly under the
diameter of the face-plate. After being faced on one side it
was located and fastened to the face-plate by means of four
countersunk head-screws which were let in from the back, thus
allowing of its easy removal when through with it. One of these
plates should be kept in every tool-room, and one, 1 inch thick,
will last a long time and pay for itself over and over again be-
fore being worn out.
MAKING COLLET SPKUSTG CHUCKS.
The following kink I found very handy when making collet
spring chucks of the shape shown in Fig. 359. After finishing
them in the lathe, leaving, of course, enough stock to lap and
grind to a finish, face them on an arbor and saw the spring slots
as shown — that is, at the end of each
slot, as shown at T and V, instead
of cutting completely through at this
point, leave a very thin wall of about
^-inch long at the end of all the cuts.
Then harden and temper the chuck
FIG. 359.
as desired, and after lapping the in-
side to size, place on another arbor and grind the tapers as re-
quired. Then take a small, narrow broach and by entering it
into the slots and hitting it a sharp blow with a hammer the thin
INTERCHANGEABLE MANUFACTURING. 311
wall will break through. This kink I have used to the best ad-
vantage iu shops which had no grinding facilities. When pro-
ceeding as aforesaid, it was possible to finish the outside and
tapers to size before hardening without the possibility of the
chucks running out to a noticeable extent. Of course in work
of the utmost accuracy this method would not do. But then
again, work of the utmost accuracy is not accomplished in shops
where the tool facilities are not up to date.
A FLAKING-STICK.
In Fig. 360 is shown a sketch of a little kink which, while no
doubt old to many, may be new to some. It is a flaking-stick,
and may be used to produce that circular flaking often seen on
the inside of watch-cases and often desired for a finish on differ -
-Lead pencil
Emery doth
Fig. 360.
ent polished small parts. It consists of a stump of a lead-pencil
and a piece of emery-cloth, as shown, fastening both in the chuck
of the small drill -press, then running it fast and coming down
on the work for a second and then shifting it and coming down
again. The finished effect is fine when a little care is taken to
move the work evenly.
DRILLING HOLES IN A HELICAL SURFACE.
Fig. 361 shows a drilling fixture, with the work in position,
for drilling a 500 lot of malleable iron castings of the shape
shown. In these castings it was necessary to drill twelve
equally spaced holes c c c around the helical portion. The de-
sign of the fixture and the manner in which it was used are
shown clearly and can be understood without description.
MILLING IN THE DRILL-PRESS.
Fig. 362 shows the use of a small fixture' for milling in the
drill-press, a portion J out of a small eccentric cam-shaft P.
312
TOOL-MAKING AND
F is the fixture in which the work is located in the hole G. The
work is located and prevented from turning while being ma-
^^
f~ ~J
Nut tor Supporting
Work
I
-Locating Pia
Collar wilh Hardened
Bushlugs
FIG. 361.
chined by a portion of P resting in a turned depression in the
top of the fixture at H. A hardened taper-pin R, with a flat
face to bear against the work, secures it, as shown. L is the
shank of the cutter-holder which is fitted to the drill-press spin-
■Wf^
Fig. 363.
die. The cutter K is keyed on and further secured by the nut
and washer. The stem M of the cutter-holder runs in the hard-
ened bushing N while the work is being machined.
A SIMPLE LATHE-CHUCK.
In Fig. 363 are two views of a simple chuck used for locating
and holding a cast-brass ring, while the inside at D D was being
INTERCHANGEABLE MANUFACTURING.
313
bored and the edge E E rounded by the tool at the right.
There were a hundred of these rings to be done and the portions
designated were the ouly points finished. The chuck proper
was of cast-iron fitted at A to the lathe-spindle, and the face bored
out for the work, as shown. The three set-screws B at the back
were for locating the work true sidewise, while the three around
the outside at Cwere for centre -truing and holding it. To fasten
or release the work it was only necessary to tighten or loosen one
of the screws C.
TEIMMING SHEET-BBASS BLANKS.
The arrangement shown in Fig. 364 was used for rounding
the edges of sheet-brass blanks y^-inch thick and If inches in
diameter. There were 2,000 of these blanks and they were
punched in a plain blanking-die. Finishing the blanks by the
means available in a jobbing-shop was impossible, and for a
Truing BtrfEe:
Sc^
1 2M)
a
Fig. 364.
while we thought that we were "up against it"; but one of the
men. who had done considerable mould making in his time, told of
a method which he had seen used with great success for finishing
the edges of "poker-chips." This method was adopted, with the
result that the job was accomplished with ease and at a very low
cost. The piece A is fitted to a hole in turret of a small screw-
machine, with a piece of hard spring rubber B attached to the
projecting end of the press R. A duplicate of this piece R is
held in the chuck on the spindle of the screw-machine. The
rounding-tool is fastened in the front tool-post, while the turn-
ing-buffer is located in the back one. To machine a blank it is
held by the fingers against C, while the piece R with the rubber
314
TOOL-MAKING AND
front B is brought against it by moving the turret up and forc-
ing the rubber against the blank, which is trued and sufficient
pressure applied to hold it. The rounding off is then accom-
plished by the tool, and the blank, is released. The blanks were
all finished to size in this manner without any trouble.
A DIE-MAKING KINK.
Fig. 365 shows a little kink which to the best of my knowl-
edge is original. It consists of simply taking the upper half of
a brass door-key and soldering it to the centre of a templet for a
handle. When the templet is large, as is the one shown, the sol-
FiG. 365.
FIG. 366.
dering of the key to it iustead of a piece of wire is a great con-
venience. When the die is finished the key can be removed and
laid away in one's drawer until required again.
A SIMPLE SLOTTING FIXTUEE.
Fig. 366 shows three views of a simple slotting fixture which
was used to advantage for milling the slots T T in the cast-
ing shown. There were about 200 of these castings, and they
were required to interchange. Before slotting they were bored
and reamed at X X and the hubs were faced. The slotting
fixture consists of a machine-steel plate into which the cen-
tral locating-stud is riveted ; and two dowel-pins are let into the
back, as shown. These pins coincide with two holes drilled in
the stationary jaw of the miller-vise. A gauge-pin in the
front of the plate, at the right, serves to locate the work as
required.
INTERCHANGEABLE MANUFACTURING.
315
KEY-SEATING IN THE POWER- PRESS.
Fig. 367 shows the method used for cutting a keyway in the
small cast-iron collar at D. These collars were used in a large
number ; for that reason the means shown
were adopted for cutting the keyway.
The broach is fastened in a holder, while
the collar A is located beneath the stripper
of the die-bolster. The stripper and lo-
cating depression are cut away at the
front for facing and moving the work.
The guide is of tool steel, hardened, and
fits the circular portion of the broach
snugly. The finishing of the keyways
in the power-press by the means shown
fig. 367. proved very satisfactory, far more so
than by the old way of forcing the broach through under the
arbor-press.
HAND CUT-OFF AND FORMING-TOOL.
The tool here shown in Fig. 368 was used for the rapid pro-
duction of small work as sketched in W, Fig. 271, forming and
cutting off at the same time. As a rule, all work of this kind
is done in a turret-lathe or screw-machine. Pieces of the first
shape shown in Fig. 373 were produced by the present simple de-
vice at the rate of 8, 000 a day.
The tool was composed of two main parts, A the body, Fig.
269, and B the slide or tool-holder, Fig. 270. Having been planed
on the various sides it was set up and dovetailed for B to an an-
gle of eight degrees with the bottom. A hole was then bored and
reamed at E for the bushing, and hole D tapped for the set-screw.
A rib was cast up from the base and a hole drilled and tapped
through its entire length at C for the adjustable stop - screw H.
A hole was also cut through the bottom at P as clearance for the
lower handle T. The slide or tool-holder B of cast-iron was then
machined and fitted to the dovetail in A so as to run freely ; a
recess was also let in at J for locatiug the tool or cutter. A flat
316
TOOL-MAKING AND
piece of machine steel, D, fastened by the two screws as shown,
served as strap for holding the tool. A bushing of tool steel E
was then finished to the size of the stock to be used and fitted
tightly within A. This was cut away in front for clearance for
the tool and left full in the back to steady the side. This was
then hardened and slightly drawn. A stop -screw -ST was then
made which consisted of a long threaded stem to fit the hole ; the
head was large enough in diameter to serve as an adjustable stop
for regulating the length of the work. The forming and cutting-
off tool C was made, hardened and drawn, and fitted and held on
B as shown ; its cutting-face, when the side was advanced, coin-
ciding with the centre of the hole in the bushing E. The oper-
A -4M
1-iQl-
/■:'
^Sss^^
Fig. 368.
ating lever T was then made, the lug J fitting within the hole in
the slide B, the fulcrum of the lever being held between the two
lugs projecting down from the bottom of A. A hole was then
drilled in it for the adjusting-screw or stop A to prevent the tool
from going too far. Two stiff pull-springs A A were fastened
by pins in A and B respectively, with sufficient tension to bring
the slide back when the pressure on the lever was released. The
INTERCHANGEABLE MANUFACTURING.
317
parts were then assembled in the way shown. The rod used
came in 20-foot lengths, one end of which entered the hollow
spindle of the speed -lathe and was allowed to project from the
jL
v^
o
Wttftt
p
o
Fig. 369.
chuck almost four feet. This end was entered within the bush-
ing E ; the lathe was run at its highest speed and the tool held
in both hands. Pressing on the handle, the slide B moved far
enough to enable the tool C to form and finish the first end. The
~ i! "i~
Side of Slider B
K
"XT
j
m b
JDji
Plan of B
Fig. 370.
Q 1
l
A
5
?
roperly and as-
sists in driving it while the surfaces K and L are being ma-
chined. Two set-screws equipped with brass ends are used at M
to secure the stem in the chuck.
The next operation on the cams is the milling to size of the
342
TOOL-MAKING AND
portion indicated at N. For this a simple little device (not
shown) in the form of an angle -iron with a seat upon which to
clamp the machined portion of the cam is used.
For the third operation, which is the last, the chuck shown in
Fig. 410 is used. As will be seen, this is of much the same de-
FlG. 410.
sign as the other, except that it is equipped with a " locator "
which fits the milled channel N. Two set-screws fasten the work
in the chuck.
- It is obvious that with these two chucks the production of
cams that are interchangeable is not difficult, and at the same
time it is possible to machine them rapidly.
FIXTUEE FOE CHUCKING GASOLINE-ENGINE
CYLINDEES.
The chuck shown in Figs. 411 to 413 contains some points of
interest that may be adapted to the rapid production of any work
of a character similar to the pieces for which the fixture was de-
signed. The casting for holding which this chuck was made
was, as will be seen, of rather unusual shape. It formed a triple
cylinder for a high-speed automobile engine which was being
manufactured in large numbers. It had three cylinders B B B,
which were required to be bored out and reamed to size at C,
turned on the outside at E, and counterbored and tapped for
plugs at D. The portion indicated by the letter A was the hub.
The centres of all three cylinders had to be on the same plane
and spaced so as to form exactly the same angle with each other.
INTEBGHANGEABLE MANUFA CTUBING.
343
The construction and use of the chuck will be seen by refer-
ence to the three views shown in the illustration. G is a face-
plate, turned and finished to screw on to the lathe spindle and
channeled down the face to allow of locating the angle-plate H,
which was fastened to it by the cap -screws A" A A. The hub of
the casting was first held in another chuck and bored out on the
inside and finished on the outside to gauge. This preliminary
work formed the basis for the accurate accomplishment of all the
succeeding operations. The work was then located centrally
FIG. 411.
on a boss F formed upon the bracket H so that the three cylin-
ders would come approximately central. For clamping, the three
straps N N N were used ; while the indexing was accomplished
by plug A, Fig. 412, whose locating part was hardened and
ground to fit the finished bore of the cylinder, and also the
reamed hole in the lug J.
When using the chuck, a casting was first clamped somewhat
loosely upon the angle-plate H, being located centrally by the
stud F. A plug, which for a distance along its length fitted
the reamed hole in the lug J and for the rest of its length fitted
344
TOOL-MAKING AND
the cored holes in the cylinders loosely, was inserted, through the
lug, into one of the cylinders. The clamps were then tightened
Fig. 412.
and the machining proceeded. First the outside of the cylinder
was turned at E E to gauge, after which the steady rest was
FIG. 413.
brought up and adjusted so that the finished portion ran true
within it. This was followed by the boring and reaming, which
INTERCHANGEABLE MANUFACTURING.
345
was done by first using a bar with an inserted cutter, then a
shell-rose reamer, and* finally a one-bladed reamer for finishing.
After reaming, the counterboring and tapping were done. Now
the clamps were loosened and slid back, the work removed from
the angle-plate — the temporary plug having, of course, been first
removed — and the casting relocated with the finishing-cylinder
in line with the lug J. The plug K was then inserted, through
the lug, into this cylinder, which it fitted perfectly. The set-
screw M was tightened, thereby holding the plug securely in
place, after which the clamps were secured and the second cylin-
der was bored, reamed, counterbored, and tapped as had been
done with the first. After this the same method of procedure
was followed for finishing the third, or remaining, cylinder.
SPECIAL MILLING- AND DBILLING-JIGS.
Fig. 414 shows a casting which formed part of a clutch for a
perforating machine. The jigs shown in Figs. 415, 416, 417, and
418 were used in its production. The castings were 4^ inches
in diameter by 3^ inches long, with a cored hole in the centre.
Fig. 414.
The work to be done consisted, first, of boring and reaming the
hole A A to 2 inches, facing both sides, turning the outside, and
cutting in the groove E E. For this plain lathe no fixtures were
necessary. The further operations required were: Boring the
hole B for the sliding clutch-pin, milling the slot D D for the
feather C, and drilling the hole F.
For drilling the hole B the jig Fig. 415 was used. The cast-
iron body or base is machined on the bottom to bolt on to the
table of the drill -press. This body casting has a stem projecting
up from the centre which is turned to fit the hole A A in the
346
TOOL-MAKING AND
work, and is tapped at the top to admit the bushing-plate clamp-
ing-screws. There is a machined seat for the work to locate On.
The body of each clamping-screw enters the locatiug-stem for
a certain distance to insure the locating of the centre of the
hole B.
The milling of the slot D D in the casting and the drilling
of the hole F were accomplished by the jig shown in Figs. 416,
mi
_j
i i
JU
_L
. . ■.
c
FIG. 415.
417, and 418 ; Fig. 416 showing it as used for the milling of the
slot, and Figs. 417 and 418 when drilling the hole F.
The fixture consists of an angle-plate with a central locating-
stud fitting the centre hole of the work. This stud is tapped for
Front or Face View
FIG. 416.
the fastening -screw. To locate the work on the jig so that the
slot D D when milled will be properly located, the hole B in the
work is utilized, a steel pin in the jig fitting it. This pin is
made to fit the hole in the work and two holes in the fixture easily
to allow of its removal and re-use in locating the work in position
for drilling the hole F. To expedite the locating and fastening
INTERCHANGEABLE MANUFA CTV1UNG.
347
of the work on the fixture and its removal when milled a clamp-
ing-washer with a section cut out is used, thus allowing of merely
)-
Fir. 417.
loosening the screw and slipping out the washer when removing
the work. When in use the fixture is located on the miller-table
and held by two bolts, the tongue fitting the central groove of
the table.
The manner in which the hole F is drilled is clearly indicated
Fig. 418.
by Figs. 417 and 418. As will be seen, all that is necessary to
allow of using the fixture for this operation is the locating of the
348
TOOL-MAKING AND
stud in B and the locating and fastening of the bushing-plate
/ on the top of the body casting. G G are dowels, H a cap-
screw, and J a bushing. As the hole has only to run into the
centre bole A of the work, the presence of the screw W does not
interfere with the drilling. Although the fixtures are very
simple and inexpensive they are great labor savers.
A SET OF JIGS FOE MILLING AND DRILLING.
In Fig. 419 we have three views of a cast-iron punch-head
used on gang eyelet-perforating machines. These punch-heads
are required to be machined accurately so as to be interchange-
able, and are handled during the course of manufacture entirely
by jigs. While the work done by the use of these jigs is very
accurate and is accomplished rapidly, none of them are intricate
or expensive. The piece shown is about ten inches long over all.
Gib
Side |^«
M
D
© v
Fig. 419.
The punch-head consists (not counting screws) of four parts:
The head proper, of cast-iron; the back-plate V, of machine
steel ; the punch-key I, of brass ; and the gib at C, of machine
steel. Leaving the smaller parts, we will take up the machining
of the head proper.
The work required to be done on the punch-head consists of
milling all sides square and true, milling the dovetail B B and
the gib-way G, milling the angular-formed face D D, drilling
and reaming the long central hole E E, drilling four holes H for
fastening the back-plate, two holes fou fastening the brass key,
one hole for the gib-tightening screw F and another clearance-
hole for the gib -pin G.
INTERCHANGEABLE MANUFACTURING.
349
The castings for the heads before machining were square all
over except for the dovetailed and gib surfaces, which were
roughly cast.
The first operation was accomplished ou a large milling-ma-
chine by means of a supply fixture, and a large inserted tooth-
milling cutter handling ten castings at a time. This fixture is
not illustrated.
For milling the dovetail and gib- way the jig Fig. 420 was
used. This accommodated eight castings. The work is located
Fig. 420.
on a machined seat. P P are the side-locatings, L L the lugs for
the side-fastening screws, and A the projection in which the end-
fastening screws are located. With this jig the vertical milling
The Wcrfc
Fig. 421.
Fig. 422.
attachment was used. First the dovetailed slideway was ma-
chined with an angular cutter, taking two cuts, one at each side ;
then the gib-way -C was machined by substituting a suitable cut-
ter for the angular one. As all the surfaces of the castings were
perfectly square and to size, the milling in this operation was
done very rapidly.
350
TOOL-MAKING AND
The milling of the inclined formed face D D of the castings
was done by handling one casting at a time in the jig Figs. 421
and 422. The amount of material removed in this operation is
indicated by the dotted lines. A large formed milling-cntter was
used for this work.
Operation fourth was the drilling of all the holes in the head
casting. This drilling was done before milling the keyway for
the brass key, because the long central hole H H had to be per-
fectly straight and reamed to size.
Fig. 423 is a plan partly in section of the jig. It is of the
box type with cast legs L on four sides. The work is located by
Fig. 423.
means of the dovetailed locator N N on a machined seat in the
bottom of the jig, and is secured by means of a swinging strap,
not shown, hinged at Xand fastened at Z by a thumb-screw.
The locator N N is of machine steel, fastened to the inside of the
jig side by two dowels C. The bushings for drilling the long
hole are removable. They are notched at the side for the
knurled-head locating-pins R, which prevent them from turning
or falling out. The hole II H is drilled from both ends, half
way from each. When reaming, the two-drill bushings are re-
placed by others. One at the bottom fits the reamer, while the
upper one fits the stem. In reaming this hole a shell reamer re-
versed is used, so that the cutting-end is upward and the hole is
reamed from the bottom.
For milling the cross-slot or keyway, the jig shown in Fig.
424 was used. This was made to hold a number of castings at
INTERCHANGEABLE MA NUFA CTUBING.
351
ouce. The work is located and fastened positively and with ease,
and its removal when finished is quickly accomplished. The
clamp shown at the front end is so made as to allow of locating
Fig. 424.
it quickly by means of the small latch P which is hinged in the
clamp at K. By simply pressing back the handle of this latch
the clamp is released and may be
slid off.
By reverting to Fig. 419 the
machining required for the small
parts will be understood. First,
we have the back -plate V. This
is of machine steel and is first
milled and squared all over, the
milling of the formed edge to co-
incide with the formed face D D
of the imuch-head being done after
the drilling of the four screw-
holes. Then we have the brass
" key. " This is cut from the bar
and cleaned up to size. The drill-
ing of the two holes It in the brass
key and the four J in the back-
plate are all done in the one drill-
ing-jig, Fig. 425. The jig is made
to accommodate a plate at one
end and a brass key at the other.
The body casting is machined so
as to leave locating-seats for the
work and with a channel across
it for the piece against which the work locates. The bush-
ing-plate is fastened to the body by four flat-head screws.
Fig. 425.
352
TOOL-MAKING AND
S S 8 S are the plate-drill bushings and T T the key-drill bush-
ings. MM are the jig legs cast on. the body. Q and R are two
screws for fastening the work on and against the locating sur-
faces. The work is slipped in at the ends ; then the screws are
tightened and the holes are drilled.
The remaining piece shown in Fig. 419 is the gib. This has
a pin which is grooved out at one side to coincide with the taper-
point of the gib-screw F. When the screw is tightened it forces
the gib in and thus clamps the head in position on the perfo rat-
ing-machine. This gib is of machine steel and is milled to size
in the miller-vise, an angular cutter being used to taper the
edge. For drilling the hole for the pin L a simple little slip-jig
is used.
The tools shown possess no novel features, nor are they of in-
tricate construction. However, they are interesting and should
prove suggestive for other work, as they illustrate how accurate
repetition work may be done rapidly and cheaply if some thought
is given to the devising of simple and inexpensive tools.
FACING AND COUNTEEBOEING LARGE SPIDEE
CASTINGS IN THE DEILL-PEESS.
In a shop where paint-mixing machines are built the writer
came across a method of facing and counterboring large castings
Fig. 426.
in the drill-press which may prove suggestive to readers for the
machining of other work in a like manner. An idea of the shape
and size of the castings may be gained from Fig. 426, in which is
INTERCHANGEABLE MANUFA CTURING.
353
shown the nature of the work to be done. As will be seen, the
casting has two hubs which are required to be bored to a finished
diameter of five inches, then faced at A A, B B, C C, and I) D
respectively, and, lastly, counterbored at F F to a depth of one
inch and a diameter of seven inches. It is at once obvious that
the large drill -press which is equipped with a floor base is the
proper machine for the work, and that it would be very difficult
to do the work in any other machine.
The boring to a finish of the cored holes in the hubs presented
no unusual difficulties; a large boring-bar of approved construc-
tion being used and the projecting end allowed to run in a bush-
ing bolted to the floor base of the drill, to which the work was
Fig. 427.
strapped. To accomplish the facing of the four hub faces and
the counterboring of the seat in an expeditious and accurate
manner, however, required other means than those used for the
boring. It was for this work that the special facing and
counterboring tool illustrated in Fig. 427 was used.
As will be seen, the special tool consists of the regulation bar,
turned taper at one end to fit the drill-press spindle, and rounded
at the other to enter easily the supporting bashing on the base
of the press. This bar has five holes let though it to accommo-
date the boring-head. The holes are indicated in the engravings
by letters C I) E and F respectively. Three holes are for the
cutter-bar and the other two are tapj)ed holes for the feed-screw
G. In the cutter-head, H is tie bar, the " goose-neck ;J cut-
ting-tool, a seat for which is provided in the cutter-clamps M at
23
354 TOOL-MAKING.
either side of the centre as the taking of under and upper cuts
necessitates. I is the connecting strap between the cutter-bar
and the feed-screw, J the bar-fastening nut ; G the feed-screw
and -ST the hand knob. JV"is a cap-screw used for fastening the
cutter and cutter-straps to the cutter-bar.
In using this tool the bar was projected down through the
hubs of the casting until the end ran in the supporting bushing
at the base. The cutter-head was then in the position shown in
Fig. 427. First the surface A was faced, the feed-screw being
turned a little by hand at each revolution— the large opening-
making this an easy matter. Next the seat F F was bored and
finished in the same manner, feeding the spindle of the drill
down for depth and the feed-screw of the cutting-head for diam-
eter. After this the under face of the upper hub was faced by
removing the cutter-head entirely; feeding the spindle down-
ward until the upper three holes in the bar were clear of the
under face of the upper hub; then relocating the cutter-head
with the feed-screw in the same hole as it occupied in the first
instance; but with the cutter-bar in the upper hole C. Thus
the cutter-bar was merely reversed and the facing of the under
side of the hub accomplished by feeding the spindle up instead
of down. The two faces of the lower hub were faced in the
same manner, the cutter-head being removed and reversed as
required.
CHAPTER XXIII.
Special Machines for Accurate Work on Dies ; *
Their Use.
PROGRESS MADE Ils T THE USE OF POWER-
PRESSES.
It must be gratifying to mechanics who are interested in the
cheap and accurate production of metal parts to note the won-
derful progress that has been made in the use of the power-press
during the last few years. In fact, the time has arrived when
this modern machine has demonstrated its efficiency, when used
in conjunction with suitable dies and fixtures, for producing
parts of steel, iron, and other metals at a lower cost to the manu-
facturers and to a finer degree of interchangeability than it has-
heretofore been possible to attain by other means.
Where the power-press has been adopted for the production
of metal parts, and where the full value of dies is understood
and appreciated, the machines in which they are used have be-
come as important factors in production as any of the other
machine tools in general use. The only reason for their non-
adaptation in other establishments, is that their use is not under-
stood. There are a great number of shops, both large and small,
in which duplicate small parts of standard shapes and sizes are
being constantly made, by milling, drilling, filing, or other
means, that could be produced at a greatly reduced cost and to a
higher degree of accuracy by means of suitable dies iu the foot-
or power-press. In such shops, the use of the product of dies,
that is, using sheet-metal blanks instead of castings where prac-
ticable, would cause the people who are responsible for results in
such shops to first open their eyes and later to double their pro-
duction and profits.
355
556
TOOL-MAKING AND
HAND-FINISHING VS. MACHINE-FINISHING OF
DIES.
While numbers of special machines and devices have been
invented for the making of all kinds of other tools, hand-work,
to a greater or less degree, has been depended upon for the mak-
ing of dies, from the simple blanking type to combinations of
the tools. The advent of the vertical attachment for the univer-
sal milling-machine helped some ; but what was wanted was a
machine which would do the work which it was then only possi-
ble to accomplish by the hand of a skilled mechanic with a file.
Thus, to a certain extent, the use of dies has been prevented by
the expense which would be incurred in the making of them.
This excuse, however, is now no longer operative, for there are
FIG. 428.
now machines which will do the work on dies formerly only pos-
sible by hand labor. I refer to the various die-shaping and mill-
ing-machines which are now on the market.
The value of these machines to all concerns in which many
dies are made may be judged from Fig. 42S, in which are shown
a number of dies of different types which were machined and
finished, up to the point of hardeniug, by the use of a die-mill-
ing machine. Every die-maker knows the skill necessary for
finishing such dies by hand, especially in giving the proper or
INTERCHANGEABLE MANUFACTURING. 357
required degree of clearance all the way through. By the use
of machines of the type mentioned above, this can be accom-
plished with ease ; and dies which are required to be straight, or
tapered slightly inward, as is necessary in burnishing-dies, may
be finished with no more trouble than would be involved in the
finishing of a die with excess clearance.
USE OF DIE-MILLING MACHINES.
The die-milling machine may be used for roughing out and
finishing, to within a thousandth of an iuch or so of the templet
lines, any kind of blanking-, trimming-, or pnnching-dies, such as
are required to produce silverware, jewelry, bicycle parts, drop-
forgings, typewriter parts, sewing-machine parts, etc.
A type of die-milling machine now in use in a number of die-
shops is so constructed that the frame of the machine is sup-
ported on trunnions, or gudgeons, which hold it in any desired
positiou, so that the operator may have the best possible light on
the surface of the work. The spindle is perpendicular to the
machine face and is adjustable. When arranged for milling
blanking-dies the cutter projects through an opening in the
chuck in which the work is clamped, and is straight or tapered
to suit the amount of clearance required in the die. When such
machines are used it is only necessary to drill one hole through
the die-blank, and the cutter, starting in this hole and following
the outline of the templet, removes the entire centre in a single
piece. The chuck, or work-holder, on such machines is moved
in either direction by means of two slides at right angles to each
other and, by the use of hand-wheels on the feed-screws, the out-
lines of the templet on the surface of the work are accurately fol-
lowed. To assist in doing this there is a pointer at the right of
the work which remains at a fixed position with reference to the
cutter when the latter is below the surface of the work, and indi-
cates its exact position. This is a convenience in cases where a
sharp corner is to be made, when the cutter can be lowered and
the cutting continued, guided by the pointer, thus leaving very
little to be filed.
Although die-milling machines are not built usually to take
358 TOOL-MAKING AND
very large work, they will take blanks or forgings up to ten
inches wide by two inches thick and any length.
DIE-SINKING ATTACHMENT.
In connection with machines for die-making, a die-sinking at-
tachment may be used, and if a great number of dies are required
to be sunk, one of them is worth having. By the use of the die-
sinking attachment, the skill and knowledge necessary to the suc-
cessful use of small chisels, gravers, riffles, and other tools of the
hand-die sinker, are not absolutely .necessary, and a good die-
maker will have no difficulty in doing the best work in this
line. As these attachments can be attached to die-milling ma-
chines in a few minutes, the machine is converted into a die-
sinking machine.
MACHINE FOE FILING DIES.
In a number of shops known to the author they have also a
special machine for filing the dies worked out in the die-milling
machine. This machine is used for filing to a finish all kinds of
blanking-, trimming-, punching-, and irregular or square-shaped
drawing dies, or anything of that kind that has to be filed accu-
rately.
By adjusting the table of this machine to a graduated plate,
any desired clearance from one to ten degrees can be obtained.
By setting the machine at zero, the walls of a drawing-die, a
burnishing -die, or an accurate trimming-die can be filed or lapped
perfectly square, something that is impossible by hand, even by
the most skilful die-maker. In these filing machines care must
always be taken to have the upper end of the file supported by ad-
justing a rest provided for that purpose. The amount of stroke
in machines of this kind can be readily adjusted by a slot-headed
screw in the driving- disc, carrying it further from or closer to
the centre, as the work may require. For fine filing a short
stroke is desirable.
The samples of die work shown in Fig. 428 are only a few of
the large variety of dies which can be finished in half the time
and at half the expense usually required when other means are
INTERCHANGEABLE MANUFACTURING. 359
used. Although it is a fact that skilful workmen cau often ac-
complish the most astonishing results with tools which are far
from being what they should be, an equipment of up-to-date tools
is always to be desired in any line of mechanical work.
A DIE-SHAPEE.
The line drawing (Fig. 429) shows in use a device which prac-
tically converts a milling-machine into a vertical shaper, or, as
Fig. 429.
usually miscalled, a slottiug-machine. It is especially service-
able in working out dies for punching-presses, following any out-
line, regular or irregular, and giving the required clearance all
around. As will be seen, the attachment may be used upon any
milling-machine of the standard type, and when once fitted may
be slipped on or off as required.
360 TOOL-MAKING AND
The large vertical casting seen in front clamps on to the over-
hanging arm of the machine, and a spindle below is driven by
a taper-shank which fits the machine spindle. Between the two
bearings which are provided for this spindle it has secured to it
an eccentric or cam which operates a horizontally sliding block
which works in the cross-slot of a vertical slide carrying the cut-
ting-tool. The vertical stroke obtained is \\ to If inches, as de-
sired. The cutting-tool is made of ^-inch round steel, secured
in the socket by a set-screw. This tool socket is separate from
the vertical slide, and when the tool is set it may be turned
around as required, so that any outline may be followed and all
corners may be worked into. A clapper-block has been pro-
vided which gives perfect clearance for the tool on the up-stroke.
The drawing shows the tool at work upon a half -die of irregu-
lar outline. This die is mounted upon a tilting-chuck which ac-
companies the attachment and provides the necessary clearance-
angle for die work.
It will be noticed that the middle face between the rings is
oblique and by turning these the pitch is thrown in the different
directions required, a locking-pin, a clamping-screw and a bar
for turning the rings being provided. The central post has a
spherical head, so that it can incline as the angle requires.
A SMALL DIE-SLOTTEE.
The machine shown in Fig. 430 is suitable for all such work
as small key-seating, die-slotting, both straight and taper; also
internal or external gear patterns where draft is required, and
all that class of common slotting shown in Fig. 431.
The two cross motions and the rotary table provide for fol-
lowing any outline.
The handle for the rotary table is arranged for using dials for
dividing purposes, but for small divisions and rapid work it may
be entirely removed, and the table revolved by hand, using the
locating device, which provides twelve divisions for square, hex-
agon, octagon, etc.
The stroke of the machine has been fixed at 24- inches, which
is ample for the class of work for which the machine is intended,
and affords greater strengtli than an adjustable pin.
INTEECHA NGEABLE MANUFA CTTJRING.
361
The speed can be changed by means of the cone pulley.
The slide for the ram can be swiveled five degrees either way
and set by a graduated index, thereby insuring the same draft
to every part of the die. The tool-
block is well adapted for holding spe-
cial tools. It swivels in a centre near-
its lower end, and at the upper end,
carried in a yoke, are two hardened
plugs which bear on a cam that is
bushed into the lower end of the con-
necting rod, and from it derives a par-
FiG. 430.
Fig. 431.
tially rotary motion, thus locking the tool-block on the down
stroke and causing the tool to clear on the up strokes.
A DIE-FILING MACHINE.
The die-filing machine illustrated in Figs. 433, 434, and 435,
while being designed particularly for die-making, is now in use
in many of the best-equipped factories in this country at a variety
of other work.
A great deal of metal pattern work may be done on this ma-
chine at a great saving of expense. Hardened dies, gauges, etc. ,
may be lapped much faster and truer than by hand. A variety
of small parts too delicate to be milled may be filed accurately
aud economically. It is also well adapted to making a great
many templets aud forming-tools.
362
TOOL-MAKING AND
In the following pages I illustrate a few ways in which the
filing machine is adapted to die -making and in which it has
proved itself a success by actual use in various tool-rooms where
it has been installed.
In filing dies by hand as per Fig. 432 a man must work in a
cramped position where the light is often very poor and where
Fig. 432.
the lines to which he is working are generally on the side away
from the source of light. He must watch the lines and keep his
surface flat and true, while all the time exerting no small amount
of strength.
Under these conditions die-making requires a very high-
priced man and he must spend a good part of the time in testing
the accuracy of the work and in resting.
With the filing machine the work is flat on the table with the
lines in plain view and where it will obtain the best possible light.
The correct amount of clearance or angle is accurately ob-
tained, and the file moving in an absolutely straight line gives
a true, flat surface with no rounded edges. Thus the operator,
as shown in Fig. 435, is relieved of these details and may devote
his attention solely to guiding the work.
INTERCHANGEABLE MANUFA CTUEING.
363
The machine does the hard work, and the operator is in a
comfortable position and able to do more and better work.
The cut Fig. 433 shows the machine sawing out a die. In a
variety of dies the lines are straight or nearly so, and an ordi-
Fig. 433.
nary 6-, 7- or 8-inch blade may be used, sawing very close to the
lines, giving the proper shear by tilting the table, and leaving
very little filing to be done.
For smaller work a narrow blade may be used which may be
turned in small circles ; there can be had a 4-inch blade y s ¥ -inch
wide with wide kerf for this work.
In cut Fig. 434 is shown the manner of using large files for
Fig. 434.
roughing. The file is clamped rigidly at both ends and the work
held against it with the feed-screw and guided by hand.
The file moving straight up and down gives no chance of
rounded edges and the stock may be removed very fast.
Fig. 435 shows the method of finishing small work with small
files. The file is held in the lower clamp only, the upper clamp
364
TOOL-MAKING.
removed, leaving the work free to be taken out and examined
at will without disturbing the file. The file clamps are made to
take any file from the smallest up to ^-inch thick. Saws are in-
stantly adjusted on pins on the file clamps.
File clears on the return stroke in either direction. Clear-
ance is provided for the file whereby it is held clear from the
work on the return stroke. The file may be made to cut on
FIG. 435.
either the up or down stroke by changing the crank-pin to the
opposite end of the crank-arm. The amount of clearance is ad-
justable from -^ to by means of a knurled-headed screw at the
front of the frame.
Tilting table. Graduated readings are provided by which the
machine can be set at any angle with mechanical exactness.
Files a straight and true surface.
Feeding. A screw feed, operated by hand, is provided, by
which the work can be fed to the file in any direction on the
table.
An adjustable strap is provided to hold the work down to the
table. This is especially useful in sawing and heavy filing.
An air-pump is provided to blow away the chips and filings,
by which the work and file are kept clean, insuring a smooth cut.
Four changes of speed are provided : from 60 to 450 revo-
lutions.
CHAPTER XXIV.
The Art of Working Sheet Metals in Dies and
Presses.
USE OF SHEET METAL IN PLACE OF OTHER
MATERIALS.
The marked progress that has been made in the art of sheet-
metal working and that made in the use of the power-press for
the cheap and accurate production of large and small, plain and
ornamental sheet-metal parts, during the last decade, has led to
the use of sheet metal as a material in the construction of many
articles and appliances formerly made from other materials.
Dies, operated by presses — power, foot, hydraulic, and hand —
do a stupendous share of the work of manufacturing metal goods,
from the small trouser button to the massive boiler head. Not
only are these tools vised for the simpler operations required in
the cutting out of irregular shapes cheaply and accurately, but
for bending, twisting, drawing, embossing, and forging opera-
tions as well.
As an instance of what is being accomplished along the line
of sheet-metal working in dies, I may state that in the sample
room of the great press and die works of E. W. Bliss Com-
pany, of Brooklyn, N. Y., may be seen samples ranging all the
way from an aluminum mandolin body to a full-size sheet-metal
barrel, and from sheet-metal sinks and boiler heads to aluminum
automobile bodies.
Next to a thorough understanding and appreciation of the
power-press as a machine tool, a practical understanding of the
most approved methods -and processes for the economic produc-
tion of sheet-metal parts and articles in it is most necessary to
those engaged in the working of sheet metals. Although the
number of establishments where sheet metal is worked in dies is
great,, there are many where the most approved processes are not
315
366 TOOL-MAKING AND
known, or the proper construction of the tools is not understood.
In such works the interdiction to the rapid and accurate produc-
tion of new and unusual shaped articles lies in those responsible
for results not being familiar with the construction and use of
suitable tools.
SIMPLEST CLASS OF PRESS TOOLS.
The simplest class of tools used in the power press are those
for ordinary bending. In this class of punches and dies it is
necessary to combine simplicity with durability and cheapness ;
and one of the things to be prized is an ability to devise simple
and effective means for producing in the fewest number of opera-
tions the articles required, and constructing the tools so as to
allow of being set up and operated by unskilled help. Very
often it is possible to design a die that will accomplish in one
operation that which usually requires two or more to -produce,
being, of course, of a more complicated and accurate construc-
tion and requiring more skill and intelligence to operate. On
the contrary, though, it is often preferable to increase the num-
ber of operations — by adopting simpler methods — in dies that
will stand rough usage. The nature of the work and the quan-
tity of parts required should determine this.
"GANG "AND "FOLLOW" DIES.
For the production of small sheet-metal articles which are re-
quired to be pierced, bent, formed or stamped at one or more
points, the dies should be, whenever possible, of the "gang" or
" follow " types ; that is, tools in which gangs of punches and
dies are assembled and located so that results desired in the fin-
ished blank will be accomplished progressively in one operation.
It is only by the use of such dies that small sheet- metal articles
can be produced in large quantities at a profit. All too fre-
quently dies of the plain or "single " type are used, and three or
more sets of them are required, when the same results could be
accomplished in one operation if the proper attention were given
to the devising of suitable tools. Wheu sheet-metal articles are
required in large quantities an operation saved means a great
INTERCHANGEABLE MANVFAGTUBING. 367
deal ; and if two operations can be saved even at the outlay of
considerable money and time, the results attained will more than
compensate for all.
PIERCING OR PERFORATING DIES.
The construction of punches and dies for piercing or perforat-
ing sheet metal is comparatively simple and no very intricate
methods are involved. Their construction is usually similar to
that of the "gang" type, and they are used for operations on
work ranging all the way from ornamental thin sheet-metal arti
cles to the punching of holes in steel beams and boiler plates.
The holes pierced may be of any shape and spaced as desired.
Often a number of small blanks are produced at each stroke of
the press by dies of this class ; a sheet of metal of the required
width being fed to the dies automatically. Perforated sheets of
different metals are now in great demand and are used for a
variety of purposes too numerous to mention.
PROCESSES FOR DRAWN WORK.
For the production of drawn and formed shells from sheet
metal, the dies in general use consist of four distinct types. The
first and most primitive method consists of punching out the
blank to the desired shape and size in a plain blanking die, and
the pushing it through the drawing die, or dies, according to the
desired length of the shell. This manner of producing shells is
the cheapest only where a small quantity is desired. The second
method is by the use of compound dies and the double-acting
press, in which the blanking punch descends and punches out
the blank, and then remains stationary while the shell is being
drawn and formed by the internal drawing punch. The third
method is by means of a punch and die of the combination type,
in which the punching and drawing dies are combined and are
used in a single-acting press. This method is by far the most
popular and generally used one, as well as the most practical for
the pro ( duction of plain or fancy drawn shells which are not re-
quired to exceed one inch in height. The design and method of
constructing dies of the combination type differ according to con-
368 TOOL-MAKING AND
ditions; but the fundamental principles involved are substan-
tially the same in all of them, and may be adapted for the pro-
duction of drawn shells of any shape which it is possible to
produce in one operation in a single-acting press. The fourth
and last method of drawing shells is by means of triple-acting
drawing dies; they are used to produce shells which are required
to be blanked, drawn, embossed, lettered, paneled, in one opera-
tion; and are used in triple-acting presses.
Farther on in this work all the different types of dies used
for the production of drawn sheet-metal work are fully illustrated
and the most approved methods of constructing them exhaust-
ively described.
DEPTH WHICH MAY BE DEAWN IN SHEET METAL.
The depth which may be drawn in sheet metal in one opera-
tion is usually equal to about one -half the diameter for small
cups, and one-third for large vessels.
Where a depth greater than can be drawn in one operation is
required, it is necessary to accomplish the job in two or more
operations ; drawing a larger and shallower shape first, and after-
ward reducing the shell to the desired size and shape.
ANNEALING AND LUBKICATING IN DBA WING.
In deep drawn work the edge becomes irregular, and requires
trimming before finishing the piece. It is also necessary in such
work, or in other cases where the metal is severely worked, to
anneal the metal during the processes ; but tin-plate is ruined by
annealing ; hence such work is drawn and annealed before plat-
ing, or if some stiffness is required in the finished articles, one
drawing operation may be performed after annealing and plating.
When drawing bright steel it is necessary to use oil as a lubri-
cant, and apply it in spots over the sheets before they are worked
up. In working tin-plate the coating of tin, together with the
thin film of oil left on it from tinning, are ordinarily sufficient
lubricant; but in drawing large pieces in a double-acting press a
stick of paraffin wax may be passed once around the edges of the
blanks.
INTERCHANGEABLE MANUFACTURING. 369
THE DBA WING AND FORMING OF DECORATED
SHEET-METAL ARTICLES.
By far the greatest development in dies for the drawing of
sheet metal has been along the line of decorated tin boxes. The
fundamental practical points to be kept in mind when construct-
ing dies for working such stock are as follows: Make three tem-
plets — one for the drawing die, another for the drawing punch,
and a third for the corners, so as to get them the proper radius.
Finish the drawing die, the punch plate, the two sides of the
blank-holder ring and the inside of it, and the drawing die, be-
fore starting on the cutting die or punch. Then make your trial
draws until the proper blank is found. When the exact blank
has been found, finish the cutting die and the outside of the
blank-holder ring, and fit the blanking punch. Take a cut off
the die base after the die has been hardened — this base should
be, of course, of mild steel. For decorated metal allow about
.006-inch clearance in the drawing die; that is, finish the draw-
ing die .006-inch and two thicknesses of metal larger than the
drawing punch; while for plain tin allow about. 0035-inch clear-
ance in the drawing die. By giving this clearance there will be
no necessity for easing up with files or scraping or grinding, and
the designs on the metal will not be marred or scratched. Round
the edges of the drawing die smoothly ; if the draw is very short,
-^ inch will be enough, and if long, increase it accordingly. Be
careful to get all the corners of the drawing punch the same
radius and those in the die also (plus two thicknesses of metal
and the clearance) and lap very smooth. By keeping the fore-
going points in mind no trouble will be encountered when con-
structing a die of this type or in using it either.
"FINDING" THE BLANKS FROM WHICH TO DRAW
SHELLS.
The finding of the proper size blank for drawn shells is
usually a troublesome matter ; however, the way to figure out the
approximate size of a blank for a straight cylindrical shell is as
follows : Take the outside diameter of the shell to be drawn and
24
370 TOOL-MAKING.
add to it the length or depth of same. Then add to this ^ inch
for every f inch of depth, and the resulting total will be very
near the exact size of the required blank. For deep shells this
rule will allow of finding a blank which, when the shell is drawn,
will leave enough for trimming ; while for shallow depths, which
will draw perfectly straight across the top, a slight reduction in
size will be necessary. The amount to deduct will become ap-
parent after the first trial draw.
There are any number of rules for figuring the side of blanks,
in which the principle upon which the finding of the diameter is
based is that the area of a drawn shell equals the area of the
blank from which it is drawn. But as this is never the case, be-
cause of the fact that all metals stretch and run unevenly under
drawing pressure, the rules work well only on paper. The way
to construct a drawing die in the shortest possible time is to
figure out the approximate size of the blank in the manner de-
scribed in the foregoing ; cut out and file up a templet according
to the result ; make the drawing portions of the die ; make the
trial draws ; discover where there is an excess or a deficiency of
metal ; make a new templet, which should be almost perfect,
draw it up, and if found correct finish the cutting portions of the
die.
CHAPTER XXV.
The Making and Use of Punches and Dies for Sheet-
Metal "Working.
Having in the preceding chapter presented the fundamental
principles and practical points which are necessary for the tool-
maker to know in order to construct and use dies successfully, I
will devote this chapter to describing and illustrating the various
types of dies in general use. The designs have been selected as
representing the most advanced practice in the best shops, and
may be adopted, with slight modifications, in dies for the pro-
duction of sheet-metal parts and articles in endless varieties.
The number of dies shown in this chapter and the one follow-
ing is sufficiently large, and the variety representative enough,
to allow of the reader comprehending all types. When, in the
case of the descriptions, it has been found expeditious to de-
scribe means and ways for constructing, this has been done. In
fact I have adopted this method all through the book ; for I do
not think it is enough merely to illustrate the tool ; the mechanic
is also interested in the manner in which it should be made and
how the desired results may be accomplished.
THE MAKING AND USE OF SIMPLE DIES.
I will first show and describe a number of dies that are in-
valuable for use in the average machine-shop, especially the job-
bing tool-shop. The dies shown are the most .simple and inex-
pensive of their class for work of the kind shown. Fig. 436 is
known best among die-makers as an emergency die — that is, a
punch and die for producing a small number of blanks of a given
shape and size, of which the blank X is an example.
The die A consists of a piece of y'yinch fiat tool steel, planed
and fitted to the bolster, with the shape of the blank worked out
at B B. In dies of this kind, when only a small quantity of
371
372
TOOL-MAKING AND
blanks are to be punched, the clearance or taper of the die from
the cutting -edge is considerable, as the more clearance given the
less work and skill required to finish, allowing the blank just to
fit at the cutting-edge. This die is hardened and drawn. For
the punch a cast-iron holder C is turned and finished and faced
flat and smooth on the front. The punch D consists simply of
a piece of ^-inch flat tool steel worked out and sheared through
the die and left soft. It is then hard-soldered to the face of the
holder C. For punching blanks from thin sheet metal to the
number of 10,000, this die is all right. Although some may say
Fig. 436.
"a botch job," the results will be found to be all that is required.
This style of die is used universally in almost all of the fancy
sheet-metal goods houses, as the number of different shapes, and
the small quantities required, necessitate the elimination of all
unnecessary expense.
The die shown in Fig. 437 is known as a shearing or finish-
ing die for heavy blanks and is used for finishing work such as
is often done in the milling-machine, or grinder. The blank Z,
as will be seen, is a small handle punched from -g^-inch mild
steel. In punching for heavy blanks the punch is always fitted
very loosely to the die, and the blank produced is generally con-
cave at the edges, and has a ragged appearance where it has cut
INTERCHANGEABLE MANVFA CT URING.
373
away from the rest of the stock. To remove these defects and
marks, the blank is sheared through the finishing die, Fig. 437,
when trimming or cutting off a shaving of stock all around, the
blank leaves it smooth and has an appearance of having been
milled. In making dies of this kind one of the blanks that have
been punched is taken and filed and finished all a*round the edges,
removing about .003-inch of stock all around. The blank is then
used as a templet for finishing the die, letting it through from
the back aod filing the die straight, with just the slightest amount
r^i
Punch
Blank-
JL'
9-,
D
Fig. 437.
of clearance, being sure to have the blank a good fit at the cut-
ting-edge. The inside of the die is then finished and polished as
smooth as possible at G and then filed taper downward from H.
I is the gauge plate which is worked out and finished to allow
the rough blank to fit nicely within it, The plate is fastened to
the face of the die by the screw J and the dowels K, so that the
blank will rest on the face of the die I with an equal margin all
around for trimming. Great care should be taken in adjusting
this gauge plate to its proper position, as the small amount of
stock to be trimmed will not allow much leeway. The die is
374
TOOL-MAKING AND
hardened and drawn to a light straw color and the face is ground
and oil -stoned, leaving it as sharp as possible. The punch is
constructed in the regular way and fastened within the pad, as
shown. The punch is sheared through the die and left a snug
fit within it, after which it is highly polished and finished and
left soft. In use, the blank Z is placed within the gauge plate I,
and, the punch descending, it is sheared into the die at G, trim-
ming and finishing it all around, and, if the die has been pol-
FlG. 439.
Fig. 438.
Fig. 440.
ished, leaving a nice smooth finish, producing as good a job as
could be done more expensively in a miller. A large number of
different small pieces in demand in the average machine-shop,
when the quantity permits, could be finished at a greatly reduced
expense by this means.
When a nice polish or finish is desired on the work the blank
is forced through a second die, which is relatively the same as the
one shown in Fig. 437, except that it tapers slightly from the
cutting-edge, being about .002 inch smaller at the back than at
the cutting-edge. This die is also highly polished and finished,
and left very hard. By being forced through the die, the metal
around the edge is slightly compressed, and polished by the fric-
tion. I have seen blanks treated in this manner that had all the
appearance of having been polished or buffed. This die is
known as a burnishing die, and is excellent for quick and cheap
production.
The punch and die shown in Fig. 438, although of the simplest
design, form a great tool for accomplishing by inexpensive means
INTERCHANGEABLE MANUFACTURING. 375
results that generally involve considerable time and cost. The
die shown is for finishing square holes after the first operation,
and T the appearance after being finished. Of course they could
be finished by broaching, but the punch shown is the better
method. After the holes have been blanked they are ragged and
uneven at the edges. They are also left undersize about .003
inch.
The punch 8 is first finished on the miller to a perfect square
of the size required — that is, .003 larger than the blanked hole.
After being polished, the face is finished dead square and the
edges are left sharp. The punch is then hardened and slightly
drawn. The die P is then made and worked out until the point
of the punch can be entered, and then, using it as a broach, forc-
ing it into and through the die, leaving it an exact duplicate of
its shape. The die is then filed taper from the back, leaving it
straight about ^ inch from the face, as shown at P. After the
holes for the dowel and stripper screws are let in, the die is pol-
ished, hardened, and drawn slightly. The edges of the end of
the punch 8 are then ground and rounded, so as to enter the hole
in the stock easily. The stripper Q consists of a piece of ^ -inch
flat machine steel with a channel milled down through the centre,
in depth and width sufficient to allow the strip of steel within
which the holes are punched to pass through it freely without
side play. A small pin projecting above the face of the die P
at the left side acts as a gauge for locating the holes true with
the die. The punch and the die being set up, the strip is in-
serted within the gauge or stripper plate Q with the first hole
under the punch. The punch, descending and entering the hole,
gradually compresses the metal and finishes it, leaving a dead
square hole with a nice smooth finish on all sides. The punch
shown should enter the work for a full inch of its length. This
style of die can be used for finishing a large variety of differ-
ent shaped holes in heavy iron or mild steel, where they are
all required to be of the same size and shape; also leaving
a finish that it would be impractical to accomplish by other
means.
376
TOOL-MAKING AND
PUNCHING BRASS CLOCK GEARS— MOVABLE STRIP-
PING DEVICES.
The gear shown in Fig. 441 was produced complete from
^-inch-thick sheet brass. Holes were required to be punched at
A, B and C, five sections D cut away, the centre hole punched,
and the teeth cut. The gear was required to be perfectly true
with the centre hole and to balance evenly.
A cross-section of the punch and die is shown in Fig. 442,
with a plan of the die in Fig. 443. Three successive operations
produce the gear. The three holes A, B and C and the large
FIG. 441.
centre hole are pierced in the dies at the first stroke, the sections
D are punched out at the second, and at the third stroke a fin-
ished gear is cut out. Hardened and ground bushings are used
for the dies h, d and m to allow of easy repairing.
It is in the die X X that unusual conditions are met. This
die, used for punching the sections D, is made in two parts, al-
though this might not appear necessary to some. The work to
be done, however, in this die was of such a character that satis-
factory results would have been impossible with a solid die.
The " spider " used in this die is shown as located and fastened
in position in Fig. 443, and in detail in Fig. 444. As shown,
there are five arms Z and a hole at Y. The outside of the wings
INTERCHANGEABLE MANUFA CTUBING.
377
are turned taper, large at the back and smaller at the cutting
face. The spider was left large all over and hardened and drawn
to a light straw. It was then chncked and the hole Y was lapped
to the size of the hole in the gear, after which the spider was
forced on a mandrel and ground all over to size, which was, to
Fig. 443.
say the least, a very nice job. The portion X X in the die plate
was bored taper, and five shallow channels K were cut into its
walls, as locating seats for the wings Z of the spider.
The blanking die W, in which the gear teeth are cut and the
finished piece is produced, was finished by reversing the usual
378
TOOL-MAKING AND
method ; that is, instead of shearing the punch through the die
the die was broached by the punch. As will be seen in Fig. 442,
this punch is finished with a stem F to fit a hole in the machine -
steel holder E and has a hole straight through it for the pilot
pin N. The teeth in the punch were milled and finished in the
same manner as a gear would be, getting as smooth a finish as
Fig. Ui.
Fig. 415.
possible. The punch was hardened and drawn slightly, after
which the face was ground and stoned keen. The die W was
then finished by using the punch as a broach. The die plate V
was hardened and ground. Then the punch L was re-annealed
and sheared into and through the die. Thus a perfect fit was
attained. The punch was left soft.
The centre piercing punch T is in one piece and is let into a
counterbored seat J in the holder. The other three piercing
punches for the holes A, B and C, Fig. 441, are of drill rod, and
are located in strong supplementary holders, as shown at H, 8
and K.
The punch (or punches) for cutting the sections D in Fig.
441 is shown at Q Q in Fig. 442, and a plan or face view of it in
Fig. 445. P is the pilot pin. The punches Q form parts of the
solid piece and were not hardened ; as if they had been the
resulting distortion woidd have made a fit within the die X X
and the spider Z impossible. As it was, by shearing the sections
Q into the die and leaving them soft, no difficulty was expe-
rienced getting a close fit at all points.
The only part requiring further description is the stripper,
which is of unusual construction. As shown in Fig. 442 it is
INTERCHANGEABLE MANUFACTURING. 379
located on the punch, or "male" die. It comprises a flat mild-
steel plate T, fitting around the punches proper, two blocks of
hard-spring rubber U U, one located between the stripping-
plate and the punch-holder face at each end, and four studs of
the usual construction, not shown. One of these studs is located
at each of the four corners, with the heads let into counterbored
holes in the back of the holder and the ends screwed into the
stripping-plate. No other springs were required, as the rubber
blocks answered for that purpose.
SPEING STEIPPEES.
Although a great many die-makers claim that spring strippers
located on the punch should not be used where a stationary strip-
per can be located on a die, still there is a large variety of work
for the production of which a movable stripper must be used if
accurate results are to be obtained.
It is well known that punching or perforating dies having
stationary strippers will distort the plates or articles punched by
them, and often to such an extent as to require subsequent
straightening. Thus, where accurate parts, such as are used for
clocks, electric instruments, etc., are produced in gang dies, the
distortion of the metal as it is worked upon by the various
punches, will, when stationary strippers are used, prevent the
production of satisfactory work. On the other hand, where
movable strippers (any of the various types I mean, and not
merely the one shown here) are used, a clear space is left be-
tween the punches and dies, enabling the operator to manipulate
and observe his work quickly and accurately. The stripper
comes down on the strip first, straightening and clamping it
before the punches enter, while the pilot jfins locate the various
operations positively. The metal is held under pressure while
the punching and stripping are being done, and by this means
the work comes out perfectly straight and true. Where a num-
ber of small perforating punches are required, they may be made,
with the use of the movable stripper, much shorter than a station-
ary stripper would permit. At the same time a smaller hole, in
proportion to the thickness of the stock, may be pierced because
380
TOOL-MAKING AND
of the close support which the movable stripper (when well
fitted) gives to the punches up to the point where they enter
the stock.
PUNCH AND DIE FOE END FINISHING, CUTTING
OFF AND BENDING SHEET METAL FEOM THE
STRIP WITHOUT WASTE.
Up at the left in Fig. 446 is shown, somewhat enlarged, the
piece made by the punch and die (Figs. 446 and 447). These
Oage find
Stripper
Stock t " ■' ..■■■'■^■| i
lax
I I • I
W • (£
Stripper aud / Dte
/ (gstopf
— ^a )
PIG. 446.
articles are manufactured by the million and are used as protec-
tive seals for wooden boxes and cases, their use preventing the
usual loss from theft while cases of goods are in transit. They
were produced in one operation, without waste, from •yL-inch-
thick cold-rolled stock of the required width ; and the efficiency
INTERCHANGEABLE MANUFA CT UBING.
381
of the die can be appreciated from the fact that it produced
215,000 of the articles shown without grinding.
Fig. 446 is a plan of the punch, a side view of both punch
and die, and a plan of the die without the stripping arrange-
ments; while Pig. 447 is an end view of the tools, with the
stripper and the inclined fork for operating it in position. The
.
i
i
-3>
1
~\
O
1
1
1
Fig. 447.
punch consists of the usual cast-iron holder and tool-steel punch.
The punch is finished at one end to act as the cutting-off and
end-finishing punch, and in the centre as the bending die, the
half -circular groove in the top being let in for the clearance for
the stripper pin (see Fig. 447). The punch is hardened and
drawn to a dark straw temper.
The die consists of a flat cast-iron bolster into which the cut-
ting-off and end-finishing die and the bending punch are located
in dovetailed channels and fastened by flat-head screws let in
from the bottom of the bolster. The adjustable stop plate also
382
TOOL-MAKING AND
is fastened to the bolster. The stripper arid gauge combined
consists of a piece of ^-inch stock with a channel cut down
through one side wide enough to allow the stock to be fed
through it easily, but without side play. It is fastened to the
face of the euttiug-off die by four round-head screws, as shown
in the plan. As shown in the section of the die, the beudiug
punch has a half-round groove let into the face to correspond
with the other half in the bending-die portion of the cutting-off
punch. The cutting-off die and the bending punch are hardened
and drawn to a light straw, after which the sides of the bending
punch are eased off a bit toward the bottom, so that the metal,
when bent, will cling to it instead of to the bending portion of
the cutting-off punch.
The stripping arrangements, as shown in Fig. 447, consists of
the following parts : The stripper proper is a round stud let into
a small casting located in the dovetailed channel for the bending
punch in the bolster. This stud has a pin let through the back
end to prevent it from springing out too far, when the punch is
up, by the action of the spring at the back. A stronger pin is
let through the enlarged portion or collar of the stud, so that the
inclined fork, which is fastened to the back of the punch -holder,
will, while descending, move the stripping-stud back and off the
face of the bending punch.
When the die is in use, a strip of metal is entered beneath the
gauge plate and is allowed to project a slight distance beyond the
Fig. 448.
cutting die. The press is stepped and the end of the stock is
trimmed and finished to the shape shown in the plan of the die.
The stock is then moved forward against the stop, and, as the
punch descends, the piece is cut off and bent over the bending
INTERCHANGEABLE MANUFACTURING. 383
punch, the cutting punch descending about f inch below the cut-
ting-edge of the die. As the punch ascends, the inclined fork
releases the stripping-stud which springs outward and throws the
finished piece off the bending punch and iuto a box at the front
of the press. The parts are thus produced without waste and as
rapidly as the stock can be fed. At first strips of metal were
used in the die, but after a short time rolls of the required width
with 200 feet of stock in each were used. They were placed on
a reel at the left of the press and the stock was fed automatic-
ally, through a pair of straightening rolls.
TWO DIES FOE METAL BOX-COENEE FASTEXEES.
The article shown in Fig. 448 is a sheet-metal trunk corner.
These corners are made flat, and are intended to be bent at right
angles after one end is nailed on to the trunk. The notches on
the sides serve as guides for nailing the corner in the proper
position, and they also facilitate the bending. The corner is so
made that the edges bind the wood closely when nailed on, thus
making a very rigid corner.
Two operations are necessary. The first, that of notching and
cutting off the blanks, is done by the punch and die shown in
Fig. 449, showing a section of the punch and die and a plan of
the die. There are three punches fastened in a machine-steel pad,
which is in turn fastened to the face of the holder by six flat-head
screws. The end-notching and cutting- off punch is at the right,
and is about -£% inch shorter than the centre notching punch at
the left. This is so that the centre notching will have been ac-
complished before the blank is cut off.
The die is made in the regular way, with two short gauge
plates at the right end, and with the stripper extending entirely
across the face of the die. When the blank is cut off it drops
off at the back, as the press is inclined and there is no gauge
plate to hinder it.
For the finishing operation — that of drawing and forming the
six raised spots and perforating them in the centre — the punch
and die, Fig. 450, are used. The punch is in a dovetailed
channel in the holder and fastened to the bolster by two flat
384
TOOL-MAKING AND
screws let in through the bottom. The dies proper are six tool-
steel bushings, finished on the face with a forming tool to the
shape required, and a small hole let down through the centre.
They are hardened and forced into counterbored holes in the die
plate. The die plate is beveled at the edges to correspond with
,osition on the press bolster and the
lower plunger. Fig. 487 is the upper or punch portion. In Fig.
486 A is the press bolster, B the raised or bridge bolster on which
the cutting and drawing die J is fastened, and D the lower
plunger with the embossing die M.
The cutting and drawing die J is in one piece. It was a forg-
ing of mild-steel base and a tool-steel face for the cutting and
drawing portions. F is the cutting-edge, sheared as shown at
G ; H the surface on which the blank is held while being drawn ;
J the drawing-die portion, and X the stripping edge. The die
is fastened to the face of the bridge bolster by the cap-screw K.
L is a clearance hole in the bridge bolster. The embossing die is
Fig. 485.
INTERCHANGEABLE MANUFA GTUBING.
411
secured to the face of the lower plunger by the two screws 0.
N shows the embossing face of the die.
Iu the upper part of the punch part, Fig. 487, Q is the com-
Fig. 486.
bined drawing and embossing punch, and P the cutting punch
and blank-holder, which locates on the face of the outer ram of
the triple-action press at S and is
fastened to it by the cap-screws
through T. The combined cutting
punch and blank-holder was a
forging of mild-steel back and tool-
steel face, while the drawing and
embossing punch was drawn and
worked out of a round length of
annealed tool steel. It is secured
in the inner ram by a key through
the taper slot.
It will be understood that very
accurate work was necessary in
making the tools and that all
working parts were hardened,
drawn, ground, and lapped to a
dead finish in order to have the
work come out as required.
The manner in which the tools were used to produce the shell
was as follows :
FIG. 487.
412 TOOL-MAKING AND
The lower die being fastened to the face of the plunger D and
the upper die with the bridge bolster to the face of the press
bolster, the combined cutting punch and blank-holder Pis located
on the face of the outer rani and the combined drawing and em-
bossing punch in the inner ram. The strokes of the two upper
rams of the press are then adjusted, and the lower one on which
the embossing die is located is adjusted to almost meet the face
of the embossing punch Q on its up -stroke. All is then ready.
The combined cutting punch and blank-holder Pis worked down-
ward by the outer ram of the press, and travels slightly in ad-
vance of the drawing and embossing punch Q which is actuated
by the inner slide, the outer slide of the press being so adjusted
that after its stroke has been made it stops during about one-
quarter of the rotation of the crank-shaft. The blank is cut out
from the sheet and held between the annular pressure surfaces,
if of the die and P of the punch, during the down " dwell" of
the outer slide. Now, while the blank is held under pressure —
which has been regulated to suit the special requirements of the
metal to be drawn — the drawing and embossing punch Q con-
tinues to descend, draws the metal from between the blank-hold-
ing surfaces, and draws it into and through the die at I, the
drawing and embossing punch continuing to descend until the
shell has been drawn completely through the drawing die, carry-
ing it down uutil its lower surface meets the face N of the em-
bossing die — which corresponds in its function to the solid bottom
in double-action dies — mounted on plunger D working in sleeve C
on its up -stroke. It is actuated by arrangements at the side of the
press, motion being communicated through cams on the end of the
crank-shaft. Here the shell receives on its face the impression of
the design shown in Fig. 485. On the up-stroke the finished article
is stripped from the punch Q by the stripping edge X, and, the
press being inclined, the work slides off at the back.
It is surprising how much fine work can be got out of a
triple-action die in a day of ten hours, and it would pay any
manufacturer who has work of the kind shown here to do in
large quantities, to adopt dies of this construction, as any of his
double-action presses can be arranged for them at a small cost
compared with the increased output.
INTERCHANGEABLE MANUFACTURING. 413
In regard to the making of the dies, I might state that they
are easier to construct than those of the single-action combina-
tion type which are most frequently used for such work. There
are fewer parts to the triple-action dies than to the others, and
there is less liability of their getting out of order, while the
hardening of the working parts can be done with the assurance
of success, and the grinding and lapping of the hardened parts
to the finish sizes afterward can be done with ease. In order
not to leave any marks on the outside of the shell when drawing
aluminum, it will be found well to lap the drawing die after
grinding with a lap actuated in the direction of the working
movement.
I neglected to state that it was necessary to lubricate the
aluminum sheets before working, but as the cleaning of the cov-
ers afterward would have cost more than the making of them,
and as the preparation which was to fill the boxes was such as to
require the entire elimination of oil on the metal, we had to be
very careful in lubricating the sheets so as to get a sufficiently
thin coating on them to allow of its being taken up in the work-
ing of the metal. This was successfully accomplished by coat-
ing one sheet thickly with melted Eussian tallow and running it
through a pair of rolls, after which a number of other sheets
were run through and coated evenly and thinly. The oil disap-
peared entirely during the blanking and drawing of the shell.
The cover was. 3^ inches in diameter, 1 inch high; was
punched from stock slightly over -fa inch thick and required a
blank 4'ff- inches in diameter, which left just the narrowest pos-
sible margin for trimming.
BLANKING AND DRAWING AN ALUMINUM SHELL.
Not very long ago I had a set of dies to make for the produc-
tion of an aluminum box, and as it was necessary to construct
the tools so that the articles might be produced at the minimum
of cost, I adopted dies which would allow of producing a cover
and a box complete at each stroke of the press ; that is, one die
for the cover and another for the body of the box. These dies
were of the combination cutting and drawing type, in which the
414
TOOL-MAKING AND
blank is first cut and then field between the annular pressure
surfaces of tfie puncfi and blank-fiolder ring wfiile it is being
drawn up into tfie puncfi. Tfie sfiell as drawn to form tfie body
of tfie box, and tfie die used for it are sfiown in Fig. 488.
As I fiave been in a number of sfiops wfiere tfiey use two dies
to accomplisfi results wfiicfi are attained in tfiis one, and as tfie
FIG. 488.
construction and action of tfiese dies are by no means well known,
a sfiort description of it may be of interest.
Fig. 488 shows a longitudinal cross-section of tfie die com-
plete as it appears wfien set in tfie press and ready for work.
A A is tfie cutting-die, a forging of mild steel witfi a tool-steel
face to act as tfie cutting-edge ; G is tfie drawing puncfi, wfiicfi
INTERCHANGEABLE MANUFACTURING. 415
is located in the cutting-die by being screwed into a set at E E ;
D is the spring-pressure attachment plate, to which the cutting
die is bolted by bolts 0; P P are two of the six tension pins
which support the blank-holder ring B B and communicate the
tension from the rubber spring barrel L. The spring-barrel at-
tachment consists of the stud N which is screwed into a tapped
hole Jin the plate I) D, the two cast-iron washers A' K, and
the rubber spring barrel L. This rubber spring barrel is usually
about 3^ inches in diameter and 6 inches long, for drawing all
shells up to one inch in depth. M is the nut for adjusting the
pressure in the blank while it is being drawn up into the punch.
In the punch or upper section of the die, F Fis the combined
cutting punch and drawing die. It is a forging of mild steel
with a tool -steel ring welded on to act as the cutting and draw-
ing face. II is the drawing-die portion of this punch, G the
spring pad which expels the shell after it is drawn, and J the
adjusting nut for the spring pads. In a die of this kind the
cutting punch, drawing pad, blank-holder ring, and cutting
die are all hardened and tempered, the cutting-edges being
drawn to a dark straw and the drawing portions to a light straw
temper.
In using a punch and die of this kind the die is first set up
on the press bolster and the plate I) D bolted to same. The
punch is then located in the ram of the press and aligned with
the die. After this the stroke of the press is set so that the
punch will descend the proper distance, the pressure of the
spring buffer is regulated, and we are ready to proceed. A sheet
of stock is entered to rest on top of the cutting-die and the press
stopped. As the press descends, the cutting-edges punch the
blank into the cutting die A A, where it is held between the faces
of the punch and the blank -holder ring jB B, and as the punch
continues to descend the drawing punch G draws the metal up
into the cutting punch and from between the pressure surfaces,
the metal being held tight enough to prevent inceptive wrinkles
and crimps from forming. As the punch rises the sheet of stock
is stripped from it by bent pins placed around the cutting-die,
and the finished shell is expelled from the inside by the spring
pad being actuated by a knock-out in the press body. When
416 TOOL-MAKING AND
a die of this kind is used to an inclined press the finished shell
falls off through gravity at the back.
Combination cutting and drawing dies of the construction
shown and described here may be used to the best advantage for
the production of shells from stock as thin as paper up to \ inch
thick. They may be used in either single-acting foot or power
presses. In most cases the shells produced in dies of this kind
are of shallow shapes, their edges frequently not being over
-3L- inch deep, as for instance, can tops and bottoms, pail, bucket
and cup bottoms, etc. On the other hand, however, dies of this
class can be used for the production of much deeper articles,
such as boxes and covers for blacking, lard, salve, and other
goods up to f inch deep, or for cutting and drawing burner and
gas-fixture parts, toys, etc., up to 1 inch in depth. However,
the best results will be secured in the drawiug of shells which
will not exceed f inch in length, as in order to draw that depth
the rubber spring barrel has to compress to its maximum, and to
compress it more would cause the metal either to stretch exceed-
ingly or to split. When it is desired to draw shells over f- inch
in depth it will be found better to use two dies, a combination
die and a re-drawing or finishing "push -through" die.
As the die shown here was for cutting and drawing alumi-
num, it may be well to assure my readers that no difficulty was
experienced, notwithstanding that the tools were made the same
as for working brass. The precaution necessary, however, to
assure satisfactory results was the use of a proper lubricant,
which was a cheap grade of vaseline. For deep draws in this
metal use lard oil.
A NICE JOB OF BENDING AND FOBMING.
Fig. 489 shows the blank to form Fig. 491. This blank was
7 inches long by 2\ inches wide, and was of hard brass -^ inch
thick. The corners were to be sheared to the radius shown,
three holes were to be pierced at each end, and a slot was to be
punched in the centre.
It was considered more economical to shear the strips of
stock to the required width. The tools, Fig. 492, were of the
INTERCHANGEABLE MAN UFA CTURING.
417
"gang" type, performing the operations on the blank success-
ively, and lastly cutting off the piece to the required length. In
the die section V V indicate two of the piercing dies. They are
o
p
>
o
The Bl'ank
o
u
o
FiG
489.
hardened and ground steel bushings let into counterbored seats
in the cast-iron die-block. X is the slotting die located in a
channel in the face of the die-block by means of a strong dowel
-After First Bending Operation
Fig. 491.
at Y. Z is the corner-trimming and cutting-off die, located in
the die-block in the same manner as the die T. The gauge-plate
extends along the entire length of the die, while the stripping
g g
Plan of Punch
r 'fn'zll I W^^l
J '. ■■','■■■ .;':/,..» :.. 1 !■'■ ■■..■//>■:■>.■>/■*/.
FIG. 492.
arrangement consists of four straps fastened by round -head
screws T. By making the die in this way any injured part
could be taken out and replaced independently.
The punch consists of a cast-iron holder in which are located
27
418
TOOL-MAKING AND
all of the small punches, five of which are fastened in their coun-
terbored seats by means of set-screws J, while the inner central
one is fastened by a flat-head screw let in from the back of the
holder. The slotting punch M is located in a square channel in
the holder by dowel and two flat-head screws JV N. The
trimming and cutting-off punch is located in the same manner in
channel Q Q by dowel B and screws 8 8.
The slotting punch M is the longest, while the cutting-off
punch is the shortest. This is so that, the stock being fed from
left to right, the slotting punch will pierce the stock first and
PLAN
OF
PUNCH
FIG. 493.
locate it while the six holes are being pierced, and the cutting-off
punch will not commence to cut until all other punches have
entered their dies. Thus the accurate sizing of the blanks arid
the location of the various operations is assured. With this die
an adjustable stop, not shown, was used.
The result of the first bending operation on the blank is shown
in Fig. 490, and to perform it the tools shown in Fig. 493 were
used. The sketches are so clear that very little description will
be necessary. The punch-holder is of cast iron dovetailed on
the face at K K for the punch of tool steel, which is worked out
INTERCHANGEABLE MANUFA GTTJBING.
419
to the shape shown and hardened at the bending face. The
locater and the spring arrangement are self-explanatory. The
die also is of tool steel and is machined to fit the bolster and has
a tapped hole at W for fastening screw. P P indicate the blank
in position for forming, while the dotted lines V V indicate it as
formed into the die. S'S are the side gauges and T the end
locating point. In use, the press in which the dies were located
was inclined, and the work after bending fell off at the back.
For the last operation in the production of Fig. 491 the very
simple tools illustrated in Fig. 494 were used. The work before
finishing is indicated by the dark portion in position on the
Fig. 494.
locater L, while the dotted lines P P show it as finished. The
punch, of tool steel, is machined to fit the dovetailed channel in
the face of the holder (not shown) and at J J to fit the central
formed section of the work ; the die is of cast iron.
The rapidity with which these two bending dies can be
worked and the quality of the work done by them are surprising
when the simplicity and cheapness of the tools are considered.
Some may think that it would have been better to have designed
a die which would do all the bending in one operation. Possi-
bly, if a sufficient quantity of the articles were required — say
several millions.
420
TOOL-MAKING AND
"GANG" PUNCH AND DIE FOE PEODUCING
EYELETS IN ONE OPEEATION.
As an example of what is being accomplished in the devising
of means for the production of sheet-metal articles in one opera-
tion I illustrate and describe here a "gang" die of very interest-
ing type. A number of these dies were designed and put into
successful operation by the writer not long ago for the produc-
FlG. 495.
tion of one of two parts of a metallic button. They will be
found the best to adopt' *f or the manufacture of small buttons,
eyelets, shell rivets, and anything of like nature that it is neces-
sary to produce cheaply and in large quantities. To secure the
minimum cost of operation, the stock is usually fed automatic-
ally by means of a fine-tooth ratchet roll-feed, thus securing fine
adjustment of the stroke.
In brass work, where we can get our stock in long lengths,
or in rolls approximately uniform in width, a die of the type
shown in Fig. 495 will run off the entire strip or roll without the
INTERCHANGEABLE MANUFACTURING. 421
possibility of error, thus allowing of the press attendant looking
after several presses and keeping them running continually.
Now, in the first place, be it understood that in order to draw
sheet metal into any form or shape, it is first necessary to pro-
vide a blank. And when the article drawn is produced progres-
FiG. 496.
sively, as in the die here shown, it is necessary, first, to cut the
blank partty from the strip so that it may decrease in diameter
with the drawing in such a manner as in no way to disturb the
relative distance between the centres of the different operations
required to produce the shell. This is the point which many
die-makers forget, so that the dies prove defective where means
are not provided for first partly cutting the blank, and there is
no possibility of locating the successive operations in their
proper positions, because of the metal which goes to form the
cup being drawn sidewise and lengthwise in the first drawing.
And as this will continue with each draw, .there will be no likeli-
hood of accurately locating the different operations. The way
in which a "gang" die of this kind should be made in order to
attain the desired results, will become apparent to the practical
reader in the description of the tools here shown.
The punch and die were used to produce small shells like the
one shown at the upper right of Fig. 495. And it required seven
workings to produce the shell, finishing it complete from flat
stock at the rate of 40, 000 to 50, 000 per day of ten hours. The
stock used was . 030 soft brass.
As the illustrations of the die and punch show clearly the
various parts used in the construction of the tools, and Fig. 496
the results accomplished at each operation in the progress of the
strip across the die face, very little description will be necessary.
The stock is first cut as indicated at A, Fig. 496, by punch J,
Fig. 495, and then at B by punch K. Thus, the blank is pro-
duced so as to remain attached to the strip and to allow of being
drawn and decreased in diameter by the subsequent operations
422 TOOL-MAKING AND
without affecting the position of its centre in relation to the
strip. This will allow of the metal being drawn into the shell
and still leave a margin to hold the cups together and allow of
feeding them along for the next operation.
The stems of the seven punches J KL M N and P are let into
reamed holes in the holder I and are fastened with set-screws,
not shown. The punches were all hardened, drawn, and care-
fully lapped to size and shape. The die is finished in the usual
manner, formed counterbores being used to finish the drawing
and sizing dies. Q is the first cutting die, R the second, 8 the
first drawing die, T the second, 77 the third, and V the sizing
and finishing drawing die, while W is the blanking and trimming-
die. Each of the drawing dies is furnished with a plunger,
which is hardened and drawn and let into pad Y. These plun-
gers serve the double purpose of holding the metal while being
drawn and of stripping it from the dies afterward, thereby leav-
ing the stock free to be fed forward to receive the next opera-
tion. A channel planed lengthwise in the bolster A- A at Z
allows the pad Y to work up and down with the action of the
press ram. The two springs B-B B-B keep the plungers up with
sufficient tension to hold the metal securely between their faces
and the faces of the drawing punches while the drawing and
reducing are being accomplished. Their pressure is adjusted or
regulated by the headless screws D-D D-D. The trimming or
blanking punch P has a pilot pin which fits the last drawing
snugly and locates it true and central for being trimmed and
blanked clean off the strip.
As the results accomplished by the use of such tools as are
herein described and illustrated would require three or more
operations if the simpler tools were used, it is no hard matter to
figure out what the saving is.
In conclusion I might state that there is any variety of small
drawn, formed, or embossed sheet metal work that could be pro-
duced more accurately and in half the time by the use of just
such dies as that shown here. In order to succeed with these
tools, however, always remember, before attempting to draw and
form cups progressively from the strip, to provide means for
partly cutting the blanks from which to draw the cups.
INTERCHANGEABLE MANUFACTURING.
423
COMPOUND DIES FOR PARTS OF TELEPHONE
TRANSMITTER CASES.
FIG. 497.
In Fig. 497 are shown the assembled parts of a telephone
transmitter case of sheet metal, and in Figs. 498 to 503 the dies
used .for producing the parts. It is needless to state that these
cases are used in great quantities and that the dies for their pro-
duction are required to be of the
most accurate and lasting con-
struction in order that the parts
may be produced rapidly and in
exact duplication. As the work
involved in the production of the R
transmitter-case parts consists of
blanking, drawing, forming, pierc-
ing, and wiring, the dies are in-
teresting, and engravings of them,
together with the description of
their construction and operation,
will prove suggestive in the adoption of similar tools for the
production of a large variety of drawn sheet-metal work, accu-
rately and economically.
As will be seen from Fig. 497, the case consists of three parts,
designated 1, 2, and 3, respectively. The part 1 is of an artistic
shape and represents a nice job in drawn work. The die used
for producing it is shown in Fig. 498 and was, as were all the
blanking and drawing dies used in the production of the case
parts, of the compound double-action type of construction. As
a great many tool-makers are not familiar with drawing dies of
this type, a slight description of their use will contribute to an
intelligent understanding of their making.
Double-action dies derive their name from the fact that they
are used in double -action presses to cut a blank and at the same
stroke draw it into shape without the help of springs or buffers,
as in the case combination single-action dies. The kind and
thickness of the metal used determine whether one or several
operations will be necessary to obtain the desired shape and
424
TOOL-MAKING AND
depth in the article. There are two essentially different types
of double-action dies, viz., Fig. 498 is a "solid -bottom die," and
Fig. 501 a "push-through die." However, they are both used
in the same way.
Taking the die Fig. 498 — which was used for producing the
part 1 of Fig. 497 — G is the die bolster, in which the drawing
and blanking dies are located. It will be understood that all
parts of this die had to be constructed very accurately, that the
working x>arts were hardened, drawn, and ground and lapped
smooth in order to produce the parts as required. In the die, A
Fig. 498.
is the main drawing die, which is located in a taper seat in the
bolster, while F F is the blanking die, located in a seat in the
surface of the bolster and secured by means of the two fillister
head-screws H H. N is a stripper of the usual type.
In the punch section, L L is the combined cutting punch and
blank-holder ; a forging of mild steel with a tool-steel ring welded
on to oiie side to act as the cutting punch 1 1. It was machined
all over; being turned at J J to locate on the face of the outer
ram of the double-action press, and was hardened and drawn at
1 1 and then ground to fit the cutting die F F, after which the
INTERCHANGEABLE MANUFACTURING. 425
face was lapped so that the blank would be held evenly while
being drawn. B is the drawing and forming punch and E its
stem. The maimer in which this die was used, as well as the
other double-action dies shown here, will be understood from
the following :
The lower or die section G is fastened to the face of the press
bolster, while the combined cutting punch and blank-holder 1 1
is fastened to the face of the outer ram, and moves slightly in
advance of the drawing punch B, the stem A" of which is fastened
in the inner ram, by which it is actuated. The outer ram of the
Fig. 499.
double-action press being so arranged that, after making its-
stroke, its stops during about one-quarter revolution of the
crank-shaft, and the combined cutting punch and blank-holder
cuts the blank at F F, carries it down to the inner surface of the
cutting die ; holds it there tightly and remains stationary, hold-
ing it between the annular pressure surfaces of the punch and
E E during the down "dwell" of the outer slide.
While the blank is under a pressure which has been regulated
to suit the special requirements of the case, the drawing punch
B continues its downward movement, thus drawing the metal
from between the pressing surfaces into the shape required. As
the punch rises the combined blank-holder and cutting punch
remains stationary until the drawing punch has disappeared
within it ; then it rises also. At the completion of the up -stroke
a knock-out attached to the press actuates the die knock-out D
which delivers the finished shell at the top of the die. Some
426
TOOL-MAKING AND
very close work and careful grinding, lapping, and polishing
were necessary in order to get this die to produce part 1 as was
desired, the metal used being sheet brass y 1 ^ inch thick, the utmost
care being necessary to get the difference in the diameter and
curves and shape of the punch and die exactly two thicknesses
of metal.
The punch and die used for producing part 2 of Fig. 497 is
shown in Fig. 500. Although a compound double-action die, it
will be seen that it is constructed differently from the one shown
in Fig. 498, and that different results are accomplished in it. In
this die the shell, forming part 2 of Fig. 497, is blanked, drawn,
formed, and a hole pierced in the centre, to admit the end of part
3 as shown at a, Fig. 497, at one stroke of the press. However,
the use and operating of the die are the same as explained for the
first. As in the other, close and careful work were necessary
on all the parts in order to have the die work well in the press.
In the die section, B E is the cast-iron bolster, P P the combined
cutting and drawing die, and Q Q the combined bottom-forming
and hole-piercing die.
In the upper section of die, Fig. 500, W W is the combined
cutting punch and blank-holder, a forging T T the drawing and
forming punch, and Z7the hole-piercing punch. The manner in
INTERCHANGEABLE MANUFACTURING.
427
which the metal is cut, drawn, formed, and the hole pierced,
may be seen from the dark section. In this die the bottom-form-
ing and hole-piercing die Q Q also acts in the capacity of a
knock-out ; it being actuated on the up-stroke of the press rams by
the knock-out device attached to the press. The blank produced
by the hole-piercing punch U fiuds egress through an enlarged
hole running entirely through the stem of the piercing-die sec-
tion. Ideal results may be accomplished in a die of this con-
-struction, as the holding of the blank while it is being drawn is
perfect ; an even pressure being maintained all the time, which
is not the case when single-action combination dies are used, as
the tension on the blank is communicated through a rubber
spring barrel which compresses as the blank-holder ring de-
scends and thus renders the tension uneven. Thus, deep draws
Fig. 501.
cannot be attained in a single-action die through the metal tear- .
ing or splitting because of too much pressure on the blank as
the draw nears completion ; while in compound double-action or
triple-action dies, draws of considerable depth, in comparison
with the diameters, can be attained because the pressure on the
metal is exerted by cams on the crank -shaft and is, of course,
even.
To produce part 3 of the case, to the shape shown in Fig. 497,
three operations were necessary. The first consisted of drawing
428
TOOL-MAKING AND
a shell of the shape shown at the upper left of Fig. 501. This
shell was blanked and drawn in the double-action "push-
through " die shown in Fig. 501. As will be seen, the die sec-
tion is in one piece. It was a forging of mild steel at base, with a
tool -steel face for the cutting die. The weld of the two steels is
indicated by a wavy line in the drawing. The machining and
finishing of the die were accomplished in the usual manner; all
working parts being left over size, and ground and lapped to a
Fig. 502.
finish after the die had been hardened and tempered. A is the
base, C C the cutting die and blank-holder portion, D D the
drawing die, and B B the stripping edge.
In the punch section of Fig. 501, H is the combined cutting
punch and blank-holder and J the drawing punch. As will be
seen, the die is equipped with a stripper of the usual construc-
tion. This die was a far more rapid producer than the other
two, as the metal was cut, then drawn and pushed through the
INTERCHANGEABLE MANUFACTURING. 429
die, stripping at B B ; thus obviating the necessity of a knock-
out and the delivering of the drawn shell at the top of the die.
The second operation in the production of part 3 was accom-
plished by means of the tools shown in Fig. 502. These tools
require little description as their construction and use are al-
most evident at a glance. S is the punch -holder, P the drawing-
punch, and R its stem; while X is the inside blank-holder which
supports and holds the shell on the inside while it is being reduced
and formed; Q is the stripper. In the die, L is the bolster, M
the die, and iVthe knock-out for stripping the finished work from
the die. The punch and die were operated in a reducing press
with a stroke of considerable length.
The last operation in the production of part 3 consisted of
punching out the bottom at & & and wiring the edge at d d as
shown. This work was accomplished entirely by the use of
the combination wiring and piercing die shown in Fig. 503.
Although the drawing is very clear, a description may assist
many to understand intelligently the construction and working
of the tools.
In the lower section, T is a cast-iron bolster, bored out and
recessed for the hole-piercing die U Z7and the holder and locator
V V. The piercing die was of tool steel, hardened, ground, and
lapped to size, and a force-fit into its seat in the bolster, while
V V was of mild steel worked out on the inside to fit the formed
shells and turned taper on the outside to drive into the taper seat
in the bolster.
The upper section consists of, first, the holder B, a forging of
mild steel worked and machined as shown, to contain the wiring
die W W, the spring stripper and work supporter X X, and the
piercing punch T. As will be seen, the wiring die is located in
a seat in the holder-face and fastened by means of fillister head,
screws, while the piercing punch is located in a reamed hole run-
ning entirely through the holder, and is permanently secured in
position by means of a taper pin at A. The spring D D exerts
enough pressure on the combined work-supporter and stripper
X X to allow of it supporting the shell on the inside while it is
being wired by the die W W, and then stripping it from the
piercing punch at the rise of the press ram.
430
TOOL-MAKING AND
When the punch and die are in use, the shell is slipped into
the locating seat in V V and the press stepped. As the punch
descends, the supporter and stripper come in contact with the
inside of the shell and hold it tightly while the spring com-
presses and the rest of the punch parts continue to descend.
Then the edge of the shell enters the wiring groove and follows
around its curves ; the punch descending until the curl is com-
plete, the piercing punch T having meanwhile punched the bot-
tom out of the shell and into the die 77. At the up -stroke of the
ram the stripper X X remains stationary until the piercing punch
Fig. 503.
has left the shell and the wiring die has risen above it ; then it
rises also, leaving the finished shell in a position to be easily
removed.
The other operations necessary to allow of the parts of the
transmitter case being assembled as shown in Fig. 497 consisted
of joining parts 3 and 2 together as shown, and piercing four
holes in the rims of parts 1 and 2 for screws. But as the tools
used for those latter operations were very simple, their illustrat-
ing and describing are unnecessary.
In conclusion, I might state that it would be well for manu-
INTERCHANGEABLE MANUFACTURING. 431
facturers of artistic drawn sheet -metal articles and parts to give
more attention to the use of double-action dies and double-action
presses, as the results accomplished by their use are not to be
compared with those accomplished by combination dies in single-
action presses.
CHAPTER XXVII.
Processes, Presses, Devices, and Arrangements for
the Rapid and Economical Manufacture
of Sheet-Metal Articles.
PBESS WOEK.
It is only during the past few years that the use and value of
the power press and hydraulic press for sheet-metal working have
come to be almost universally appreciated and known, and to-day
the rapidity with which their use is being extended is astonishing.
Among the machine-tool brood the power press and its work
occupy a unique position in one respect,- as it is the only ma-
chine tool, and its operation involves the only process, in which,
after the material is once cut off from the sheet or bar, there is
no making of chips or waste. The press, as such, does neither
cutting or abrading.
To be sure, the power press is usually a more or less expen-
sive machine, and the devising and constructing of suitable dies
for it requires the employment of the most skilful mechanics and
is often among the most expensive work of the trade. But when
the machine and dies are in successful operation the saving of
labor in production is enormous, and is greater than that saved
by any other machine tool. In fact the most elaborate and costly
articles are often numerously produced by the power press, which
could not be made by other processes for one hundred times or
even one thousand times the cost.
Until lately the power press, by reason of its rapidity of pro-
duction and the manifolding of its product, was distinctly a fac-
tory machine. But to-day this same machine is employed almost
universally in up-to-date machine shops for the production of an
endless variety of parts which are used on machines, and it is to
be reckoned with the same as the other machine tools ; that is, as
an economic producer of shop products.
432
INTERCHANGEABLE MANUFACTURING. 433
PERFORATING FLAT AND CYLINDRICAL SHEET
METAL.
In the production of plates and articles with numerous per-
forations, dies accompanied by novel mechanical devices play a
more important part than any other line of sheet-metal work.
While the dies used in such work are comparatively simple, the
devices and appliances used in connection with them are often
intricate and novel. Especially is this so in the perforation of
cylindrical articles and parts, where the die remains stationary
and the shell is rotated successively at each stroke of the press,
until the entire surface has been worked upon. By means of
these rotating devices shells may be perforated in any design or
pattern of perforations by means of a single row of dies, the
manner in which the shell is rotated after each stroke determin-
ing the pattern of the perforations. Anyone who has noticed
the odd, novel, and artistic designs in the perforated shells used
on gas and lamp burners and fixtures must have wondered how
they can be produced so cheaply. The secret lies principally in
the devices used for rotating, and farther on I show a number of
such devices and the dies and tools used with them.
In the perforating of flat sheets of metal the construction of
the dies used is equally similar to that followed out in the "gang "
types, and they are used on work ranging from ornamental sheet-
metal articles to the punching of holes in steel beams and boiler
plates. The holes pierced with this type may be of any shape
desired and may be spaced in any manner or combinaton. Often
the usual conditions are reversed and instead of the perforations
being desired, small blanks are the objects sought, a number of
them being fed to the dies automatically. Perforated sheets of
the different metals are now in great demand and are used for a
variety of purposes too numerous to mention.
ATTACHMENTS FOR CYLINDRICAL PERFORATING.
In Fig. 504 is shown a horizontal two-slide foot press for
punching simultaneously two holes or slots on opposite sides of
drawn shells. The die is located in the centre and is made with
28
434
TOOL-MAKING AND
cutting-edges on opposite sides and with a clearance hole through
the bottom as an escape for the scrap or punchings. The punches
are of steel rod fastened in punch-holders or chucks which are
adjustable and mounted on slides provided with adjustable gibs.
Each slide is arranged with an adjustable stop to allow of pierc-
ing shells of different diameters. Dies of this type, when used
in a machine of the kind shown, are very convenient for rapidly
and accurately producing pierced shells for lamp-burners, satchel
locks, and a variety of other pierced work recpiiring holes pierced
on opposite sides.
Figs. 505 and 506 show two different sets of perforating fixtures
in position on presses for perforating burner shells and other
Fig. 504.
FIG. 505.
cylindrical sheet-metal articles. Fixtures of these types are used
extensively for work which it is desired to perforate all around,
although sometimes used to perforate in sections only.
The attachment shown on the press in Fig. 505 is used for
taper and crowning shells, which necessitates the setting of the
die-holder and rotating device at an angle with the lower face of
the slide. The shell, as perforated, is shown on press bolster at
the right.
Fig. 506 shows a press equipped with dies and fixtures for
perforating small close patterns in bottomless shells. As will
INTERCHANGEABLE MANUFA CTUBING.
435
be seen from the engraving, in which a die, punch, and two per-
forated shells are shown on the floor, the die is a piece of steel
with two rows of holes in it and dovetailed into the work-holder,
while the punch is equipped with a spring stripper and two rows
of piercing punches. The dies shown located in the press are
Fig. 506.
for perforating the small shell, and the ones on the floor for per-
forating the large one shown at the right at the bottom.
In the attachments of the types shown in Figs. 505 and 506
the perforating dial with a chuck of suitable shape is mounted
on a die-holder, and a ratchet having teeth spaced to suit the
holes or pattern desired is mounted and arranged to rotate the
shell at each stroke of the press. By the use of such attach-
436
TOOL-MAKING AMD
meiits, perforating may be done at the rate of 150 to 200 strokes
per minute.
The adjustment of the parts of these perforating attachments
is easily and quickly made, so that but a short time is required
to change the attachments from one style of shell to another.
Presses in which such attachments are used are often provided
FIG. 507.
with a latch lock for the clutch connection, which is automatic-
ally released after each complete rotation of the article on the
perforating chuck, thus stopping the press automatically after
the requisite number of strokes have been made.
INTERCHANGEABLE MANUFACTURING. 437
PIEBCING AND BLANKING SMALL ABMATUBE
DISKS.
In Fig. 507 is shown a set of dies as located in an adjustable
press for accurately piercing and blanking armature disks for
small generators and motors. The press is furnished with an
automatic knock-out, and its inclined position allows the blank,
Fig. 508.
after being punched and pierced, to be lifted out of the die and
slid off at the back. The pierced blanks are usually punched
from strips sheared to the necessary width. The construction of
the dies is such as to allow the outside and the inside to be
punched simultaneously, after which it is held between the faces
of the blanking punch and the pad, and descends far enough for
the piercing punches located around the die to pierce holes.
The fiuished disks are shown beneath the press.
438 TOOL-MAKING AND
KEEPING SHEETS OE AETICLES STEAIGHT WHILE
PEEFOEATING.
For perforating articles of considerable size, or flat plates
which are required, to be kept straight, dies of the usual con-
struction will not do good work, as on such dies stationary strip-
pers are used and they are liable to distort the metal to such an
extent as to require subsequent straightening. To overcome this
defect a press equipped with a cam -actuated stripper should be
used, especially on accurate work, such as parts of clocks, elec-
trical instruments, etc. A press equipped in this manner is
shown in Fig. 508. The stripping device is such as to leave a
clear space between the punch and die, thus allowing the oper-
ator to manipulate and observe the work at will. The action of
the stripper when the press is running is as follows : The strip-
per plate strikes the blank or article first, straightening and
clamping it before the punches enter, and holding it under
pressure while the punching and stripping are being accom-
plished. In this manner the flat or formed piece comes out per-
fectly straight and true. The punches used when a press is
equipped with a stripper of this type may be made considerably
shorter than where a die with a stationary stripper is used, thus
making them more durable. Also by this arrangement a smaller
hole in proportion to the diameter of the punches may be pierced,
through the support given the punches by the movable stripper
up to the point where they enter the stock.
PEBFOEATING LAEGE SHEETS OF METAL IN"
SPECIAL DESIGNS.
For the perforating of large sheets of metal in designs simi-
lar to those shown in Figs. 509, 510, and 511, special feeding
arrangements are used. Some of the patterns are staggered and
others are regular, and to produce them a single row of "gang"
punches and dies or a double row is used. When a double row
or "gang" of punches and dies is used, the metal is usually fed
automatically by means of a roller feed to a press of large and
powerful construction. The construction of the punches and
INTERCHANGEABLE MANUFA CTUBING.
439
dies for such work is such as to allow of removing any one or a
number without disturbing the others. The punches are usually
located in a cast-iron holder which is fitted to a dovetailed chan-
nel in the face of the press ram. They are short and stocky and
fastened by set-screws. The dies are usually tool-steel bushings,
hardened and ground, and let into holes drilled and reamed in a
bolster of similar make to that used for the punches. The bush-
ings also are fastened by set-screws. With a powerful press
Fig. 509.
Fig. 510.
Fig. 511.
equipped with proper feeds and punches and dies the author has
seen 154 f -inch holes punched in ^-inch plate at each stroke of
the press. The press referred to was used in the works of a
large agricultural machinery concern and was provided with a
roller feeding attachment consisting of four adjustable rolls, 6
inches in diameter and 54 inches long, which fed the stock auto-
matically in multiples of sixteenths of an inch up to four inches.
For heavy work the press was provided with back gears, which
were thrown out when doing light work, so as to give the press
a higher speed. The slide adjustment on this press was such as
to allow of raising or lowering it to overcome the shortening of
the punches through wear.
PEODTTCTION OF PEEFOEATED METAL BY THE
ALLIS-CHALMEES COMPANY.
One of the largest producers of perforated metal in the world
is the Allis- Chalmers Company, of Chicago. In their shops im-
proved machinery is being constantly provided for the produc-
tion of perforated metal in the endless varieties which modern
demands necessitate. The chief aim in this plant is to produce
440
TOOL-MAKING AND
the material at the lowest cost and in the shortest time possible.
This object, of course, can be attained only by keeping the
machines constantly producing perforated sheets of the same de-
sign and pattern. Most of the output in this line produced in
the above-mentioned shops is used for rotating screens for stone,
grain, coal, ore, etc. , the perf orated plates being rolled to exact
diameters in special machines. For such purposes perforated
metals have superseded and are far superior to wire cloth ; being
much stronger, more uniform in size of hole and mesh, less
liable to tear or rust out, and in case of breakage they may be
easily repaired or replaced without affecting the entire sheet. In
screens for various purposes it is often desirable to arrange them
with portions left blank. This can be easily done when perfor-
ated metal is used, as the sheets can be perforated in a press
equipped with a feed which can be adjusted to feed unequal
spacings.
HORNING AND SEAMING PROCESSES.
In the manufacturing of pieced sheet-metal ware, the proc-
esses of "horning" and "seaming" play a very important part,
Fig. 512
and a large variety of ingenious devices and fixtures is used, giv-
ing rapid and accurate results. The processes are essentially
assembling and preparing ones, as they assemble flat, round, and
INTERCHANGEABLE MA MUFA CTURING.
441
irregular parts, and often prepare them for subsequent opera-
tions of wiring, curling, etc. The successive stages of a "lock"
seam are shown in Fig. 512 and a press equipped with the tools
in Fig. 513. The manner in which an inside or an outside seam
is finished is shown, two blows being necessary for each. The
first operation is the forming of
the hooks, and the second the
crushing down and locking to-
gether. There is a large variety
of work which requires finishing
with locked seams of this kind.
For the double -seaming of
bottoms, tops, and parts of
round bodies together, the work
is accomplished by special ma-
chinery and dies are dispensed
with. A machine for this work
is shown in Fig. 514 and dia-
grams of the work done on it
in Figs. 515 and 516. These
machines are used extensively
for double seaming "flat bot-
toms" on to tea-kettles, coffee-
pots, pails, and similar goods in the tin and enamelled iron-
ware line.
The lower spindle carrying the "inside chuck or roller "is
mounted on a sliding plate, which is drawn forward for putting
on and taking off the articles. In the case of flaring pails, dish-
pans, and other articles which are smaller at the bottom than at
the top, the double seaming is done against a solid plate of the
size of the bottom, mounted on the sliding spindle. For buckets,
cups, and other straight articles collapsible chucks are used.
These chucks are so made that they spread to fit along the edge
of the bottom when the article is carried up against the upper
chuck, and fold together after the work is done to permit the
rapid and easy removal of the seamed article.
For double-seaming bottoms or tops stamped or drawn with
a burred edge, as per Fig. 517 and 518, a fixture called a deflect-
FiG. 513.
442
TOOL-MAKING AND
ing device is required and may be readily attached to the ma-
chine. The diagrams show the steps in which the seaming is
done; the deflecting device performs the second of the three
Fig. 514.
INTERCHANGEABLE MANUFA CTUBING.
443
operations. The use of burred-edge blanks for the bottoms of
round work offers the advantage of easily centring the bottoms
on the bodies. For a great many articles, however, plain bot-
tom blanks are preferred. In that case the deflecting device is
dispensed with, and instead of it two brackets are attached to the
Fig. 516.
machine, carrying three adjustable rolls for centring the blanks
or bottoms on the bodies, before clamping. For heavy stock it
becomes necessary sometimes to have a slight depression in the
First Step
Burred Edge Top
f
7
Fig. 517.
Fig. 518.
centre of the bottom blank corresponding with a slight projec-
tion on the clamping plate, so as to prevent the pressure of the
seaming rolls from pushing the bottom away from its central
position.
For a certain kind of work a press specially equipped with
an automatic fixture for double horning or seaming is used. By
means of this automatic fixture the two corner seams on large
square cans having round corners with seams in the centre, may
be closed at one blow. Tins with sharp corners require a " coax-
ing " operation on a single horn to start the seam over before
setting over on a double-horn press. The horn, which is movable
444
TOOL-MAKING AND
in ways, has two working surfaces, the upper one being acted
upou by a " force " bolted to the press slide, while the lower one
in descending with the slide acts against a stationary force fast-
ened to the bed. It will be understood that the two body-halves
of the can, loosely hooked together, are pushed over the sliding
horn, as shown in Fig. 519, which, by means of adjustable
gauges, secures accurate size and position. By the use of a
FIG. 519.
Fig. 520.
double -horn machine the capacity of the operator is nearly
doubled as compared with what can be done on an ordinary
horn press. Presses equipped with fixtures for double seaming
are used extensively for seaming 5 -gallon petroleum cans, as
per Fig. 520.
Double-seaming machines (Fig. 521) for seaming articles of
irregular shape differ from those of the type shown in Fig. 514
in that they allow the seaming rolls to follow automatically the
INTERCHANGEABLE MANUFACTURING. 445
shape of the can. As they do the seaming at the top of the can,
they are preferable for filled cans. In action, the pressure on
Fig. 521.
the foot treadle, which causes the pressure plate to clamp the
can and lid against the chuck, also throws in the friction clutch
which starts the work. The double-seaming rolls, controlled by
446 ' TOOL-MAKING AND
a cam made in a piece with the chuck and finished to the shape
of the can, follow the shape of the can automatically, while the
necessary pressure to form and finish the seam is imparted by
the haudles. These pressure handles in such machines are so
arranged as to relieve the hand of the operator from all vibra-
tions due to the irregular shape of the cans. Adjustments for
different heights of work can be readily made by means of a
hand-wheel, and for different shapes by exchanging the can
chuck, which can be done in a few minutes.
The rolling of seams on square cans is usually accomplished
in the following manner : The can is firmly held between two
disks made exactly to fit the heads of the can; the upper disk
being mounted on a vertical shaft fastened rigidly to the upper
part of the main frame of the machine and the lower disk to a
shaft passing through the lower part of the frame and prevented
from turning by an arm running in the guides, but capable of
vertical motion imparted to it by a cam on the treadle shaft.
The steel rolls which operate on the seam at the top and bot-
tom are carried by a frame which rotates upon the upper and
lower stationary shafts and revolves around the can. These rolls
are mounted on levers pivoted in the rotating frame, the oppo-
site ends of the levers being finished with rolls bearing against
star-shaped stationary cams in two vertical shafts which gives
the "in-and-out motion" required in passing around the corners
of the cans. The rotating frame carries two sets of these rollers,
which press upon opposite sides of the can at both top and bot-
tom, thus equalizing the side pressure and rolling the seams more
perfectly than would be possible by the use of the single set of
rolls, each seam being rolled twice in each revolution. There
are additional cams provided which, as the machine comes to a
rest, move the rolls outward from the surface of the cam, so that
the latter may be removed from the machine. Attached to the
bottom of the rotating frame is a bevel gear meshing with a pin-
ion on the pulley-shaft. The pulley is provided with a friction
clutch controlled by the treadle.
A cam being placed upon the lower disk, the foot treadle is
pressed and the can is raised and clamped firmly between the"
upper and lower disks. The clutch is then thrown in, and the
INTERCHANGEABLE MANUFACTURING. 447
roller frame makes one revolution around the can, the latter
remaining stationary. After completing the one revolution the
clutch is automatically released, the rolls are thrown outward
and the lower disk drops, leaving the can free to be removed.
The capacity of these machines is from 9,000 to 12,000 cans in
ten hours, and the saving of solder alone by the use of each ma-
chine amounts to from $15 to $18 per day.
For double-seaming the bottoms on large heavy work, such
as foot-tubs, bath-tubs, wash-boilers, cauldrons, and other large,
oval, oblong, or square articles, when the bottoms are required
to be fastened without the usual recess next to the double seam,
a large machine of special design is used.
In this machine a high chuck is used, fitting the inside of the
article, and the double-seaming is done against the inside of this
chuck. In order to establish the correct position of the bottom
blank in relation to the body, the blank is usually stamped with
a slight depression at some distance from the edge, which fits a
corresponding depression in the top of the chuck. To facilitate
the taking off of high articles, there is usually an upper arm on
the machine which carries the clamping-plate that is arranged
to swing out of the way.
For the double-seaming of tops, bottoms, or parts of special
shaped articles, special chucks and devices are necessary ; how-
ever, the principles involved are all very much the same in all
work of this class, and a knowledge of the methods in general
use will enable anyone to accomplish the desired results without
trouble.
CUELING AOT) WIEING PEOCESSES.
I will here take up a class of press tools and fixtures to ac-
complish results in sheet metal which a few years back were pos-
sible to attain only by spinning. The operations in which these
tools are used are curling and wiring oj)eratlons, respectively.
Curling is producing a curled edge around the top of any formed
or drawn articles of sheet metal. Wiring is the curling of the
top of such an article around a wire hoop when it requires stiff-
ening. The tools used for either curling or wiring are of almost
the same construction.
448
TOOL-MAKING AND
J
Curl Started
^A , I "~Al
Half Curled
In straight work and work but slightly flared simple dies can
be used to turn the metal, when wiring, around the wire and
under it, perfectly at one stroke of the press. From 2,000 to
8, 000 pieces can be wired per day of ten hours.
Figs. 523, 527, 530, and 531 show cross-sections of dies which
may be used for curling the edges of circular drawn shells. Of
course, it is impossible to see the action of the metal in work of
this kind while the die is working, but by noting the condition
of the shells at intervals daring the
curling, by working the die down and
up by hand, the process can be seen
and understood. The groove in the
upper die (or lower die, as the case
may require) must be finished at the
back to a perfect half- circle of the
radius required, and must be lapped
and polished until free from all cuts
and scratches, in order to get a clean,
smooth curl. The sketches in Fig.
522 show how the upper die curls the
edge of a half-round shell. In the
first stage A the metal has commenced
to curl ; at the next stage B the metal
has curled to a half- circle of the width
of the curling groove in the upper
die. At C the third stage .is shown ;
the j)unch continuing downward; as
the edge of the shell passes the centre
of the curling groove the pressure is
exerted on the top of the half-round
curled edge and causes the metal to curl further around until
the circle is complete, as shown at D. In this manner only one
operation is necessary to curl the edge of a shell of the type
shown, as the metal once started around the curling groove of
the upper die will follow the curl on the same radius as long
as the pressure continues, or until the edge strikes the side of
the shell, when it will curl within the first curl. Thus a
shell may be quarter curled, half curled or completely curled
Fig. 522.
INTERCHANGEABLE MANUFACTURING.
449
by the same die, according to the length of stroke to which the
die is set.
When the edge of a shell of the shape shown at Fig. 524 is
desired to be curled as shown at 526 the work will require two
Fig. 523.
dies. The first die is to bend or form the edges to the upright
position and the second die to curl the edge. This second die is
Fig. 524.
shown in Fig. 527. The upper die is made so as to make the
entering of the edge of the shell positive within the curling
Fig. 526.
groove, and also so that the straight inner wall will hold the wall
of the shell while the edge is curling, thus preventing any bulg-
29
450
TOOL-MAKING AND
iug during the process, which would occur if the inside of the
tool was finished like the outside. In this manner the metal is
held tightly, and as the ram descends it must follow the shape of
the curling groove.
The curling of the edges of drawn shells by means of dies of
the above type is done in endless variety ; the articles worked
Fig. 527.
upon ranging from shoe eyelets to bath-tubs, of both round and
irregular shapes. The design and construction of the tools de-
pends en the shape, the thickness of metal, and the diameter of
* TfJT 1M8
FIG. 528.
curl required ; however, the principles of construction involved
are the same in all of them.
The tools in Fig. 530 show how shells of different shape may
be curled. For the operation shown at A and B a combination
die and a bending die, respectively, are used. The curling as
shown at C is done in the die shown.
INTERCHANGEABLE MANUFA CTUBING.
451
The manner in which curling dies are used for "wiring" on
both large and small work will be understood from Figs. 531
and 532.
Dies of this type may be used for "wiring" or simple "curl-
ing" on round or oval shells, as long as they are straight or
Fig. 529 a.
Fig. 529 b.
nearly straight walled, and are properly supported during the
process. A tool-steel ring A is attached to the punch-holder.
The inner diameter of this ring must fit accurately the inside of
<_ _
Fig. 530.
the shell to be wired, so as to prevent bulging or crimping of the
walls. When "wiring," the ring B is used in the lower die.
When the dies are in use a wire hoop, which fits the outer
diameter of the shell, is placed in position on the ring B and
around the shell which is located within the dies as shown. The
452
TOOL-MAKING AND
ram then descends and the edge of the shell is curled around
the hoop, enclosiug it within it, as shown at the bottom of
the cut.
A curling punch and die for curling deep shells or articles
of thin sheet metal, and a section of the press in which it was
Fig. 531.
used, are shown in Fig. 533. The punch is located and fastened
within the ram, while the die is on a sliding table which may be
pulled back and forth by the operator. The horn or die for
FIG. 533.
locating the work is of slight taper, and consequently a solid one-
piece curling punch can be used, as the decrease iu diameter
when curling is so slight that contraction of the curling ring is
unnecessary. When in use, the table on which the horn or die
INTER CHANGEABLE MANTJFA CT UBING.
153
is located is pulled out to allow the article to be slipped over it.
This is doue, aud the table is moved back to place against the
stop shown. The punch then descends and the edge of the
article is curled. The punch ascends, the table is pulled out, the
Fig. 533.
work is removed, another piece is located, and the operation is
repeated. When a press with an automatic die slide is used the
curling or wiring is done more rapidly.
MANUFACTURING AEMATUEE DISKS AND
SEGMENTS.
The adoption and use of dies, power-j^resses, and special sheet-
metal working machinery for the economic production of parts
of electrical apparatus has had great development during the
past few years ; so that to-day establishments that manufacture
sheet-metal working machinery dispose of a great portion of
their product to electrical machinery manufacturing concerns.
One has only to examine an electrical device or a machine to
realize what a factor the power-press has become in their pro-
duction. The parts of electrical apparatus for the production
of which such machinery is used most extensively, are armature
disks and segments for motors. It is at once obvious that the
requirements for such work have led to the designing of dies,
presses, and special machinery which differ in essential details
from those used in the general and more familiar classes of sheet-
metal working.
454
TOOL-MAKING AND
An armature consists of a wired " core" composed of thin
sheet-iron plates or disks averaging from .010 to .040 thick and
10 to 100 inches in diameter. In many of the best armatures the
disks are produced by punching the centre hole, key slots and
notches, or winding slots, simultaneously at one stroke of the
press. The small sizes are thus produced in dies, while the
larger ones are produced in sections or segments of as large
size as it is possible to procure iron for. In the cheap and
inferior armatures the disks are first punched from plain sheets ;
the punching of the centre holes and the key slots is a second
FIG. 534.
operation, after which the disks are assembled on shafts, the
outside turned to the required diameter, and the slots milled on
a universal milling- machine.
Machines and dies used for cutting and perforating armature
disks and segments differ according to the size and shape and
number or quantity required. There are in general use four
methods for cutting armature disks. On the size and quantity
of disks desired depends the practical value of each.
Disks of very large diameters, or those required in relatively
small lots, are usually first cut plain by shearing the outside cir-
cle and afterward the inner circles on circular shearing machines
of the type shown in Fig. 534. As shown, the lower cutter is in
an angular position relatively to the upper, so as to permit the
INTERCHANGEABLE MANUFACTURING. 455
making of as clean a cut ou the inside as on the outside. Disks
cut in this manner are afterward notched on an automatic notch-
ing machine of the type shown in Fig. 535. A plain blanking
or notching punch and die are located in the press portion at the
left and a circular disk clamped between the two pads of the
indexing and revolving the mechanism at the right. The index-
ing is entirely automatic, the spacing and number of notches in
a disk depending on the arrangement of the gearing.
In this machine the adjustment for different diameters is
made by simply turning the hand-wheel shown. The adjust-
Fig. 535.
ment for different numbers of notches is effected by means of
the change gears shown, instead of a pawl and index-plate device
as is usually employed. Each set of gears can be arranged to
answer for three different numbers of notches. The index feed
is effected by means of a "Geneve "stop movement; but abso-
lute correct indexing is assured by the use of a positive cam-
actuated locking device for the indexing arbor.
456
TOOL-MAKING AND
In connection with the punch and die used in a machine of
this type a spring stripper is used, so as to leave a clear space
above the die ; making it easier to introduce a new disk, and at
the same time provide for holding the disk under pressure when
the notch is being punched. This, consequently, obviates the
necessity of using a clamping plate over the centre of the disk.
FIG. 537.
When disks of the polyphase motor type, having holes or
notches punched in the inner periphery, are required to be
notched in a machine of this type, it is necessary to do the
notching before the large inner circle is removed, as its surface
is needed for carrying the disks in notching. In such disks one
or two small holes are previously punched in that portion of
them that is afterward cut away, in order to serve as guides in
the notching and centre-hole punching operations.
The kind of disks which are of moderate diameter and most
frequently required in large quantities are those used for street-
FiCx. 538.
FIG. 539.
Fig. 540.
car motors. To produce them powerful power-presses are used.
These presses are equij)ped with dies so constructed and arranged
that the inside of the disk with its key-slot, and the outside with
its notches, are cut simultaneously at one stroke, as shown in
INTERCHANGEABLE MANXJFA GTUBING.
457
Fig. 540. This method constitutes the quickest, most accurate,
and economical way of manufacturing armature disks in large
quantities. The presses in which such dies as are necessary for
such work are used, are provided with knock-out attachments
which discharge the scrap and the disks so that they lie loosely
on top of the dies, thus allowing of their easy removal.
In regard to the power-presses used for disk punching, it may
be stated that the requirements of armatures for electric work
FIG. 541.
Fig. 542.
have led to the construction of presses which differ in points
from those used for other styles of sheet-metal working. As it
is always essential to have the outside and inside exactly concen-
tric, so that all notches in the disks shall coincide perfectly with
Fig. 543.
one another when assembled in " cores, " it has been found best to
adopt dies which, by being cut simultaneously, eliminate the
inaccuracies which are wellnigh unavoidable when the cutting
is done in two or more operations. In many cases, the notches
and key-seats are also punched at the same time. To accom-
plish these results in one operation, dies of great accuracy are
458
TOOL-MAKING AND
required, which, in addition to the cutting parts, must be
equipped with "knock-out" pads that will automatically deliver
the punched disks and scrap from within the dies. The dies
used in these methods of producing the disks are known as
"compound dies," and are usually built up in sections which
have been hardened, ground, and lapped to size. However, not
infrequently, they are made in the usual manner, but the results
are not so accurate. These compound dies are very expensive,
costing all the way from $150 to $1,000 each. Fig. 543 shows
plans of a compound punch and die. As a rule these compound
dies are used in presses provided with upper and lower die
knock-outs, thus obviating the necessity of the strippers in the
dies. . The die sections are located in a steel casting. The rings
are of tool steel, carefully and accurately worked out, hardened
and ground to size, while the remaining ones are left soft. The
dark sections in the figure indicate the cutting parts.
As the installation of the above-described method entails a
great deal of expense and can be adopted economically only
where disks are required in large, steady quantities, it is at once
apparent that the dies would be too costly to use for producing
Fig. 544.
disks in small lots. For this reason another method is in vogue.
This method consists of cutting out simultaneously the plain out-
side and the hole, as shown in Fig. 536, and then punching the
notches on a notching press. By this method a perfectly con-
centric blank is produced ready to be notched. As by this
method the outside notches are cut separately, the power of the
INTERCHANGEABLE MANTJFA GT UBING.
459
presses in which the work is done is equal to much larger- diame-
ters than those used in the method before described.
In producing very large disks there is a great deal of scrap,
but this scrap is prevented from going to waste altogether by
being worked over into disks of smaller size. From the inside
scrap, the projections corresponding to the key notches are re-
moved by forcing the disk through a circular trimming die which
punches the centre hole at the same time, and thus no great
waste of stock is entailed.
In manufacturing armature segments in very large quantities
the outside and the holes are usually cut simultaneously in dies
in which the stripping of the scrap and the segments from them
is entirely automatic, for both the upper and lower sections. A
press specially designed and used for this class of work is shown,
Fig. 546.
equipped with proper tools, in Fig. 547. The cutting of sec-
tions and segments complete with dovetails, and all notches and
holes up to 35f inches long, can be done on a press of this sort.
However, most segments of large size are first punched plain and
the notching and perforating are done in succeeding operations.
460
TOOL-MAKING.
When the plain segment blanks are not produced in dies, a
circular shear of the same type as that used for disk cutting is
used ; it being equipped with a segment-cutting attachment, as
shown in Fig. 545.
In Fig. 546 we have a side view of an armature-segment
notching press. The segment-notchiug attachment on this ma-
chine allows of handling segments having a radius of from 36 to
96 iuches and up to 36 inches in length. The manner in which
Fig. 547.
the segments are notched is as follows: The segment to be
notched is clamped in a holder at the forward end of a long
radius bar, and is traversed across the die face by means of an
indexing mechanism and change gears similar to those on the
regular disk notching press ; when the segment is notched all
around the outside or inner edge as required, the press stops
automatically. After the operator releases a hand lever the seg-
ment may be returned to its original position and removed from
the press.
CHAPTER XXVIII.
The Manufacture of Accurate Sheet-Metal Parts in
the Sub-Press.
THE SUB-PEESS.
The great increase in the manufacture of innumerable small
machines of precision which are made up almost entirely of sheet -
metal parts, together with the increasing demand for cheap but
FIG. 548.
accurate watches, clocks, time recorders, meters, cyclometers,
and other articles, the utility of which depends entirely upon
their precision, has created a demand for accurate presses, dies,
461
462 TOOL-MAKING AND
feeding devices, and automatic arrangements with which to pro-
duce sheet-metal parts in endless repetition with their complete
interchangeability assured. For the production of such parts,
dies of great accuracy, together with feeding devices which are
positive in action, and the sub-press are necessary.
Sub-presses are distinctly different from the other machines
which are used for the usual or ordinary lines of sheet-metal
work, in that they are made so as to form component parts of
the dies, and that they are used almost exclusively for the deli-
cate dies which are required in the economic manufacture of
parts of the kind used in the machines, devices, etc., enumerated
above.
UTILITY OF THE SUB-PEESS NOT GENEBALLY
UNDEBSTOOD.
Notwithstanding the extensive use to which the sub-press and
its accurately made dies have been put, its use and the making
of the dies for it are not understood by superintendents, fore-
men, and tool-makers of sheet-metal goods establishments as they
should be. Thus the more extensive use of these tools has been
interdicted. Were the case otherwise, and the utility of the sub-
press and the making of its dies more generally understood, there
would be less worry and more satisfaction in the accomplishment
of results which, in many establishments, are at present being
attained by means which are now obsolete. In view of this state
of affairs I feel that complete descriptions of the sub-press, and
how to use it and its dies, will be of great value to all engaged
in the manufacture of accurate sheet-metal parts, articles, or
devices.
PEINGTPAL USE OF THE SUB-PEESS.
The principal use to which the sub-press is put, is for the
manufacture of sheet-metal parts which, because of their unusual
accuracy, have to be produced in dies which cut the outside and
the inside, as well as any perforations, simultaneously, or at least
within the one compound die. By the use of the sub-press and
its accurate dies the finest work may be accomplished with ease,
INTERCHANGEABLE MANUFACTURING. 463
as the dies may always be kept finely adjusted for the work;
while the enlinement will be perfect, and thus the possibility of
shearing will be entirely eliminated.
COST VS. LONGEVITY OF THE STIB-PBESS.
In regard to the cost of a sub-press and a pair of dies for pro-
ducing an intricate sheet-metal part, the first outlay is consider-
able ; but then this is really all the cost, as the construction of
the press is such that no damage can be done to it while it is
being set up or run in the power-press ; while the dies for it
require but little repairs outside of an occasional grinding of the
faces. When it is stated that from 50,000 to 100,000 perfectly
interchangeable blanks may be cut and pierced in a sub-press
without grinding the punch and die faces, the accuracy and long-
evity of the tools may be imagined.
HOW TO CONSTBTTCT A SUB-PBESS.
In order to be able to construct a sub -press or a set of dies
for it the tool-maker must be both skilled and accurate, and must
use great judgment ; possessing these qualities he may, by care-
fully digesting the following described methods, be sure of suc-
cess.
Fig. 548 shows in vertical section and Fig. 549 in plan, a
sub -press such as is used in all watch, meter, and cyclometer
factories. The sub-press consists of the stand 1, the plunger 2,
the base 3, the nut 4, to tighten the babbit lining, and the hook
nut 5, which connects the j>ower-press plunger with the plunger
2 of the sub-press. The stand 1 is the first part machined. It
is faced and bored on the bottom, and then the barrel is faced
and recessed to suit a flange by means of which the plunger 2 is
centred at one end for babbitting. The stand is then ready to
be drilled and tapped for the fillister head-screws, by means of
which it is fastened to the base. These screws are also used
to fasten the stand to a special lathe-chuck, by means of which
it is bored 3 degrees, taper-faced on the other end, and then
turned for the adjusting nut, but not threaded until the stand
has been babbitted. The stand having been bored it is then set
464
TOOL-MAKING AND
up in the shaper or keysetter, and four grooves are planed in the
inside, parallel with the taper, to prevent the babbitt lining from
turning.
We now rough-turn the plunger 2, back-rest it, and then bore
it for the punch piston ; after which it can be threaded for the
nut 5. This nut should be made
of machinery steel, and have two
flats milled on it at o o, so as to
be able to remove it from the
plunger. With this nut well
screwed down the plunger should
be turned to within about .005
inch of the finish size, and then
finished by grinding, making sure
to have it perfectly parallel;
after which it should be placed in
the miller vice, and four grooves
milled in it, being sure to have
the miller vice exactly in line ; if
the vice is slightly "out" a twist-
ing motion will occur in the
plunger when in operation in the
press, and this will, of course,
spoil the dies. ]STow we draw-file
the plunger, using No. 2 emery
stick, which will give better re-
sults than a file, and then all is
ready for the babbitting. We
get the babbit at the right heat,
pour it, and allow it to rise
about £ inch above the top of the
stand.
As soon as the stand has cooled enough to handle, the plun-
ger should be forced down far enough to allow the babbitt to be
faced and squared off on the end, and the thread cut on the end
of the stand or nut 4. ISTow remove the plunger from the stand,
and locate the stand in the lathe again; then cut a spiral oil
groove of about 1-inch pitch in the babbitt lining. The stand
Fig. 549.
INTERCHANGEABLE MANUFA CTUBING.
465
and plunger should now be secured in the power-press, and
pumped, using plenty of oil, and tightening down the nut occa-
sionally so as to get a good bearing. It must be watched at this
stage, in order that excessive friction may -not heat the babbitt
lining sufficient to cause it to swell, and thus destroy the stand.
Now reface the stand in the lathe, and face the bottom and bore
the seat about 2 degrees taper to fit over the taper boss on the
Fig. 550.
base. The plunger may now be removed from the stand, back-
rested, and recessed for the dies. The base can then be located
on the face-plate of a lathe — having previously planed the bot-
tom — and the boss turned 3 degrees taper to suit the stand ; also
recess it for the dies and lower stripper, after which it can be
drilled and counter-bored, and then doweled to secure the per-
fect alignment of the two sections.
SETTING AND WORKING A SUB-PRESS.
The sub-press can be worked in almost any power-press of
suitable space. However, usually, a special press is used for the
purpose, as a short stroke and a stiff arch -framed press best meet
the requirements ; Fig. 549 shows a press of this kind.
To set a sub -press, simply slip it into place, as shown in Fig.
549, by sliding the steel neck of the plunger into the press-slide
hook, and theu locate the hold -drawn clamps into their places
and tighten the screws or nuts, thus fastening the sub -press
firmly to the bed of the power-press or bolster plate. The dies
30
466 TOOL-MAKING AND
may now be set and all is ready to proceed with the punching.
The changing of a sub-press is very quickly done, as no special
skill is required. There are several different styles of sub-press
frames ; the most common is the round barred-arch shape. An
overhang pattern is often used. For the very largest work,
such as clock or time-register frame backs, a four-pillar sab-
press, which cuts quite large blanks from stock as thick as
T 3 -g inch, is used. The manner in which the punching in a sub-
press is done must not be confounded with ordinary punching,
as it is done in a different manner. As a rule three or more
operations are performed at one stroke of the press — that is, cut-
ting the outside, cutting the centre, perforating the blank, and
lettering it all at once. The stock to be punched is securely
held between the stripper plates and pads ; thus the die is com-
pound; thus the metal is straightened and held* perfectly flat
while being worked upon, and each and every piece produced is
an exact counterpart of the one previously cut.
ACTION OF THE DIES— FEEDING OF THE METAL.
In the production of the most accurate classes of work in the
sub-press, the punch does not enter the die proper, but descends
within a shade of its face, thus parting the blank from the stock,
and no more ; the strippers flatten its edges out square. It must
be understood, though, that the die and punch faces must be
perfectly flat and without any shear in order for the work to be
produced accurately ; for this reason a stiff, well-made press is
required. Because of constructing the dies in this manner their
longevity is greatly extended, as the punches merely pass through
the comparatively soft stock and not in and out of the hardened
dies, which would shear and wear them quite rapidly. Never,
under any circumstances, allow the punches to enter the dies, as
this will spoil the tools in a short time.
As the sub-press is a small, convenient machine in itself,
with its dies and punches always in perfect alignment, with no
possibility of fitting out of order, it is always set ready for work
aud all chances of bad or inaccurate work are eliminated. While
the first cost of this little machine is large, in the long run it is
INTERCHANGEABLE MANUFACTURING. 467
the cheapest die that can be devised for the accurate and rapid
production of perfectly interchangeable sheet-metal parts. It is
this little tool that has made possible the manufacture of the
"dollar watch."
Eoll feeds, or other automatic feeding appliances, are often
added to the presses in which these sub-press tools are used. As
the articles cut are forced back into their place in the stock from
which they were punched by the strippers in the dies, the meta-
stock is kept straight and it is punched and accurately fed along
under the dies at a very high speed, from 75 to 130 punchings
per minute being produced.
CHAPTER XXIX.
Engraving, Sinking, Constructing, and Using Dies
for Medals, Jewelry, Coins, and Art Goods.
WORKMAN VS. ARTIST.
The cutting and engraving of steel dies for the embossing of
medals, jewelry, and fine sheet-metal work is an art by itself — an
art which, besides requiring mechanical skill and a knowledge
of the use of metal-working tools, requires a natural talent for
that kind of work and the possession of that artistic ability that
comes from the love of things beautiful. Without that ability
the die-sinker is merely a workman, and will be incapable of
originality : it is the talent that makes the artist. However, to
those who are already skilled in the art of die-making and who
possess to a certain extent the ability to duplicate designs, this
chapter will prove greatly instructive ; while to those less gen-
erously endowed the information contained herein will help them
to progress further.
ENGRAVING A HOB FOR SINKING A MEDAL DIE.
In making the dies for medals, etc., the most approved prac-
tice is as follows : Taking a blank ready to be cut, Fig. 551, we
grind the face dead smooth and then either copper it with a solu-
tion of sulphate of copper or give it a thin coat of zinc white
and allow it to dry. We sketch the medallion portion on this
surface, as in Fig. 552, and cut away to the necessary depth all
the outer sections until a perfect silhouette of the figure is ex-
posed, as in Fig. 553. After this the coarser details are cut in,
using small chisels, riffles, and gravers, and boldly rounding all
portions which are to appear thus, as shown in Fig. 554. The
last and most particular part of the work is to eugrave and chase
in the fine artistic details until the work appears finished, as in
468
INTERCHANGEABLE MANUFACTURING. 469
Fig. 555. The "hob" for sinking the die for the face of the
medal is thus made.
MAKING DIES FOR EMBOSSING JEWELRY.
In the making of dies for the embossing of jewelry the usual
practice consists of working out the sample first to the shape re-
quired, after which it should be soldered to the end of the piece
of steel which is to form the punch. These pieces of steel are
usually kept on hand and are turned to 1£ inches diameter and
Fig. 551.
Fig. 552.
Fig. 553.
Fig. 554.
Fig. 555.
are about 5 inches long, with the small end bevelled to a size just
large enough to cover the sample. After the sample has been
soldered to the end of the punch blank the outline of the templet
is carefully and accurately worked out on the end of the punch
by the best means available ; the bench miller will prove the best
means to adopt for doing this part of the work. Carry out the
outline to a distance of about -g 3 ¥ inch from the face of the
punch ; then take the punch to the shaper and carry the shape up
the length of the punch ; tapering it to run out about 1^ inches
from the face. After this carefully file and finish all points
round, so that the end of the punch will have the perfect outline
of the sample. The sample may now be removed and the face
of the punch shaped as the finished article is to appear.
This shaping requires a little exercise of the artist's talent,
but it is not very difficult if gone at with a little thought and
system. The systematic method would be to coat the end of the
punch with copperas solution, and scribe a line completely
470 TOOT^MAKING AND
around the punch a distance from the end face equal to the thick-
ness of the finished article.
The dies are usually made' of round annealed stock, turned
to 1-J inches diameter, the ends faced to about -g- inch thick, and
the face into which the impression is to be struck finished to
a very high polish. ]STot the slightest scratch is permissible
upon the face of either punch or die. This being done, take the
punch — which we will now call "master" punch — and the die
blank, to either a screw-press or drop-press, set both in their
respective places, and when all is in readiness, carefully clean
both and oil very slightly with oily fingers. All being firmly
fixed in position, the impression is now made. If a screw-press
is used a few strong blows will be necessary, and if a drop -press
estimate about the proper height from which to drop the weight
with the surface to annealed piece, which will soon teach one
about how much is necessary to strike a given depth. Raise the
weight and let fall, catching the weight before a second blow can
be struck. The result of this will be a clean-cut impression, with
the original polish of surface almost perfectly preserved but car-
ried down into the blank. Of course the metal will be thrown
up around the impression, and this can be faced off in either a
lathe or a shaper, since it is necessary to strike a little deeper
than required because of the edges being rounded. The die is
now marked, etc. , and hardened, using something to insure its
coming out of this process clean, and then the impression is pol-
ished out. It is very necessary for work of this kind that the
dies, etc., be highly polished, and especially so when working
gold-filled stock, for the smoother the work comes from these
dies, the less buffing will be necessary to bring it to a finish.
For the high finish, either Vienna lime or fulminate of iron
will give excellent results. Chuck a round stick — orange wood
— in a speed-lathe or drill-press. Shape the end with a file
while running, and use either of these preiDarations with water.
The Vienna lime is cleaner, fulminate of iron gives the most sat-
isfactory results. We now have a die ready for business, and
when this becomes worn large from use, which it surely will do
in time, another die can be struck from our master punch.
After a punch has been found to give the results sought for,
INTERCHANGEABLE MAN UFA C TUBING. 471
it is a very good plan to strike off several dies at one time,
especially if manufacturing anything like this in large quanti-
ties, as there is a gritty surface to annealed pieces which will
soon wear ont a die, and the form of the piece being changed,
will, in a greater or lesser degree, affect subsequent operations.
It is a good plan also to strike off one die deeper than is in regu-
lar use, finish, and reserve as a master die. This would then
make it possible to reproduce the punch also if by accident or
otherwise it became damaged or lost.
To produce a punch from the master die we must, of course,
use an annealed blank turned up as before and shaped to the
impression in the die. This can well be done by laying out the
outlines on the end of the punch blank, shape it accordingly in
the bench miller, and file it to about the desired shape. Place
the master die and punch blank into the die, though not hard.
Now remove the punch and ease off all spots showing contact.
Eeplace punch blank and repeat until nearly the exact form has
been taken, then ease off the sides slightly, polish highly, and
return to the press for a finishing blow. The object of this is to
work the punch nearly to shape, and to fit the die so that in the
finishing blow the first contact will be in the bottom of the im-
pression. The metal seems to flow into the die better where con-
tact is at first, and should there be a scratch or other sharp
indentation, it cannot be rounded out. It is also interesting to
note that if a drop of oil gets pocketed in the bottom, this oil
will prevent the die being filled out, no matter what pressure is
exerted, so that the rule seems to be for either the punch or the
die: "Let there be no scratches or dents in either surface; polish
highly ; keep the surfaces clean from grit, etc. , and oiled but
slightly with slightly oiled fingers, and rubbed on at that."
Finish the taper part of the punch in the shaper and vice, as
already explained. Polish, harden, and finish as usual.
Quite contrary to what might be expected by many, sinking
small dies in this manner does not induce strains sufficient to be
of any serious consequence, and I dare say that with annealed
steel there is no more chance of loss than by the method of first
heating before striking the impression. In fact, an experienced
man almost never loses a die.
472 TOOL-MAKING AND
When not in use the master punch and master die should be
coated with vaseline and stored away in a vault or other safe
place. If preferred, these tools can be packed in powdered lime,
same as polished spring wire is packed, to preserve the polish.
CHASING THIMBLE, CANE, WHIP, AND TJMBEELLA
MOUNTINGS.
The small indentations on the end of a thimble, cane, whip,
and umbrella mountings, are embossed with knuel wheels where
the design will permit. Very fine work is hand-chased, which
is performed by filling the articles with lead and afterward driv-
ing the thin metal into the lead with chasing tools, the latter
being a small, blunt chisel of proper shape to fit the designs or
ornaments wanted.
MODELING INTRICATE DIE PATTERNS.
The modeling of intricate die patterns is accomplished in
different ways, according to the nature of the work : carving in
wood, moulding in plaster, moulding from "modeller's wax,"
or moulding in gelatin. The once most common method, but
now wellnigh obsolete, was that of carving in wood. For large,
bold designs the plaster cast is the best. First a rough outline
of the work is formed from freshly mixed plaster. After this
has set it is cut or carved into the desired form by keeping it
moist and using sharp wooden or brass tools ; steel tools will not
do, as they rust rapidly. In some cases modellers make their
first model of clay, then make a plaster or gelatin mould from
this by casting ; and lastly a reproduction of the original model
from this cast.
GELATIN MOULDS.
When a clay model has been made and it is designed to repro-
duce in gelatin, soak the best white glue in cold water for
twenty -four hours, drain off all the water, and melt the soaked
glue in a water- jacketed kettle, bringing it to the thickness which
will give it the consistency of soft-rubber when cold. To pre-
vent the gelatin from sticking, moisten the model with a mixt-
INTERCHANGEABLE MANUFACTURING. 473
ure of common soap and lard oil. Pour the glue upon the
model, the latter being incased in a lead or board box ; allow the
mould to cool for about twelve hours, and then separate the cast
from the model by gently rapping around the edges of it. If
the model has two surfaces from which casts are to be made, a
thread should be attached to the back and extended out of the
mould at both ends, so that it may be used for cutting open the
mould and removing the model after the mould has cooled.
Another good recipe for a gelatin mould is the following :
Dissolve 20 parts of fine gelatin in 100 parts of hot water, and
add one-half part of tannin and the same amount of rock candy.
A mould made of glue or gelatin only will become more durable
if a solution of bichromate of potash and water is poured over it
and the mould afterward exposed to the sun. Use one part of
bichromate to ten parts of water. Always remember to oil all
models before covering them with glue or gelatin, otherwise you
will fail to secure a good mould and may warp the model.
- USE OF "MODELLEB'S WAX."
To make impressions of dies in which the designs are very
elaborate, or composed of very fine lines and curves, use "mod-
eller's wax." To make this wax, take two parts of beeswax to
one part of bayberry wax ; dissolve and mix well and then spread
it over the face of the die while warm, first moistening the face
of the die with strong soap water to prevent sticking. To secure
an impression of a large, bold design, use "dentist's plaster,"
mixing it with water until about as thick as molasses. It will
be necessary to work fast, as the plaster will set quickly. Wipe
the face of the die with lard oil and common soap solution and
then spread the plaster over the die, running it from end to end.
After the plaster has set, heat the die slightly and lay it aside
for about twenty minutes, after which rap the edges of the die
until the impression separates from it. In pouring the plaster,
allowing it to flow from side to side will prevent the formation
of air bubbles in the depressions. The further exclusion of air
may be ensured by paddling or churning the plaster. As plaster
shrinks considerably in drying, it will be necessary to remove the
cast from the model as soon as it becomes dry.
474
TOOL-MAKING AND
As a rule, no matter how carefully plaster casting is done,
some defects will appear in the casts, which will have to be
patched. Wait until they are thoroughly dry and cold and then
scrape the damaged surfaces before patching.
DIES FOR FORMING LARGE ORNAMENTAL
ARTICLES.
The dies used for bending and forming large ornamental arti-
cles of sheet metal are usually cast iron. Very little work is
done on such dies, as they are cast from a carefully prepared
model, a facsimile of the article to be formed, using it as a pat-
tern and working out the die surfaces in a manner similar to the
moulding of a pattern in sand. Drop dies are often made in
this way, and from these steel dies are dropped, producing them
to almost the correct finished shape, thus dispensing with con-
siderable difficult filing, chipping, and graving.
WATER, OR FLUID DIES.
All kinds of hollow ware, such as lamp bodies, artistic toilet
cases, match safes such as shown in Fig. 556, silver and Britan-
nia ware and ornamental soft brass shapes, are produced in
Fig. 556.
almost exact reproductions of chased work by means of the
"water die," of the type shown in Fig. 557. The "die" con-
sists of a hinged mould having the desired decorations cut on the
inside. These moulds are usually cast from carefully carved
models and are then finished and touched up until all fine details
INTERCHANGEABLE MANUFA CT UBING.
475
are sharp and distinct. A special close-grained cast iron is nec-
essary for such moulds. In use, the mould or "die" is placed
under the press and the shell to be swelled and decorated is filled
with water and enclosed within it. A plunger fitted to the ram
of the press, and fitting the opening in the top of the mould
tightly, descends and causes the confined fluid to swell out the
metal into the designs in the mould. This is a very economic
Plunger
Knurled Sleeve
FIG. 557.
way of producing decorated hollow ware, and is used almost to
the exclusion of all other methods in the large silverware estab-
lishments. To produce very plain figures, swells and shapes in
soft metals, a piece of soft-rubber is used as a swelling agent,
the plunger compressing it on the descent.
COMBINATION DIES FOR EMBOSSED WORK.
Flat, stamped, embossed, or raised sheet-metal articles are
usually drawn and stamped up in a first operation and trimmed
afterward in a plain trimming-die. Sometimes, when the de-
signs are simple or shallow, the articles are i^roduced in one
operation in a combination drawing and embossing die. This is
not done as a rule, as the metal is apt to draw and form un-
equally, and thus the finding of a blank which will draw up per-
fectly without fins or rough edges is very difficult. Again, the
two operations are combined in a progressive die, in which the
metal is first stamped and drawn, or vice versa, and then fed
along; and trimmed or blanked out.
476 TOOL-MAKING AND
MAKING "HOBS" AND SINKING EMBOSSING DIES.
In the making of embossing dies several methods are in
vogue. Sometimes both dies are made of steel, or one of steel
and one of copper or brass, or one of hard bronze and one of
soft brass, while for very large work of bold designs one die is
made of cast iron and the other of brass.
In making steel dies for striking up gold, silver, and other
valuable metals the first operation consists in carefully anneal-
ing the blank which is to form the master die or "hob," and then
getting a dead smooth finish on the face, which is then cut and
engraved and cut until an exact reproduction of the required de-
sign is raised on it. Careful engraving and scraping and giving
the proper amount of draft and radius to certain points will be
necessary in order to obviate the tendency of the metal to cut
apart while being worked; this will be most likely to occur
where perpendicular lines or surfaces are presented. After hav-
ing finished and polished all portions of the design the "'hob"
may be hardened and drawn to a deep straw temper. We now
have a master die or "hob" with which to sink the other die.
This "hob " is fitted to the ram of the press or of the drop ham-
mer, whichever it is to be used in.
We now secure another annealed blank, and carefully finish
the top and bottom. The master die is secured in the press ram
and the blank is placed directly under it. Both faces of the dies
are oiled and the master die is forced into the soft face of the
blank until a perfect impression of every detail and line in the
master die appears. This will require much time and patience,
it being necessary to remove the blank several times and cut
away the surplus metal thrown up. After the necessary amount
of clearance has been given the sunken die, and all points are
polished, it can be trimmed, faced and hardened, and tempered.
From this die a brass, bronze, or copper "force" is then struck
up, which is used in place of the master die in the production of
the articles desired. If many dies of the same kind are to be
made, such as for coins, a number of sets are sunk from the mas-
ter die, which is kept for that purpose alone; thus the exact
duplication of the design is assured in all the dies. For coins,
INTERCHANGEABLE MANUFACTURING. 477
of course, both dies are of steel. In coin dies the date, which
changes from year to year, is stamped in by hand after the im-
pression of the master die or "hob" has been struck.
In using a master die for making impressions the surfaces of
the "hob " and the blank should be kept well oiled and the press
should be turned very slowly by hand. By keeping the master
die for making impressions only, exact duplicates of the worn-
out dies may be produced, this being not possible by any other
method, as no engraver can exactly duplicate his work by hand.
When making very large steel dies by the method described
above it will be found necessary to drop the blank hot. Heat
the blank to a cherry red, drop the master die, remove the blank,
remove the scale, trim and work out the surplus stock, and then
re-drop cold. A perfect impression will be produced in this
manner.
BEONZE, BBASS, AND COEEEE DIES.
The making of bronze, brass, or copper dies for embossing
thin, soft sheet metal in shallow designs and shapes is usually
accomplished by first casting from wooden or modelled patterns,
and then taking a plaster cast of this, from which a mould or
matrix is secured which is carefully scraped and polished. This
matrix should be of hard brass or bronze, and the mould of much
softer metal, so that it may be forced or dropped into it until a
perfect impression appears. It will be found in dies of this kind
that the surfaces will wear surprisingly long, as they become
hard and tough through the dropping x>rocess.
It must always be remembered that in all kinds of engraved
dies a feature of great importance in their making is the neces-
sity of cutting deeper all depressions and fissures, so as to leave
all the higher portions in a position to be perfectly smooth and
polished. This is to prevent the marring or splitting of the em-
bossed side of the article.
For the production of ornamental tinware and other articles
in which the ornamentation is coarse and bold, cast-iron dies and
brass or hard babbitt moulds are used. These dies require little
labor or skill to produce, as the plaster casts or moulds for the
dies can be relieved in all deep places, and thus it is not neces-
sary to rout out the brass mould afterward.
478 TOOL-MAKING.
When the article required to be embossed is very deep, or
where the designs and ornamentation are much raised, it will be
necessary to accomplish the embossing with two sets of dies.
One set — the first — will have to be supplied with blank-holders
and a die having a rough outline of the required design. In this
die the metal will be drawn from between the blank-holders and
into the die, and a crude impression of the required design will
be given it. The article should then be annealed and struck up
perfectly in a finishing die. Not infrequently it will be found
necessary to use three, or even four, sets of dies to accomplish
the desired results in articles which are excessively deep. Trays,
salvers, picture frames and plates having ornamental borders not
too close to their edges, or circular articles with central raised
designs, can be blanked out and stamped or embossed in a com-
bination die in a single-action press, the die being equipped with
a spring buffer and a blank-holder ring, or in a double-action die
in a double-action press. Shallow shells, boxes or covers, either
circular or rectangular in shape, can be blanked, drawn, formed,
and embossed or panelled in a triple-action die in a double-action
press equipped with an automatic lower punch slide.
To fit the shanks of the embossing dies, upper and lower, or
to turn the outsides, clamp the punch or "force "and die to-
gether, and then machine as if one piece ; thus the perfect align-
ment of the embossing faces with each other when the die is in
use will be assured.
Although for years spoons, forks, and embossed metal handles
were produced under the drop hammer, this method has now be-
come almost obsolete, as the improvements in heavy automatic
presses and feeding devices for such has made their use for the
production of such articles quite general. These machines pro-
duce more and better work with less wear on the dies than the
drop hammer.
CHAPTER XXX.
The Modern Art of Swaging, Swaging Machines, and
the Cold Swaging Process.
THE HAMMER.
Man's first tool in shaping metal was the hammer, and with
the advancement in appliances, during the centuries, the ham-
mer has continued to hold its place. In modern metal working
Fig. 558.
Fig. 559.
the hammer is supreme. Its form, it is true, is changed from
time to time, but whether the hand tool or the power-driven
hammer is considered, the principles underlying its use are still
the same.
The simplicity and effectiveness of the hammer have never
been excelled in any other tool, nor even equalled. Whether
metal be worked hot or cold, the hammer is the king of tools.
Not only does the hammer produce a vast amount of work with
a small expenditure of force, but it gives to the metal qualities
which can be obtained in no other way. Strength, rigidity,
479
480 TOOL-MAKING AND
solidity, and increased elasticity are all gained under the ham-
mer, while in the cases of iron and steel a surface hardness is
secured which cannot be produced in any other manner.
SWAGING AND HAMMEBING.
Swaging, however performed, is only a kind of hammering.
The early smiths, it may be supposed, in the very infancy of the
race — certainly long before the dawn of history — observed in
working the metals with which they were acquainted, that the
face of the hammer always left its impression when a blow was
Fig. 560.— Pointing for Drawing.
struck. Any irregularity in the face of the hammer left a cor-
responding mark on the metal struck. To this fact, undoubt-
edly, does modern metal working owe both the art of swaging
and the art of die sinking, drop forging, and embossing, for the
fundamental principle in each is that of making a special face
for the hammer and another for the anvil.
These special faces for the hammer and the anvil are given
the form which it is desired to impress upon the metal, which is
to be struck between them. If the piece of metal which is to be
worked is, for example, cj^lindrical in form, the face of each,
the hammer and the anvil, is hollowed out, the depression being
given the required shape or design. The metal worked between
them is then forced by the blows applied into the hollows of the
two faces, thus taking on the desired shape.
While it may be supposed that the first swaging, crude though
it must have been, was performed between a hammer with a de-
pression in its face and an anvil with a corresponding indenta-
tion, it is probable that it was not very long before the early
smiths recognized the further fact that a great gain would be
made in such work by separating the special faces from the ham-
mer and the anvil, respectively. The hammer, therefore, was
INTERCHANGEABLE MANUFACTURING. 481
again made smooth and heated to be struck against a special piece
of metal or false face, to which one-half of the required form
had been given. The anvil, instead of being hollowed out ac-
cording to the design of swaging to be done, was made a large
solid block, heavy enough to resist the hardest blows, and pro-
vided with means to receive and hold a second special face, the
counterpart of that against which the hammer would be struck.
What are now known as swaging tools or dies resulted. All that
has been accomplished since has related to means of holding tools
to be operated, to means of imparting the necessary blows, and
to methods of controlling and guiding the work. In the follow-
ing the matter is a compilation from information kindly fur-
nished the author by the Excelsior Needle Company, of Tor-
rington, Conn., manufacturer of the Dayton swaging machine,
and the technical journal Machinery.
Strange to say, the ordinary dictionaries, in defining "swage "
in the sense of a swaging tool, take into account only one of a
pair as commonly used and as above described. One definition,
for example, is as follows: "A tool having face of a given shape,
the counterpart of which is imparted to the object against which
it is forcibly impressed. When used ... it is either placed
on the anvil so as to impress the metal which is laid thereon
and struck by the hammer, or the work being laid on the an-
vil the face of the swage is held upon it and the back of the
swage receives the blow." But modern processes of swaging,
work the metal on both sides or all around, as in the case of
a rod or tube, and for this purpose employ both top and bot-
tom tools.
The use of false faces to the hammer and the anvil, as above
set forth, or the use of swaging tools, as the corrected definition
describes them, and which are most commonly called "dies,"
enables a number of blows to be struck in obtaining the required
result, which secures an important economy of force, while also
rendering the operation less trying to the metal. There is like-
wise an important gain in the quality of the product. Further,
the employment of dies makes possible the use of a machine for
imparting the blows, in a way to secure rapidity of action and
absolute uniformity of work. The force of the hammer is trans-
31
482 TOOL-MAKING AND
mitted through the movable faces or dies without appreciable
loss ; in fact, with a positive gaiu in various points of effective-
ness.
THE COLD-SWAGING PROCESS.
The swaging process, although extensively used in certain
classes of work, is, as a machine shop operation, very little if at
all recognized. The success, however, with which this process
is employed for certain purposes would seem to indicate that its
use might be applied with profit to a great class of work that is
at present performed either by hot forging or by machining.
Cold swaging is the act of reducing or forming steel or other
material while cold, such as drawing to a point or reducing the
diameter of the work. This is performed by a machine which
causes the work to be struck a great number of successive blows
by a pair of dies of suitable shape to give the required reduction.
The process is mainly applied to reducing wires, rods, and tubes,
and is the only process by which rolled or plated stock can be
reduced without destroying the plating or coating. For this rea-
son it is largely used for jewellers' work, such as forming spec-
tacle templets, fancy pins, and similar pieces. It is also exten-
sively used for pointing rods or tubes which are to be drawn.
It will put the best point known to wire drawers, on a rod or
piece of wire in a fraction of the time that would be required by
any other method, and the same applies to its use on tubing.
The millions of needles, bicycle spokes, button hooks, crochet
needles, etc., which are turned out annually serve to show some
of the possibilities of the swaging process.
The possibilities of the swaging process are almost without
limit. The blacksmith through the ages has invented unnum-
bered applications found in daily use, while the modern ma-
chine builder has discovered various means of adapting swaging
methods to the rapid and economical production of numerous
shapes and forms required in the different trades and industries.
Eod-making in steel and iron, as well as the kindred trade of
making bars and axles, is essentially a swaging process. There
are modifications in the details of the machinery adapting it to
the purpose, but the principle is the same. In the same way the
INTERCHANGEABLE MANUFACTURING. 483
tapering of tubes both large and small is better performed by
swaging than by any other process. Modern swaging as a means
of reduction supersedes rolling, grinding, milling, turning, and
FIG. 561.
drawing, for the reason that it improves the quality of the mate-
rial and gives greater uniformity and better surface without
waste of stock.
One of a pair of tools or dies fastened in an anvil to hold the
metal to be worked, and the other sustained above it and adapted
to receive the blows of the hammer, constitutes one of the most
useful forms of swaging-machines. Substitute for the hand
hammer and its swinging blows a series of machine-driven ham-
mers revolving around the pair of dies which are suitably held,
and which deliver their blows in pairs upon the ends of the dies,
thus forcing them together and against the metal that is between
them, and a modern machine is produced the product of which
excels in character and value anything that has ever preceded it.
484
TOOL-MAKING AND
As an illustration of the saving of stock that may be accom-
plished by the use of this process, we, will consider a simple piece
of rod which is tapered from full diameter to a small point, as
Figs. 562 and 563.
shown in Figs. 562 and 563. In view of the piece marked A, the
dotted lines show the original piece of stock from which it would
be made if the work were done on a lathe or screw machine, by
Fig. 564.
the machining process, the dotted section showing the amount of
material that would be wasted. In the lower view B, the dotted
INTERCHANGEABLE MANTJFA CTURING.
485
lines show the amount of stock that would be required to pro-
duce it by the swaging process, and there would be no waste
whatever.
ROTARY SW AGING-MACHINES.
The rotary swaging-machine is now being made by a number
of manufacturers, and while the details of the different machines
vary in some respects, the principle is the same throughout.
Representative machines, made by swaging-machine builders,
are shown in Figs. 564 and 565.
The principle of the modern rotary swaging-machine is shown
in the line drawing, Figs. 558 and 559. Inside of the head in which
the spindle revolves is a set of hardened steel rollers B B B which
Fig. 565.
are fitted in recesses in the fixed casting, each of them being free
to run on its own axis. The front end of the spindle A is large
and has a slot across its face in which the hammer blocks slide.
These have recesses in their inner ends for holding the dies d d,
486
TOOL-MAKING AND
and in their outer ends are the rolls E E which are free to turn
when they come in contact with those in the head. As the spin-
dle revolves and the rolls in the die-blocks are brought into con-
tact with those in the head, the dies are forced together on to the
stock. After passing a set of rolls, the dies are thrown apart by
the action of centrifugal force, which keeps them separate until
the next set of rolls is encountered, when another blow results.
The machines are run at a spindle-speed of from 400 to 500 revo-
lutions per minute, and as there are eight rolls in the head, the
result is from 3, 200 to 4, 000 blows of the die per minute. The
work in these machines is not rested, as the rotation of the spin-
dle distributes the blow evenly around the circumference of the
Samples of Work Done with the Rotary Swaging Machine. '
1-2. Spectacle Temples (Steel) 7-8. Machine Needlesf Steel)
3. Fancy Pin (Rolled Stock) 9-10-11. Cotton Machine Spindles
i. Ring Body (Plated Stock) (Hard Steel)
5-6. Pin Tongues (Steel ) 12. Bitt ( Steel)
FIG. 566.
piece being operated upon. In another type of machine the
rollers are replaced by oscillating cams which, when they come
in line with the ends of the die- block, form a powerful toggle-
joint and bring the dies together with great screws which cause
the wedges back of the cams to slide in toward the centre.
Some samples of the work done with the rotary machines are
shown in Fis;. 566.
INTERCHANGEABLE MANTJFA CTTJB1NG.
487
THE DAYTON SWAGING-MACHINE.
The "Dayton" swaging-niachine, views of which are pre-
sented in Figs. 567, 568, 569, and 570, employs dies which are as
simple in their essential features as the most primitive swaging
tools. These dies, which are adjustable in their relation one to
the other, are carried in a slot in the face of a revolving mandrel,
and are held between a pair of blocks with rounded ends. On
the side of and around the mandrel is an annular rack containing
loosely a number of hardened steel rollers. The revolution of
FIG. 567.
Fig. 508.
the mandrel causes the dies and blocks with rounded ends to
pass between successive pairs of opposing rollers which force
the dies together. The mandrel is hollow to permit the work to
be fed through it. The dies revolve rapidly around the work,
which is stationary, while the rack containing the rollers revolves
very slowly, being moved only by the slight motion of the rollers
during the time of contact with the blocks. Accordingly, the
effect of the dies is very evenly distributed about the work.
The dies are blocks of hardened steel, which have formed
upon their inner faces the impression of the shape or the diame-
ter of the work it is desired to produce, with an enlargement or
flare at the outer or entering end large enough to allow the unre-
duced stock to enter. The dies are set up, or what is the same
thing, the blocks with rounded ends, or the backs as they are
called, are made to project more by placing thin plates of steel
between the ends of the dies and the backers. The dies and
backers are held in place in the slot in the face of the mandrel
by suitable plates.
Referring to the cuts, Fig. 567 shows a face view or front
488
TOOL-MAKING AND
elevation, with plates removed, and Fig. 568 a longitudinal sec-
tion of one of the smaller sizes of the Dayton swaging-machine.
The working parts of the several sizes are essentially the same,
so that a description of one will answer for all.
Fig. 569 shows the roll rack, face view, cross-section (one-
half), and side elevation (one-half).
Fig. 570 shows the face of the mandrel with the slot for re-
ceiving the dies and backers, also a sectional view indicating the
Fig. 569.
Fig. 570.
central aperture for receiving the work. There are also shown
the dies B in both side and end views and backers C. The plate
used for holding the dies in place is shown at D.
Eeferring again to Fig. 568 it will be seen that the balance
wheel, and fast and loose pulleys, are attached to the mandrel at
the back, and that the mandrel carrying the dies revolves within
the rollers B; also that the roll rack, held in place within the
cavity of the head of the machine by the plate F, is free to re-
volve as moved by the backers striking the rollers. The head of
the machine, which is of cast metal, is reinforced by a wrought -
iron ring, shrunk into it upon the outside, and by a hardened
steel ring on the inside.
The mandrel is adapted to be run at any rate of speed re-
quired by the work being done. With five pairs of rollers in
the rack, as shown in Fig. 569, there will be ten closures of the
dies to each revolution, varied only by the slight motion im-
parted to the rack by the backers striking the rollers. Eunning
at a speed of 400 revolutions per minute, therefore, the blows
upon, or closure of, the dies will approximate 4,000. The effec-
tiveness of the machine is thus made apparent.
INTERCHANGEABLE MANUFA CTUFING.
489
HOBIZONTAL SWAGING-MACHINES.
The horizontal swaging-machine was originally designed by
Mr. John Henderson, of Waterbury, Conn., and the first ma-
chines were built by him. Later, the manufacture was trans-
ferred to the Waterbury Machine Company, by whom this type
of machine is now manufactured. The horizontal is especially
designed for work of a heavy nature, such as is encountered in
mills where rods and tubing are manufactured. It is constructed
on a principle entirely different from that of the rotary machine.
Fig. 571 shows a machine of this type. The round hole at the
left, in line with the upper bearing, is the opening where the work
is introduced. The centre of this hole marks the place where the
dies are split on the vertical line. One-half of the die is backed
up directly against the heavy casting of the frame, and the other
half, toward the bearing, has a reciprocating motion on the hori-
zontal line. The means by which this motion is obtained will be
seen by reference to Fig. 571.
The lower main shaft A carries the balance wheel and has a
crank of short throw between the bearings, while the upper shaft
B, of large diameter, has a crank with a throw about six times as
great. A connection C joins these two cranks; it will turn the
Fig. 571.
upper shaft through but a portion of the circle. If a line be
drawn through the centre of this upper shaft, so that it is hori-
zontal when the shaft is in the middle portion of its turn, it will
follow that this shaft will have a rocking motion about its cen-
tre, and the diameterically opposite points where this line meets
the periphery of the shaft on either side will each pass the centre
twice for every revolution of the pulley. If, now, a system of
490 TOOL-MAKING AND
horizontal toggles be interposed between the reciprocating block
and the frame casting at the right, in which system the middlle
block passes through the shaft, it will follow that by the rocking
motion of this block the distance between the extreme ends will
increase and decrease twice per pulley revolution, or, in other
words, the number of blows will be twice the speed of the pulley.
A spring, not shown in the cut, is used to separate the dies be-
tween the blows.
These machines reduce up to 2-f inches in diameter and tubes
up to 4 inches, and the amount of reduction ranges from ^ to
\ inch for rods and -§■ to -j inch for tubes, depending upon the
diameter and nature of the material. Where a much greater re-
duction is required than can be made by passing the work once
through the dies, it has proved a great convenience to use a ma-
chine with three sets of dies which gradually decrease in size.
This is brought about by lengthening the machine out at the left-
hand end for two extra pairs of dies, and as but one pair is
in use at a time, motion is transmitted from one set to the
other, all having a sliding fit in the opening. The form of the
die is a cube, so that four faces may be used as required, the
dies being turned around to bring similar half -openings together.
When small diameters are required, several sizes can be cut on
each face, and the changing from one size to the other is but the
work of a moment.
While the machine is principally designed to point rods and
tubes for subsequent drawing through dies, it has numerous
other uses, such as flattening round stock to a desired shape with-
out waste of material. In this way it has been successfully ap-
plied to shaping ends of rods for screw -driver blades, the round
rod being merely pushed into the opening and the finished article
withdrawn without any fin or waste. Many other o}3erations of
a similar nature may be performed, and in this class of work it
covers a ground not practicable with any other type of machine.
SOME EFFECTS ON WORK ACCOMPLISHED BY
SWAGING.
The work performed by the swaging process is done by press-
ure rather than by blows. Accordingly, there is a flow and re-
INTERCHANGEABLE MANUFACTURING. 491
adjustment of the molecules of the swaged metal, the effect
of which extends equally throughout the piece in a manner to
strengthen it and add other desirable qualities. To perceive the
adaptability of the machines to a very wide range of work, from
articles of the smallest dimensions up to those of a considerable
size, requires only an acquaintance with the principle upon
which they operate.
CHAPTER XXXI.
PROCESSES AND METHODS FOE, THE WORKING
OF ALUMINUM.
ALUMINUM VS. OTHEE MEDALS.
The innumerable uses to which aluminum has been put dur-
ing the last few years, and the large variety of articles — from
kitchen utensils to drop forgings — now produced from its vari-
ous alloys, promise that the "beautiful white metal " is destined
to be very extensively employed. Sheet aluminum, at least, is
replacing the other metals, as experiments have determined that
it can be worked as expeditiously and economically as the older
commercial sheet metals. It can be worked, when of a proper
alloy, as easily as sheet brass, German silver, or tin-plate, and in
numerous instances — when the tools have been made correctly
and the metal is lubricated properly while working — it can even
be worked more cheaply than any of the other sheet metals.
DIFFICULTIES ENCOUNTEEED IN WORKING.
The most serious difficulties to be encountered in working
aluminum are "hooking-in," clogging and squeaking, in drill-
ing; tearing and "gouging-in, " in milling and planing; "jam-
ming" up or blocking of punchings in dies, and consequent
breaking of punches; the cohesion of fine particles of aluminum,
compressed hard, to the cutting-edges of punches and inside of
dies, and on bending or forming dies scratching the aluminum ;
parting or breaking the metal in drawing it.
PUEE METAL VS. ALLOYS.
One thing that a great many mechanics are not aware of is,
that aluminum should hardly ever be used in its pure state.
Many of those who have experienced difficulties in working the
metal have been using the pure metal instead of a suitable alloy.
492
INTERCHANGEABLE MANUFACTURING. 493
A majority of the aluminum alloys compare with the pure metal
about as brass compares with copper, and as brass can be worked
more easily than pure copper so aluminum alloys can be worked
more easily than pure aluminum. One has only to gaze at the
variety of articles and novelties which may be found in a shop-
window or on a department-store counter, and to note their
cheapness, to understand that there can be no great difficulty in
working the metal into any shape that any sheet metal will flow to.
SECRETS IN THE WORKING OF ALUMINUM.
The two great secrets— that is, if we may term them secrets —
in the working of aluminum, either in its pure state or in any of
its alloys, is the use of a proper lubricant, and in the proper
shape of the cutting-edges of the tools.
GRADES AND ALLOYS OF SHEET ALUMINUM.
There is a great variety of grades and alloys of sheet alumi-
num on the market, so numerous that no difficulty should be ex-
perienced in producing that suitable for any special purpose.
Aluminum may be had in much the same variety as sheet brass,
or in all degrees of hardness, from dead annealed stock to the
pure, stiff, springy aluminum. Next to the pure metal is a hard
grade of alloys, ranging from dead soft stock, which will spin,
draw, or form up hard and stiff, to the same grade hard rolled.
After that comes another set of alloys which are replacing sheet
brass in a large variety of kitchen utensils, novelties, parts of
instruments, mechanical appliances, and the lithographer's stone.
Lastly there is another grade of alloys which has been perfected
lately from which great things may be expected, which are begin-
ning to be used for drop-forgings. Experiments have shown
that drop-forging can be accomplished with this metal more
easily and satisfactorily than with many others, because certain
alloys of aluminum can be worked cold.
WORKING THE METAL.
Now about working the metal. In turning, milling, or drill-
ing aluminum in its pure state more difficulty has been experi-
enced than in the press-working of the sheet metal. All these
494 TOOL-MAKING AND
difficulties disappear if the tools are made properly and the right
lubricant is used. The tool should be made with lots of top
clearance and bottom rake, and instead of the stub point, as used
for brass, it should be lengthened out. The top clearance
should be sufficient to allow the turnings to free themselves
easily and not clog around the point. Lastly the tool should be
tempered at a light straw, and stoned to a keen edge.
LUBRICANTS TO USE.
As to the best lubricants to use for the machine operations
of turning, milling, or drilling, crude oil is best for milling and
kerosene for drilling ; while for turning, soap water, and plenty
of it, will give grand resuls. A few years ago a large number
of small electric cloth-cutting machines were being built under
my supervision, the motor eases,, brackets, standards, and bases
of which were castings of aluminum, all of which had to be ma-
chined all over to interchange perfectly. A number of fixtures
were constructed for their production, which were described and
illustrated by the writer iu a series of articles in the columns of
the American Machinist during September and October, 1900,
under the title of "Tools for Interchangeable Work." I had to
do a great deal of experimenting to produce the parts to the re-
quired degree of finish and interchangeability. All sorts and
shapes of cutting tools were tried and different lubricants were
used. It was found that drills, counterbores, reamers, centres,
and turning tools would work beautifully when iots of clearance
was given them, the edges being well hardened and then stoned
to a keen edge; that soap water was the best lubricant for drill-
ing, and for large counterboring a cheap grade of vaseline.
With the crude oil for a lubricant in milling, butt mills, \ inch
in diameter, were used to take deep, wide cuts without undue
strain on the teeth, without the cuttings clogging ; and, instead
of a coarse, torn texture resulting, a shiny, smooth finish was
the pleasant attainment. In one large shop in Brooklyn, which
makes specialties of lithographing presses, bronze machines, and
bronze lithographing dusting machines, they formerly used large
numbers of brass brackets for the grippers on the presses, but
now they use aluminum castings.
.INTERCHANGEABLE MANUFACTURING. 495
CUTTING DIES FOE ALUMINUM.
In cutting dies for aluminum there should be at least one de-
gree clearance. If the blank is over y 1 -^ inch thick and a smooth,
uniform edge and exact size of blank are required, it should be
recut or " shaved " in a second die, which should be made straight
on the inside cutting edge for not more than the thickness of one
block — or two at the most — in order that the die may retain its
exact size after re-sharpening. Allow about 0.01 inch on the out-
side of the blank for shaving to ■£ inch of thickness, but if the
blanks are of hard aluminum alloy, half that amount will be
sufficient.
The cutting-edges of both punch and die should be sharpened
very smoothly after grinding with an oil stone.
Lard oil or melted Eussian tallow, the best for lubrication,
should be used on both sides of the metal.
Punches and dies should be carefully cleaned occasionally of
the fine particles of aluminum that will be found adhering to the
edges.
DEA WING-DIES FOE ALUMINUM.
In drawing aluminum of a thickness not more than -^ inch
and a depth of draw more than ^ inch, to avoid the tearing or
wrinkling of the blank it should be held between a ring sup-
ported on pins and springs and the face of the punch, rather
than between the edge of the forming cavity of the punch and
the sides of the forming-block, as is the case in a draw-plate die;
but, however it may be held, after it is drawn up first in U-shape
—redrawing several times if necessary in ordinary draw-plates
and plungers — care must be taken not to employ too fast a speed
in the operation, or the work will break at the bottom through
too sudden impact.
If the aluminum to be drawn is thicker than -g^ inch, it can
be drawn direct, without the spring ring mentioned above, to a
depth of f inch, or even deeper, the exact depth depending
largely of course upon the composition of the aluminum alloy,
the shape of the article to be produced, the finish on the dies,
and the speed of the press.
496 TOOL-MAKING AND
Aluminum is not a suitable metal to work in compound or
sub-press pieces, as the number of pieces of this metal that can
be punched out without putting the dies out of commission by
clogging* and consequent breaking of punches will not be suffi-
cient to pay for the cost of the tools.
DBA WING ALUMINUM SHELLS.
For the drawing of aluminum shells, tools of the same con-
struction as those which are used for the production of brass or
tin ones should be used. One peculiarity of aluminum which
manifests itself when drawing the metal is that one cannot ob-
tain as great a depth with it in one operation as can be done
with brass. This is because the tensile strength of aluminum is
somewhat less than that of the other metal. It may, however,
be drawn deeper without annealing than any other commercial
metal. An article made of brass requiring, say, three or four
operations to complete, must usually be annealed after each re-
drawing operation ; conditions, such as the thickness of the stock,
depth of draw, etc., determining this. With aluminum, how-
ever, if the proper grade is used, it will often be found possible
to perform the entire number of operations without annealing at
all, or at most once. At the same time a finished shell will be
produced which will be equal in every way to one made from
sheet brass.
BENDING AND FOBMING DIES FOB ALUMINUM.
Bending or forming dies for aluminum should have all the
friction parts very smooth and polished in the direction of the
draw or bend ; that is, the grain of the die and punch should be
in the direction in which the metal travels in the die. Lard oil
should be used on both sides of the work.
SFINNING ALUMINUM.
In spinning aluminum, best results are obtained by employ-
ing a high speed, with a light pressure of the spinning tool,
evenly and gradually applied. Aluminum may be stamped
under a drop-hammer with about the same weight and momen-
tum as required for silver.
INTERCHANGEABLE MANUFACTURING. 497
ANNEALING ALUMINUM.
Articles of aluminum may be easily annealed by heating in
an ordinary muffle, taking care not to get the temperature too
high. The proper annealing heat lies between 650 and 700 de-
grees Fahr. The best test for the heat is to take a soft pine stick
and draw it across the metal. When the wood chars and a black
mark is left on the metal, it is sufficiently annealed and is in the
proper condition to proceed with the further operations.
POLISHING AND FINISHING ALUMINUM.
Next to the working and machining of aluminum the most
important processes lie in the polishing and finishing of it.
After the articles have been produced, a fine polish can be given
them by first using a rag buff treated with tripoli to cut down
with. The high finish can then be attained by using a dry rouge
that comes usually in lump form, first grinding it to as fine a
powder as possible. The tripoli also should be very finely
ground.
For a great many manufactured aluminum articles a frosted
surface is desirable. This is usually done by scratch -brushes made
of brass crimped wire of, say, No. 31 to No. 34 B. & S. gauge.
Three or four rows of bristles will do. To lessen the work of
scratch -brushing, the metal may be first cut down with a por-
poise-hide wheel and fine Connecticut sand, the sand being fed
between the surface of the wheel and the article. By using this
latter method first, the skin, pimples, and all surface irregularities
are removed, and the scratch-brushing is made easy. When the
worked metal is smooth and of good appearance the cutting
down with tripoli will be all that is necessary, after which the
rouge may be used as described, and tiiQ finished surface put on
with the scratch-brush. By taking the preliminary precautions
the scratch -brushing will frost the metal quickly and uniformly.
Another way of obtaining a similar effect to that of the
scratch-brush is by sand-blasting. This is usually done to the
sheets before working them, first sand-blasting and then scratch-
brushing. The effect remains after the articles have been drawn
32
498 TOOL-MAKING AND
up, as the metal works in much the same maimer as lithograph
sheets would, in the working of which, as is well-known, the
designs are not marred.
There is still another method for producing a very pretty
frosted effect on aluminum. It consists of first sand-blasting
and then frosting by "dipping." A great many varieties of
finish on aluminum can be obtained by suitable combinations of
these treatments.
To secure a pretty mottled effect on aluminum the article
should first be polished, then the scratch brush-applied, and then
the surface burnished with a soft pine wheel which should be
run at a very high rate of speed. By careful manupulation regu-
lar or irregular patterns of mottling can be obtained.
The cheapest and most economical way of producing articles
with finished surfaces from the sheet is to treat the sheets as
follows : After removing all grease and dirt from the metal by
dipping in benzin, cleanse in water until the benzin has disap-
peared, after which the plates may be dipped in a strong
solution of caustic soda, or caustic potash, holding them in the
solution until they commence to turn black. Then remove the
sheets, dip again into water, and then into a solution of concen-
trated nitric and sulphuric acids. After removing from this
last bath, wash the sheets thoroughly in water,, and dry in hot
sawdust. The finish on the plates can be varied by varying the
strength of the caustic solution, or by adding a small quantity of
salt to the full -strength solution.
BUKNISHING.
For articles which require to be burnished a steel burnisher or
a bloodstone will give the best results. When burnishing the
use of a mixture of melted vaseline and crude oil as a lubricant,
or a solution composed of three tablespoons' of borax dissolved
in a quart of hot water with a few drops of ammonia, will add
to the finish of the work.
ENGEAVING AND CHASING ALUMINUM.
A great deal of engraving is now being done on aluminum,
such as on finished picture-frames, cups, trays, book-covers,
INTERCHANGEABLE MANUFACTURING. 499
match-safes and similar articles, and for this work the best lubri-
cant to use on the tools is naphtha or crude oil. A mixture of
crude oil and vaseline also is good. However, the naphtha will
be found the best, as it will not affect the satiny finish around
the edges. Besides the use of a proper lubricant when engrav-
ing aluminum, considerable skill is necessary in the making and
use of the cutting-tool. A tool made similar to a turning tool
for aluminum, finished to a sharp, keen point with lots of clear-
ance, will work excellently.
A property that makes pure aluminum very valuable for
many purposes lies in its ability to withstand the action of acids.
While the metal is easily affected by alkalies, the strongest
acids do not injure it to any noticeable extent — in fact, acid acts
on it in much the same manner as on platinum. For parts of
apparatus which have to be immersed in strong acids for consid-
erable periods, parts of aluminum will prove highly efficient.
One use to which the metal has been put in this respect is for
hooks for removing photographic negatives from the acid baths.
Acid funnels of aluminum also have proved a boon to many.
SOLDEEING ALUMINUM.
The last, but not by any means the least valuable, process in
the working and use of aluminum is soldering. To many the
difficulties experienced in this line have proven a great detri-
ment to the successful use of the metal for many purposes. The
uncertainty as to the best solder to use has been one. There are
any number of solders which have proved fairly successful when
skill has been employed in using them. The following has
proven to be the best in practice for soldering the pure metal or
any of its alloys : Fuse together one pound of block tin, four
ounces of spelter, two ounces of pure lead, three pounds of
phosphor tin. With benzin clean all dirt and grease from the
surfaces of the parts to be soldered and then apply the solder
with a heated copper "iron." When the melted solder covers
the surfaces completely, scratch through it with a wire brush,
which will break the oxide and take it up. Spread the solder
again with the iron and allow to cool. When it is found neces-
sary to "sweat" aluminum parts together, first clean the surfaces
500 TOOL-MAKING.
as described for soldering, then heat the parts until the solder
flows freely over them, scratch through with the wire brush,
wipe with clean waste, and clamp together. A first-class joint
will result.
ALUMINUM AS AN ABEASIVE.
Aluminum, despite its metallic character, can be used as an
abrasive for sharpening knives. It has the structure of a deli-
cately grained stone, and under friction gives an extremely fine
mass which adheres powerfully to steel. Consequently, blades
sharpened on aluminum rapidly take a thin, sharp edge which
cannot be produced by the best stones. If knives are passed
with utmost care over a razor stone, the edge, when magnified
1,000 times, shows irregularity and toughness, while edges pro-
duced on aluminum, when submitted to the same examination,
appear perfectly straight and smooth.
CHAPTER XXXII.
Hints, Kinks, Ways, and Methods of Use to Tool-
makers and Die -makers.
NOTES ON CIRCULAR FORMING TOOLS.
When making circular forming tools always keep the fact in
mind that the diameter has much to do with their wearing quali-
ties; and that unless their diameter is proportionate to the diam-
eter of the work satisfactory results will be hard to obtain.
In Fig. 572 are shown two circular tools of H and 2 inches
diameter, respectively, both cut out ^ inch below centre, as they
would be if intended to operate on the front side of the machine
D
Fig. 572.
or at the back side with the work running backward. Although
shown in this position, the principle involved is of course the
same as though the tools were placed the other side up, the tool-
post being bored out above the centre-bore of work spindle, in-
stead of below, as in the case referred to.
Referring to Fig. 572 it is easy to see that the cutting-edge of
the larger tool would have much greater endurance than that of
the smaller, the rake or clearance of the latter being excessive.
This difference of rake in circular cutters must of course in-
crease with the difference in diameter of the cutters, provided
the cutting-edges are located at the same distance from centre.
The case is similar to that in Fig. 573, where are shown side by
501
502
TOOL-MAKING AND
side two straight cutting-off tools, the clearance of one ground
as at E and the other as at F. The angle of clearance of B is
practically the same as that of the larger circular tool in Fig.
Fig. 573.
574, while that of F coincides with that of the smaller tool and
shows much less durability than the tool ground as at E.
It is usually the best practice in making tools for a certain
size machine to keep them as closely to one diameter as possible.
In the larger machines cut out the tool T \ inch from centre,
and of course bore the tool-post a corresponding amount above
or below the centre, according to which side up the tool is to be
D
Fig. 574.
operated. For the smaller machines make the tools of less diam-
eter, cutting them out £ inch from centre and boring the post to
correspond. In Fig. 574 line A B represents centre of work, CD
centre of large cutter, showing the same cut T 3 g inch below cen-
tre, while G D represents centre of small cutter and shows the
same cut £ inch below centre. The clearance of both cutters is
practically identical.
A KINK FOE DEAWN WORK.
A sharp corner under a shoulder or flange is often a very de-
sirable thing, and one generally considered impossible in drawn
INTERCHANGEABLE MANVFA CTUBING.
503
work because of the necessity of a round corner on the die to keep
the metal from tearing- while being drawn through the die. There
is a method, however, of doing this that is quite successful, as
shown by the accompanying sketch, and it seems to be about the
only way it can be done. The "kink" consists in making the
punch a series of steps as per Fig. 575, with round corners instead
of a parallel one, as in the usual j)ractice ; the steps to be about as
far apart as the depth to be drawn ; and the difference in diame-
ter of steps to be determined by thickness of stock. The blank,
instead of being a round disk, is a washer, the outer edges held
not too tightly by the usual pressure ring or plate, and the end of
the punch to be a little larger than the hole in the washer. The
' ' 'in
SECTION OF DIE
V//////////////.-::'//-'':'-[ -PR£SS{JRE RING
" -DIE PLATE
Fig. 575.
punch will open the hole to the full diameter of the end and turn
the sharp corner of the disk in the most surprising manner. The
steps follow each other rapidly, each one enlarging the hole to
its own size and carrying the stock down through the die, the
last step being the finished size of the interior of work, and the
hole in the dies being the outside diameter of same. A die like
this needs a press with a good long stroke, dej)ending, of course,
upon the character of the work.
BEASS-WOEKEN T G TOOLS AND THEIE USE.
Figs. 576 to 583 illustrate brass- working tools for hand
work. No. 576 is a flat planishing tool which is used for finish-
504
TOOL-MAKING AND
iug and smoothing down flat surfaces, and also convex surfaces.
No. 577 is a flat planisker, ground at an angle so as to allow of
getting into a corner. Nos. 578 and 579 are for finishing in round
corners or roughing concave surfaces. No. 580 is a small round-
nose tool which is generally used for roughing out work or get-
FiGS. 576 to 583.
ting under the scale of a casting. No. 581 is the proper form
of hand cutting-off or parting tool. None of these tools should
have any top rake; on the contrary, they should be ground
Figs. 584 to 591.
slightly the other way and carefully stoned on an oil stone.
Nos. 582 and 583 are hand thread chasers, which are respectively
for outside and inside threads.
The tools shown in Figs. 584 to 591 are for use in the Fox
lathe. The hook tools which are used in the back head of the
machine closely resemble the regular inside tools, except that
the point is turned the other way for outside work. Sometimes
INTERCHANGEABLE MANUFACTURING. 505
a tool-holder similar to that shown with set-screw is used with
small inserted cutters. Give these tools no top rake and no
difficulty will be encountered in their use.
By grinding a twist drill as indicated at B all danger of
drawing-in will be avoided ; that is, grinding the lips flat for a
short distance. On a small drill the whole point may be ground
flat to obtain the best results.
The flat hand drill illustrated is the best for rough-boring a
hole in a solid piece. A series of such are used for taper holes,
the larger being used first and the others following to the proper
depth to make about the required taper. This is then reamed
out to the exact taper with various tools. A flat reamer is often
employed with good results, especially for roughing. For finish-
ing it is very apt to chatter unless packed on each side with a
piece of hard wood of about the right shape to conform to the
hole. Sometimes a reamer with a single large flute, as shown, is,
used with good results. It is relieved nearly all the way around.
For finishing, it is hard to beat the old reliable square reamer
as shown at 590. This reams a nice smooth hole as it fills up
with chips enough to prevent chattering, and it starts well if
carefully ground and honed on an oil stone.
GRINDING TWIST DRILLS FOR CUTTING A SECTION
OF A HOLE.
In order to drill holes in which part of the drill has to cut a
section of a hole as shown in the sketches Figs. 592 and 593 the
drill should be ground as shown in Fig. 593. It will then be
found as easy to drill the holes straight as if drilling a full hole.
To start the drill, use an ordinary drill, drilling just deep
enough to enter the blades of the drill as ground in Fig. 593 ; or
a jig may be used to guide the drill in starting.
TURNING AND TRUING RUBBER.
The medium-hard compositions of rubber work very nicely
with a diamond-point tool, ground a little round on the point
and given a sharp rake. The tool should be hardened very hard,
as there is sufficient fine grit in the rubber to wear the edge
506
TOOL-MAKING AND
badly. The speed is governed by the ability of the tool to stand
up to the work, and is slower in proportion as the rubber is
harder.
Soft-rubber articles cannot be cut satisfactorily with any kind
of a tool ; the best and quickest way is to grind them down. In
fact, grinding makes the most satisfactory job, whether the rub-
ber is hard or soft.
The grinding may be done in a lathe, using an overhead drum
for driving the wheel and bolting the wheel arbor to the tool-
post block.
In plants where electricity can be had a small direct-con-
nected motor, with flexible cord and plug, makes the most con-
FiG. 593.
venient drive, as it is readily detached and put away when not
in use, leaving plenty of head room over the machine, a quite
important detail in shops where most of this work is done, and
where one or two lathes have to do all the work, large and small.
The best results are obtained by using cast-iron disks for
wheels, 8 to 10 inches in diameter and 1\ inches thick, with a
groove 1 inch wide and ^ inch deep turned in the face. This
groove is filled with strong twine, laid on tight in hot glue and
then covered with several coats of glue and No. 40 emery.
These wheels are to run dry.
INTERCHANGEABLE MANUFACTURING.
507
PATENT TOOL-HOLDERS.
Figs. 594 to 600 show a complete set of the tools that with a
straight tool-holder will accomplish all ordinary lathe work.
In grinding these tools always take them out of the holder,
otherwise they will be too heavy and liable to heat when placed
against the emery wheel. If the cutter alone is held in the hand
<^s
FIGS. 591 to 600.
it gives timely warning, by becoming too hot to hold comforta-
bly, and is cooled off before it gets hot enough for the temper to
be drawn.
HARD-SOLDERING.
In the operation of hard-soldering, if the action of heat and
the nature of the metals in hand are understood, there should be
no trouble in obtaining a good sound joint, provided the proper
facilities are available. Jewellers, as a rule, are very painstak-
ing in their preparatory work, rubbing borax paste upon slate,
exercising great care to avoid touching the joint with the hands,
so as to have chemically clean metallic surfaces, etc. This is all
correct, theoretically, but some machinist workmen also pay all
attention to these details, and yet lose sight of the more impor-
tant fundamental principles, especially those pertaining to tem-
perature. In a large portion of the hard-soldering to be done in
the average shop, the observance of these minor details first
referred to would involve considerable trouble. These may be
safely ignored to a large extent if the applications of flux, solder,
and temperature are properly made.
Have the joint as tight as possible, to prevent the solder from
running through without filling. Apply the flux paste before any
heating is done, and do not put the solder on until the work is
about a low red heat, depending on the character of the work,
508 TOOL-MAKING AND
metal, shape, etc. Apply the heat to the joint rather than to
the solder, and if the solder runs immediately as it is used, have
no fears as to the success of the job. In cases where a joint can-
not be drawn tight, fill up with wire, scrap metal, fillings, etc.,
of the same metal as the work. This may also be applied to the
outside of the joint if it is desired to retain solder for reinforce-
ment.
If these rules are adhered to, it will be unnecessary to mix
your flux paste on slate, and slight fingering will not prevent
the making of a good joint. However, cleanliness is a trait to
be cultivated, and is desirable in all soldering operations. If
the joint is not reasonably clean, solder will not flow readily,
more being required to dispel or vaporize the grease or other
foreign matter.
SPEED OF PULLEYS AND GEAES.
In any system of pulleys or gears the general rule holds that
the product of the diameters or number of teeth of the driving
wheels and the number of revolutions per minute of the first
driver must equal the product of the diameters or number of
teeth of the driven and the number of revolutions per minute of
the last driven wheel.
The most frequent pulley calculations in the machine-shop re-
late to the speeds of machines and countershafts, for which we
have the four following rules, based upon the above principle.
First, speed of pulley on machine given, to find speed for
countershaft. Multiply the number of revolutions per minute
of the machine pulley by its diameter and divide this product by
the diameter of the driving pulley on the countershaft.
Second, speed of countershaft given, to find the diameter of
pulley to drive machine. Multiply the number of revolutions
per minute of the machine pulley by its diameter, and divide
the product by the number of revolutions per minute of the
countershaft.
Third, speeds of main shaft and of countershaft given, to find
diameter of pulley on countershaft. Multiply diameter of main
pulley and divide by number of revolutions per minute of coun-
tershaft.
INTERCHANGEABLE MANUFACTURING. 509
Fourth, speed of countershaft given, to find diameter of
pulley for line shaft. Multiply number of revolutions per min-
ute of the countershaft by the diameter of the pulley belting
with the main line, and divide the product by the number of
revolutions per minute of the line shaft.
ETCHING STEEL.
For etching names, dates, designs, etc., in steel, use any of
the following recipes:
No. 1. — Iodine, 2 parts; potassium iodide, 5 parts; water, 40
parts.
No. 2. — Nitric acid, 60 parts; water, 120 parts; alcohol, 200
parts ; copper nitrate, 8 parts.
No. 3. — Glacial acetic acid, 4 parts; nitric acid, 1 part; al-
cohol, 1 part.
BOEING LONG CAST-IRON TUBES.
When boring long cast-iron tubes of large diameter — say 15
inches — excellent results may be attained by using kerosene as a
lubricant, and a "packed bit" of the type used for gun-boring.
Holes of the smoothness of glass will be the result.
TINNING CAST IRON.
The following tinning for cast iron will turn out whiter and
harder than that with tin alone : Iron, 6 parts ; tin, 85 grammes ;
nickel, 9 grammes. Dissolve the three metals in hydrochloric
acid. This alloy will adhere well to the cast iron and present a
very brilliant surface.
All tanks used for pickling cast iron in vitriol should be lined
with lead and the seams burned together, not soldered. When a
pickling tank is lined with zinc it will last but a short time
under the action of the acid. Solder is also acted upon.
A HANDY DIE AND TOOL-MAKER'S CLAMP.
In Fig. 601 are shown sketches of a very handy clamp. It
may be used for many purposes other than the one indicated.
In this case it does away with the making of templets in die-
510
TOOL-MAKING AND
making after the master blank has been made. First, the exact
centre of the die blank is found ; then the blank is placed in its
proper position on the face and clamped there as shown in the
sketch. Then the outline of the blank is scribed.
The clamp may also be used to hold the steel block for the
Fig. 601.
punch securely against the die face ; thus facilitating the turning
of the work to the light and examining the inside.
LUBRICANT FOR DRAWING SHELLS.
Take one pint of common lard oil, two pounds of opodeldoc
soap, eight gallons of water ; steam or heat until warm. Attach
a square pan to the front of the press and keep the shells well
covered. With very small shells, such as primers or pencil tips,
it will be necessary to keep the solution warm ; but with large
shells this will not be necessary. This is the best lubricant for
drawing shells from thin metal that I have ever come across.
TO GLITE LEATHER TO IRON.
To glue leather to iron, paint the iron with some kind of lead
color, say white lead and lamp-black. When dry, cover with a
cement made as follows : Take the best glue procurable, soak it
in cold water till soft, then dissolve in vinegar with a moderate
heat, then add one-third of its bulk of white pine turpentine,
thoroughly mix, and by means of vinegar make it the proper
consistency to be spread with a brush. Apply the cement while
INTERCHANGEABLE MANUFACTURING. 511
hot ; draw the leather ou or around quickly, and press tightly in
place. In case of a pulley, draw the leather around tightly as
possible, lay and clamp.
KEEPING NOTEBOOKS.
Before concluding this chapter I feel that it will be well to
present a few remarks on the advantage of keeping note-books
in which to note and preserve the valuable and useful informa-
tion which abounds in the mechanical press and which one be-
comes informed of through association with brother mechanics,
or through experience and practical observation. It is a fact
that the diffusion of knowledge is retarded greatly by mechanics
in general trusting to their memory for the preservation of valu-
able information, instead of to more reliable means.
The most simple way to gain by one's reading and observa-
tion is to determine to fix upon some plan within one's capacity,
means, and opportunity — those which come in one's daily routine
— and to follow it j>reseveringly, regularly, and punctually, as an
important factor in one's daily duties. Many men owe their suc-
cess in life to the keeping of note-books in which they had noted
information which, while of little moment at the time when writ-
ten, proved of inestimable value at a later date.
A good way is to keep three note- books : one for jotting down
items and notes and sketches which come to one in the shop
through observation, hearsay, and experience. This book should
be of pocket size. The second book should be a large, strongly
bound manuscript book having horizontal ruled lines. In this
one can write something every evening — something one has read
in a mechanical paper. The third book may be a scrap-book of
the usual kind, in which sketches, small drawings, diagrams, and
illustrations of new machines and appliances may be pasted. By
following this suggested plan one will become a close and accu-
rate observer, an enlightened and well-informed man, and a bet-
ter mechanic ; no matter what line he is engaged in, he will not
only gain in knowledge, but may gain financially by publishing
in the mechanical press any information which has come to him
through experience and observation and which appears to be
new or novel.
CHAPTER XXXIII.
The Value of Up-to-date Fixtures and Machine
Tools. — Conclusion.
In the preceding chapters I have endeavored to illustrate and
describe the most approved construction and methods for accom-
plishing the best results in modern tool-making and interchange-
able manufacturing ; and before drawing this work to a close I
have thought it fitting to conclude by discussing the value of im-
proved and labor-saving fixtures and machines, and to present
what to me appears to be the only system by which the Ameri-
can machine-shop or manufacturing plant can retain its place at
the head of the world's list of industrial supremes.
LACK OF KNOWLEDGE OF MACHINE TOOLS.
Notwithstanding the vast amount of literature that is being
circulated to-day describing and illustrating the uses of new
machines, appliances, etc. , for economic manufacturing, there is
a woful lack of knowledge among shop managers, superintend-
ents, and proprietors as to their possibilities, and among me-
chanics of how to operate them properly. If any one has an ex-
cuse for this lack of knowledge it is the mechanic ; for while the
heads of establishments are constantly receiving printed matter
describing what the machine can do, and have representatives
calling on them to discuss the labor-saving features of the ma-
chines they are selling, the mechanic has to rely solely upon the
knowledge gained previously in the running of other similar
machines to assist him in mastering the details in the operation
of the new one.
"UP-TO-THE-MINUTE" MACHINE TOOLS
To-day the amount of money and time that is wasted every
day in shops is apparent to very few. Even superintendents,
shop managers, and master mechanics fail to realize the economy
512
INTERCHANGEABLE MANUFACTURING. 513
that can be effected in the production of duplicate metal articles
and interchangeable machine parts and the increasing of the effi-
ciency of the output, by replacing worn-out and obsolete ma-
chines with others that are "up-to-the-minute," equipping them
with suitable fixtures and tools, and operating them as they were
designed and built to be operated.
ADVANTAGES GAINED THROUGH THE USE OF
IMPROVED TOOLS.
It goes without saying that the most important item in the
cost of running a modern machine shop or a manufacturing plant
is the labor bill. The tools and machines in the hands of and
operated by the workman determine the size of the output to a
given size of labor account. Thus the advantages to be gained
in manufacturing by the use of up-to-date machines and special
tools and fixtures are obvious; as the cost of the machines and
the amount expended in the designing and constructing of special
tools will be quickly balanced on the profit side when the in-
creased output and the efficiency of the parts produced through
their use are compared with the results under the old methods.
Another advantage to be gained through the use of improved
tools is the almost total elimination of the obtainable results de-
pending upon the degree of skill and intelligence possessed by
the workman ; thus allowing of employing less expensive help
in the manufacture of the required parts.
The above enumerated advantages gained through the use of
modern machines and tools should be so thoroughly recognized
by the executive heads of manufacturing plants that the aim
should be universal to weed out all inferior tools, and allow to
remain nothing but the most efficient machines, tools, and fixtures
in the bauds of- the workman ; so that the mechanic may produce
a greater quantity, or a better quality o^ work, irrespective of
his degree of skill, and without increased exertion — mentally or
physically.
IDEAL TWENTIETH-CENTURY MANUFACTURING.
Ideal twentieth- century manufacturing is attained through
the constant endeavor of shop officials to increase the dividend
33
514 TOOL-MAKING AND'
on each dollar of investment. If an old machine can be replaced
with an improved one which will be capable of producing mure
work, or the same quantity of work with less labor, it should be
installed. Often the installation of a new machine in place of
an obsolete one has saved from fifteen to one hundred per cent,
and over per annum on the investment. Those who doubt this
assertion have only to inquire of the manufacturers of new ma-
chines in order to substantiate my claim.
DEPRECIATION IN MACHINE-SHOP.
The depreciation of a machine-shop that is merely kept in
repair will pile up just as fast as better and improved machines
and tools are installed and used in competing shops. The
amount of depreciation will not be evidenced by the books ; but
it will go on just the same and dividends will be declared out of
the inventory — not out of the earnings. Of course this depre-
ciation can in some cases be continued for some years without
the ultimate end coming in view. But at the best the smash will
only be postponed and the result will be worse. Though this
simple decline in the plant's value may not be considered of
much moment, the increased cost of its product and the inferior
efficiency of the same as compared with that of competing com-
panies will eventually ruin it. While it is not always possible
to replace all or even the greater part of an obsolete equipment
with new machines, it can be done gradually. Keep putting in
better and more efficient tools and machines every year and the
plant will keep its place in the front ranks of prosperous establish-
ments.
CAUSES OF DEPRECIATION IN SHOPS.
Lack of concentration, of specialization, of information, and
too much attention to other duties in the general run of business
usually account for the depreciation of a plant ; as the cost of
installing up-to-date fixtures for the duplicate production of
small repetition parts and the replacing of old machines with im-
proved ones will not ordinarily exceed the extra cost per year of
production by old methods and of running and keeping in repair
the old machines. In fact, there is no excuse for the non-installa-
tion in any shop of a machine which will turn out more and bet-
INTERCHANGEABLE MANUFACTURING. 515
ter work than an old one, as the manufacturers of such machines
are always willing to assume all cost of demonstrating their effi-
ciency and labor-saving qualities.
THE SELECTION OE MACHINES FOE MANUFAC-
TURING PURPOSES.
Again, in the selection of machines for manufacturing pur-
poses, extremes should be avoided. We have to select from the
" universal type, " the " special, " and the "happy medium. " The
"universal " machine unsually lacks efficiency ; and it is difficult
to produce interchangeable machine parts of a high grade in it.
The " special " machine lacks working range; and unless large
quantities of work of the same kind are constantly required the
machine is frequently idle. The "happy medium," then, is the
one for most shops.
UNIVERSAL EQUIPMENT VS. WORKING-RANGE
EQUIPMENT.
In the average machine-shop or manufacturing plant of to-
day important changes frequently occur. In such establishments
the efficiency of the manager lies in his ability to have the shop
ready for such changes — changes which frequently entail the
entire product of the works. Thus a well-informed and prac-
tical manager is able to make changes in the product and at the
same time avoid an excessive depreciation of the shop's value.
The properly equipped machine-shop of to-day has an equip-
ment which is either universal or at least within its working
range and which will at the same time possess the greatest effi-
ciency. Thus the jobbing shop will have a universal equipment ;
while the machine-tool shop will have a working-range equip-
ment. It is to such plants that we owe our manufacturing
supremacy, as they are the ones who compete with and under-
sell foreign manufacturers on their own ground.
CAUSE OF THE GREAT DEVELOPMENT IN MACHINE
TOOLS.
The introducing of innovations and the adaptation of radical
ideas are constantly occurring all along the lines of machine-tool
manufacturing and the production of mechanical apparatus.
516 TOOL-MAKING.
The cause of this wonderful growth in the number of types of
machine tools, and their great capacity for fine work, may be
directly traced to the great improvements in electrical devices,
necessitating numbers of machine tools of improved construction
to produce their complicated parts. This has been the cause of
the great activity in machine-tool improvement and building be-
cause, first, it called for new methods and facilities for manu-
facture.
Another event having an effect on the designing and manu-
facturing of machinery entirely unlooked for at the time of its
inception was the manufacture of the bicycle. This event
brought out the capabilities of the American mechanic as noth-
ing else had ever done. It demonstrated to the world at large
that he and his kind were capable of designing and making
special machinery, tools, fixtures, and devices for economic man-
ufacturing in a manner truly marvellous ; and has led to the in-
stallation of the interchangeable system of manufacture in a
thousand and one shops where it was formerly thought to be
impracticable.
The autocar, automobile, and autocycle are the latest creations
to demand the attention of the designer, tool-maker, and the ma-
chinist. It is in the perfecting and manufacturing of these
twentieth -century marvels of mechanism that they are showing
the world that to them nothing is impossible, and that the in-
genuity and skill which perfected the "dollar watch" will also
prove adecpiate to produce an "automobile for the million."
Forward !
INDEX.
Abrasive, aluminum as an, 500
Accurate jig-making, processes of, 43
jigs, 36
work, milling fixtures for, 141
work on dies, special machines for, 355
Acetylene gas burners, drill jig for, 68
Action of sub-press dies, 466
Advantage gained through the use of improved tools, 513
in the use of special tools, 223
of the end cut in boring tools, 248
Aligning cutter-grinder centres with micrometer, 272
lathe centres with micrometer, 271
Allis-Cbalmers Company, production of perforated metal by, 439
Aluminum, annealing, 497
as an abrasive, 500
base casting, drill jig for, 92
bending and forming dies for, 496
burnishing, 498
cutting dies for, 495
difficulties encountered when working, 492
drawing dies for, 495
engraving and chasing, 498
grades and alloys of, 493
lubricating when working, 494
polishing and finishing, 497
processes and methods for working, 492
pure metal vs. alloys of, 492
secrets in working, 493
sheets, necessary to lubricate before working, 413
shell, die for blanking and drawing, embossing, 410
shells, blanking and drawing, 413
drawing, 496
soldering, 499
spinning, 496
working the metal, 493
American Machinist, extracts from articles in, 121-251
American mechanic, capabilities of, 516
tool-maker, 26
517
518 INDEX.
Angle plate, milling one, 125
Annealing aluminum, 497
and lubricating shells in drawing, 868
Armature disks, 453
machines and dies for, 454
of large diameters, 454
piercing and perforating, 437
segment blanks, 460
notching press, 460
segments, 459
what constitutes, 454
Art goods, dies for stamping and embossing, 468-478
of sheet-metal working in dies, 365
of swaging, 477
Assortment of milling cutters, picking, 232
Attachment for cylindrical perforating, 433
for drilling and tapping in the turret-lathe, 183
for forming pieces from bar in turret-lathe, 163
Automobiles for the million, 516
B
Bag clasps, dies for sheet-metal, 403
Bath for cutters, hot lead, 241
Bearing bracket, drill jig for, 62
milling fixture for, 131
Bending and forming dies for aluminum, 496
nice job in, 416
Bicycle handle-tips, moulds for making, 293
Blades, holding milling-cutter, 229
Blanking dies, cheap, 372
Blanks, fining for drawn shells and cups, 369
Boring bars and reamers, 224
brackets and spindle heads, special machines for, 214
drill jig for power-press bolster, 102
drill-press tables, 220
fixtures, drill-press and, 208
long cast-iron cylinders, 509
rig for drill-press, 212
Bottomless shells, perforating small close patterns in, 435
Bottoms, double seaming of round, 441
seaming burred-edged, 441
Box lid fastening plates, dies for, 389
straps, piercing and spreading dies for, 385
tool for turret-lathe, 169
tools for screw machine, four special, 190
Bracket, bearing, drill jig for, 62
milling fixture for, 131
Brass, bronze, and copper dies, 477
clock wheels, punching, 376
INDEX. 519
Brass parts, reaming holes in, 258
rings, making thin, 305
working tools, and bow to use them, 503
Broaches and broaching, 260
some points about, 265
Broaching, interesting job of, 262
its relation to sheet-metal work, 267
operation of, 261
Bronze, brass, and copper dies, 477
Brown and Sharpe tool-rooms, 39
Burner shells, perforating, 434
Burning cutters, 237
Burnishing aluminum, 498
Burred-edged bottoms, seaming them, 441
Bushing holes, button method for locating, 43
locating and finishing in large jigs, 48
Button method for locating drill bushing holes, 43
C
Cam body, drill jig for multiple, 81
milling machine, special, 337
set of tools for machining, 300
Cams, drill jig for, 78
indexing dial jig for, 109
Casting to be jigged, patterns for, 47
Cast iron impression cylinder, drill jig for, 98
tank for pickling, 509
tinning, 509
Cause of great development in machine tools, 515
Causes of depreciation in machine shops, 514
Centre reamers, 257
Chasing designs in mountings of metal, 472
Cheap blanking dies, 372
jigs, 35
Chief factors in machine manufacturing, 160
Chucks for eccentric straps, 340
for gasoline engine cylinders, 342
for holding pulleys in the turret lathe, 170-172
for turning eccentric rings, 338
two eccentric cams, two-nose, 341
Circular forming tools, 253
notes on, 501
shearing machines, 456
shells, large drawing dies for, 391
Clamp for die and tool-makers' use, 509
Cloth, hollow cutters for punching, 297
Coins, dies for, 468-469
Cold swaging process, 479-482
Collet spring chucks, 310
520 INDEX.
Combination dies for embossed work, 475
Compound dies for parts of telephone transmitter cases, 423
Constructing simple drill jigs, 43
special, devising and, 300
Construction and design of novel drill jigs, 106
of milling machines, improvements in, 122
Copper, bronze, and brass dies, 477
Corkscrews, machine for twisting, 3*27
Cost vs. longevity of the sub-press, 463
Counterbores, 254
Counterboring, 254
large casting in drill-press, facing and, 352
Cup centres, finishing, 222
Curling and wiring processes, 447
deep shells, 452
punch and die, 452
the edges of circular shells, 447
of drawn shells, 450
Cut-off and forming tool, hand for the speed-lathe, 315
Cutters, assortment of milling, 232
burning, 237
classified, milling, 224
degree of hardness in, 241
end mill, 227
gang milling, 235
hardening, 239
and tempering, 239
heating, 240
and hardening large, 243
holding inserted blades of milling, 229
injury in hardening, 241
inserted teeth, 228
interlocking, 235
lead bath for, 241
limits of inaccuracy in, 229
making milling, 235
plunging, 241
regrinding of, 231
sand-blasting, 242
selecting a set of, 232
shell and end milling, 234
side clearance in, 228
speeds and feeds of, 236
spindle surface, milling, 234
standard styles and sizes of, 226
steel for, quality of, 231
suggestions for milling with, 238
test for hardness in, 242
undercut teeth, 226
INDEX. 521
Cutters, use and abuse of milling, 230
warping, 241
Cutting dies for aluminum, 495
edges desirable for boring tools, number of, 246
leather, cloth, and paper with dinking cutters, 397
soft-rubber articles, 506
Cylinders, boring cast-iron, 509
Cylindrical perforating, attachment for, 433
D
Dayton swaging machine, 485
Decorated-sheet metal articles, drawing, 369
Deep hole drilling, 244
shells from sheet metal, drawing, 393
Deflecting device for seaming machines, 443
Degree of hardness in cutters, 241
Depreciation in machine-shops, 514
in shops, causes of, 514
Depth to which shells may be drawn, 368
Design and manufacture of milling cutters, 226
Designer, the, 29
Device for turret-lathe, 190
Devising and constructing special tools, ability to, 300
Dies, and tool-makers' clamp, 509
art goods, 468-478
bending and drawing, 496
brass, 477
clock gears, 376
bronze, 477
cheap blanking, 372
coining, 468-470
compound, for telephone transmitter cases, 423
copper, 477
curling, 452
cutting, for aluminum, 495
drawing for aluminum, 495
for large shells, 391
engraving, 468-478
filing machine for, 361
for box -corner fasteners, 383
bending and forming, 416
blanking and drawing aluminum shells, 413
embossing jewelry, making, 469
forming large sheet-metal articles, 474
jewelry, 468-478
sheet-metal bag clasps, 403
gang sets for eyelets in one operation, 420
hand-finishing vs. machine-finishing of, 356
bobbing, 468-478
522 IXDEX.
Dies, improved piercing, 388
machine for filing, 358
making hobs and sinking embossing, 476
making kink for, 314
milling machines, use of, 357
patterns, modelling intricate, 472
piercing and spreading, 385
punching and curling, 399
without waste in, 380
simper for, 358
shearing, 373
sinking attachment for, 358
with hobs, 468-478
slotter, small, 360
small hole finishing, 374
special machines for accurate work on, 355
sub-press, action of, 466
triple-acting, 410
water or fluid, 474
Difficulties encountered in working aluminum, 492
Disks, armature, piercing and perforating, 437
cutting armature, 453
of large diameters, 454
Double horning and seaming, 443
seaming bottoms on heavy work, 447
machine for irregular articles, 445
of bottoms on special work, 447
irregular can bottoms, 443
round can bottoms, 441
Doubt as to the utility of milling machines, 128
Drawing aluminum shells, 496
and forming decorated sheet-metal articles, 369
annealing and lubricating shells in, 368
a sharp corner under a shoulder, 502
deep shells from sheet metal, 393
dies, for aluminum, 495
way to construct, 370
shell from thin metal, lubricant for, 510
Drawn shells, finding the blanks for, 369
work processes for, 367
Drill bushing holes in large jigs, locating, 48
button method for locating, 43
notes, 252
press and boring fixtures, 208
boring rig, 212
cup centres, finishing, 222
facing and counterboring large castings in, 352
flat tables, boring, 220
job, a, 306
INDEX. 523
Drill-press, milling in the, 311
round tables, machining, 222
Drilling and tapping attachment for turret lathe, 183
deep holes by Pratt and Whitney method, 249
holes in helical surface, 313
jigs, constructing large, 96
simple, 43
for acetylene gas-burners, 68
an aluminum base casting, 92
a spiral line of holes around a cjdinder, 106
bearing bracket, 62
cams, 78
cast-iron impression rollers, 98
dovetailed slide bracket, 101
drilling and countersinking, 76
drilling and hobfacing, 83
drilling and tapping, 115
multiple cam body, 81
nailing-machine cross-head, 96
odd-shaped casings, 70
power-press bolster, 102
round castings in pairs, 74
small accurate work, 89
spider castings, 115
the speed lathe, 66
typewriter bases, 85
indexing dial for small cams, 109
intricate and positive, 81
novel, 118
design and construction, 106
points to remember when making, 104
simple, 42
fourteen-hole, 59
special milling and, 354
their use, simple, 64
with indexing fixtures, 109; 111, 114
job on the planer, 308
set of milling and, 348
small thread dies, jig for, 325
types of simple jigs, 55
Duplicate work in screw machine, method for finishing, 195
E
Eccentric cams, two-nose chucks for machining, 341
rings, chucks for turning, 338
straps, chuck for machining, 340
Effects of work accomplished by swaging, 491
Eli Whitney, 19
524 INDEX.
Embossed work, combination dies for, 474
Embossing, blanking, and drawing, 410
jewelry, making dies for, 469
End cut in boring tools, advantage of, 248
Engraving a hob for sinking medal dies, 468
and chasing aluminum, 498
dies for embossing jewelry, 468-470
machine, special, 334
Etching steel, how to do it, 509
Examples of special uses of height-gauge, 274-278
of micrometer, 271
Expansion reamers, 258
Eyelets, gang punch and die for, 420
Pace milling, fixtures for, 139
Facing and counterboring large castings in drill-press, 352
tools, 254
Factors in machine manufacturing, 160
in the successful use of milling fixtures, 141
involved in designing of drill jigs, 40
Feeding sheet metal to the sub-press, 466
Feeds and speeds for milling cutters, 236
Fibre washers, special tool for cutting out, 329
Filing dies, machines for, 358
machine, 361
Finding the blanks for drawn shells, 369
Finishing cup centres of drill-presses, 222
of dies, hand vs. machine, 356
Fixtures for adjustable stops and spindle racks, jigs and, 320
for milling drill-press tables, 152
Flaking stick, its use, 311
Flat jigs, their use, 32
Follow dies, gang and, 366
Forming irregular pieces from the bar, fixture for, 163
pieces of irregular outline, fixture for, 200
tools, notes on circular, 501
Four special box tools for the screw machine, 190
Fourteen-hole drill jig, 59
' G
Gang and follow dies, 366
die for metal box-lid fastening plates, 389
milling cutters, 235
fixtures for, 138
punch and die for producing eyelets in one operation, 420
Gasoline engine cylinders, chuck for machining, 342
Gauges, 32
Gears, speeds of pulleys and, 508
INDEX. 525
Gelatin moulds, making, 472
Glue for leather and iron, 510
Grades and alloys of aluminum, 493
Great development in machine tools, causes of, 515
Grinder, aligning cutter, centres, 272
Grinding of cutters, 239
rubber, 506
twist drill for cutting section of hole, 505
Grit in rubber, 505
H
Hammering and swaging, 479
Hand cut-off and forming tool for speed lathe, 315
finishing vs. machine finishing of dies, 356
reaming, 259
Hardening and tempering of milling cutters, 239
injury in cutters, 241
test for, 242
Hardness, degree of, in cutters, 241
Hard-soldering, 507
Heating and hardening large cutters, 243
the steel, 240
Heavy work, jigs for, 34
Height-gauge and its use, 274
examples of use of, 274-278
locating holes with, 275
shop use of, 268
Holding cutter blades, 229
devices for jigs, locating and, 41
Hollow cutters for punching leather, cloth, and paper, 397
drill, boring spindles with, 251
Home-made reamers, 259
Horizontal swaging machines, 489
Horning and seaming processes, 440
double seaming and, 443
How to construct a sub-press, 463
drawing dies, 370
I
Ideal twentieth-century manufacturing, 513
Improved piercing die, 388
tools, advantages gained through the use of, 513
Improvement in construction of milling machine, 122
Increasing the size of worn reamers, 260
Indexing dial jig for small cams, 109
milling fixtures, 147
plates, jigs with, 109, 111, 114
Injury in hardening cutters, 241
Inserted teeth, holding, 229
cutters, 228
526 INDEX.
Inside blank -holders, 392
Installation of armature disk punching machinery, 458
of the interchangeable system, 23
Interchangeability, 20
Interchangeable manufacturing, milling machines and, 120
origin of, 19
to-day, 22
Interesting job of broaching, 262
Interlocking cutters, 235
Intricate and positive drill jigs, 81
machinery, modern manufacturing of, 23
Irregular articles, double seaming machine for, 445
Iron and leather, glue for, 510
J
Jeweliiy, dies for making, 468-478
making dies for embossing, 469
Jigs and fixtures, functions of, 30
bodies, handling large, 52
box, 33
cheap, 35
design,, factors involved in, 40
feet, 53
flat, 32
large, 48
making, processes for accurate, 43
work on the plain miller, 50
Jobbing shop work, milling machines and, 120
K
Keeping note-books, 511
sheets straight while perforating, 438
Keyseating in the power-press, 315
Kink, die-making, 314
Knee type of universal milling machines, 123
Lack of knowledge of machine tools, 512
Large drawing dies for circular shells, 391
drilling jigs, 48
Lathe chuck, simple, 312
tool-maker's, 36
Leather and iron, glue for, 510
hollow cutters for punching, 397
Limits of inaccuracy in milling cutters, 229
Locating and finishing drill bushing holes in large jigs, 48
and holding devices for drill jigs, 41
drill bushing holes, button method for, 43
Lock seam, successive stages of, 441
INDEX. 527
Lubricants to use for drawing shells from thin metal, 510
for working aluminum, 494
Lubricating and annealing shells for drawing, 368
M
Machine, Dayton swaging, 487
die filing, 361
finishing vs. hand finishing of dies, 356
for double-seaming irregular bottoms, 445
for engraving poker chips, 334
for filing dies, 358
for twisting corkscrews, 327
manufacturing, chief factor in, 160
reaming of brass parts, 258
with floating reamer, 255
shops, cause of great depreciation in, 514
special cam milling, 337
engraving, 334
tools, 28
cause of the great development in, 515
lack of knowledge of, 512
up-to-the-minute, 512
Machinery, extracts from articles in, 244-481
Machinery for double-seaming round bottoms on cans, 442
Machines and dies used for perforating armature disks, 454
horizontal swaging, 489
rotary swaging, 485
special, for accurate work on dies, 355
Machining a cam, special tools for, 300
a special casting, tools for, 180
drill columns, 156
pulleys, detail drawings of special tools for, 172
round tables, 220
Making and use of simple dies, 371
dies for embossing jewelry, 469
hobs and sinking embossing dies, 476
impressions of elaborate dies, 473
thin threaded brass rings, 305
drill press cup centres, 222
collet spring chucks, 310
Manufacture of accurate sheet-metal parts in the sub-press, 461
of armature disks and segments, 453
segments, large, 459
of milling cutters, design and, 224
Manufacturing, chief factor in machine, 160
ideal twentieth-century, 513
of intricate machinery, 23
origin of interchangeable, 19
purposes, selection of machines for, 515
528 INDEX.
Manufacturing, to-day, ideal interchangeable, 22
Medal dies, engraving a steel hob for sinking, 468
Metal box -corner fasteners, dies for, 383
patterns, 23
Method for finishing duplicate work in the screw machine, 195
for locating drill jib bushings, button, 43
Micrometer calipers, 268
reading them, 270
special uses for, 271
aligning cutter grinder centres with, 272
lathe centres, testing for height of, with, 272
testing lathe centres for alignment, 271
universal use of, 274
used as inside calipers, 273
Milling and drilling jigs, set of special, 348
Milling-cutters, assortment of, 232
burning, 237
classified, 224
degree of hardness in, 241
end, 227
face, 139
gang, 138-235
hardening and tempering, 239
heating, 240
heating and hardening large, 243
holding blades in, 229
injury in hardening, 241
inserted teeth, 228
interlocking, 235
lead bath for heating, 241
limits of inaccuracy in, 229
making, 235
miscellaneous, 152
plunging when hardening, 241
quality of steel to use for, 231
regrinding of, 231
sand-blasting of, 242
selecting a set of, 232
shell and end, 234
side clearance on, 228
speeds and feeds for, 236
spindle surface, 235
standard types and sizes of, 226
test of hardness of, 242
undercut teeth, 226
use and abuse of, 230
warping in hardening, 241
Milling-fixtures, factors in the successful use of, 141
for accurate work, 141
INDEX. 520
Milling-fixtures for bearing bracket, 131
for drill-press tables, 152
for slotting and dovetailing small pieces, 134
for squaring ends of duplicate pieces, 132
indexing, 147
simple, 129
six simple and distinct types of, 129
iMilliug-macliines, compared with other machine tools, 124
doubt as to the utility of, 128
improvements in construction of, 122
in the drill press, 311
in the tool-room, 125
knee type of universal, 133
modern tool-making and, 120
practice, most vital point in, 236
spindle racks, milling in, 323
universal types of, 122
use of die, 357
of universal and plain, 120
utility of, 120
vertical spindle, 127
Modeller's wax, making and using, 473
Modelling intricate die patterns, 472
Most skilled mechanic in the world, 26
Moulds, 279
construction of, 279-299
for bicycle handle-tips, 293
for lead balls, 282
for pencil crayons, 279
for poker-chips, 296
for spherical articles, 298
for telephone receiver pieces, 285
gelatin, for fancy die work, 472
how an accurate set of, was machined in the planer, 288
Movable strippers, 379
Multiple cam body, drill jig for, 81
Multi -spindle drilling and tapping attachment for turret-lathe, 183
N
Necessity to lubricate aluminum before working, 413
IS'ice job of bending and forming, 416
Note-books, how to keep them, 511
Notes on circular forming tools, 501
on drills, 252
Novel drill jigs, 106-118
O
Oberlin Smith's "Press Working of Metals," 267
Operation of broaching, 261
34
530 INDEX.
Origin of interchangeable system, 19
Ornamental articles, dies for forming, 472
Paper, hollow cutters for punching, 397
Patent tool-holders, 507
Patterns for castings to be jigged, 47
Pencil crayons, set of moulds for, 279
Perforated metal, production of, by Allis-Chalmers Company, 439
Perforating and blanking small armature disks, 437
and piercing, 367
attachments for cylindrical, 433
burner shells, 434
flat and cylindrical sheet-metal articles, 433
keeping sheets straight while, 438
large sheets of metal in special designs, 438
small close patterns, 435
taper and crowning shells, 434
Petroleum cans, seaming them, 445
Pickling cast iron, tanks for, 500
Piercing and perforating, 367
and spreading die for box straps, 385
die, improved, 388
Plain forming tools, 253
miller, jig work in, 50
Planer, accurate set of moulds machined in, 288
Plunging heated cutters, 241
Points about broaches and broaching, 265
Poker-chips, set of moulds for, 296
Polishing and finishing aluminum, 497
Polyphase motor, 456
Positive drill jigs, intricate and, 81
Power-press, key-seating in, 315
bolster, drill jig for, 102
Power-presses used for disk punching, 457
Pratt and Whitney method of deep hole drilling, 249
Press, armature disk notching, 460
tools, simplest clas<: of, 366
work, 432
"Press Working of Metals," Oberlin Smith's, 267
Principal use of sub-press, 462
Principle of reproduction, great, 29
Process, cold swaging, 482
Processes and methods for working aluminum, 492
for curling and wiring, 447
for drawn work, 367
horning and seaming, 440
of accurate jig making, 43
INDEX. 531
Producing parts without waste, die for, 380
Progress made in the use of power-presses, 355
Projectiles, reamers for, 257
Pulleys and gears, speeds of, 508
set of tools for machining in one operation, 172
Punching and curling job, 399
brass clock gears, 376
Pure metal vs. alloys of aluminum, 492
Q
Quality of steel to use for cutters, 231
R
Razors, aluminum for sharpening or honing, 500
Reading micrometers, 270
Reamers and reaming, 255
centre, 257
expansion, 258
for babbit metal, 257
for projectiles, 257
hand, 259
home made, 259
increasing the size of, when worn, 260
small parts, machine, 258
holes, 259
square, 258
taper of rose, 257
Reaming holes in the screw machine, taper, 256
in the turret-lathe, 255
in thin disks, 255
in two kinds of metals, 257
taper holes in cast iron, 256
with the floating reamer, 255
Receiver pieces, moulds for telephone, 285
Regrinding of milling cutters, 231
Relation of broaching to sheet-metal work, 267
Reproduction, the great principle of, 29
Rolling of seams, 446
Rose reamers, taper of, 257
Rotary swaging machines, 485
Rough castings in pairs, drilling, 74
Round bodies, machine for double-seaming, 442
drill tables, machining, 222
Rubber, cutting soft, 506
grinding, 506
turning and truing, 505
532 INDEX.
S
Sand-blasting of milling cutters, 242
Screw, cutting coarse-pitch, 804
machine, method for finishing duplicate work in, 195
special tools for, 190
tools and fixtures for speed indicators, 193
Seaming bottoms with burred edges, 441
double horning and, 443
horning process and, 440
petroleum cans, 445
Secrets of working aluminum, 493
Selecting a set of milling cutters, 239
Set of jigs for milling and drilling, 348
of tools for machining a cam, 300
Sextet casting, boring and facing fixture for, 209
Shearing die, 373
Sheet brass blanks, trimming, 313
Sheet metal, depth which may be drawn at one operation, 368
drawing deep shells from, 393
parts, drawing and forming decorated, 369
use of, in place of other materials, 365
work, broaching, its relation to, 267
Shell and end milling cutters, 234
bottomless, perforating, 435
burner, perforating, 434
cylindrical, perforating, 433
Side clearance in milling cutters, 228
Simple dies, making and use of, 371
drill jigs, 42
constructing, 43
drilling jigs and their use, 64
fourteen-hole, 59
types of, 55
lathe chuck, 312
milling fixtures, 129
six distinct types of, 129
slotting fixture, 314
Simplest class of press tools, 366
Sinking embossing dies and drop dies, 468-478
Slotter, small die, 360
Slotting and dovetailing small castings, milling fixture for, 134
Small accurate work, drill jig for, 89
cams, indexing dial jig for, 109
thread dies, jig for drilling, 325
Smith, Oberlin, 267
Soldering aluminum, 499
face plate, a, 310
hard-, 507
INDEX. 533
Some points about broaches and broaching, 265
Special box tools for screw machine, 190
cam milliug machine, 337
casting, tools for machining, 180
chucks for turret-lathe, 170
designs, perforating large sheets in, 439
engraving machine, 334
fixtures in the turret-lathe, use of, 162
job of tool-making, 331
machine for accurate work on dies, 355
for boring drill-press brackets and spindle heads, 214
milling and drilling jigs, 344
tools, advantage in the use of, 223
and fixtures for machining pulleys, 172
for cutting out large fibre washers, 329
for the sc-ew machine, 190
for turret-lathe, 162
uses of micrometer calipers, 271
Speed and feed of milling cutters, 239
indicators, tools and fixtures for, 190
lathe milling, jig for, 318
of pulleys and gears, 508
Spherical moulds, 298
Spindle racks, milling, 322
fixture for, 320
Spring strippers, 379
winding fixture, 309
Square reamers, 258
Squaring holes, die for, 374
the ends of duplicate pieces, milling fixture for, 132
Standard types of milling cutters, 226
Stationary strippers sometimes distort sheets, 379
Step jig, 307
Stick, flaking, 311
Straps, cam for turning eccentric, 340
Sub-press, 461
cost vs. longevity of, 463
dies, action of, 466
feeding the metal to, 466
how to construct, 463
setting and using, 465
use of, 462
utility of, 462
Successful use of milling fixtures, factors in, 141
Swaging, cold, processes of, 479
effects of work accomplished by, 491
machines, horizontal, 489
rotary, 485
the Dayton, 487
534 INDEX.
T
Tanks for pickling cast iron, 509
Taper and crowning shells, perforating, 434
of rose reamers, 257
reaming in the screw machine, 256
Telephone receiver pieces, moulds for, 285
transmitter cases, compound dies for, 423
Templets, 31
Test for hardness of cutters, 242
Testing lathe centres for height with micrometer calipers, 272
The hammer, 479
height-gauge and its use, 274
most skilled mechanic in the world, 26
Tinning cast iron, 509
Tool-holders, patent, 507
Tool-maker's lathe, 36-37
Tool-making, milling machine and modern, 120
unusual job of, 331
Tool-rooms, and their equipment, 36
Brown and Sharpe, 39
milling machines in, 125
Tools for screw machine, special, 190
for speed indicators, screw machine, 193
Trimming sheet-metal blanks, 313
Triple-action die for blanking, drawing, and embossing, 410
Turret-lathe, attachment for forming irregular pieces from the bar, 163
box tool for, 160
multi-spindle drilling and tapping fixture for, 183
set of tools for machining pulleys in, 172
special tools for, 162
tools for machining a special casting in, 180
two special chucks for, 170
use of special device for, 190
special fixtures in, 162
Twentieth-century manufacturing, ideal, 513
Twist-drill, 245
grinding for cutting section of hole, 505
Twisting corkscrews, 327
Two-nose chucks for eccentric cams, 340
Types of very simple milling fixtures, six distinct, 129
very simple drilling jigs, 55
Typewriter bases, drill jig for, 85
U
Undercut teeth, milling cutters with, 226
Universal equipment vs. working-range equipment, 515
milling machines, 122
Up-to-date fixtures and machine tools, 512
INDEX. 535
Up-to-the-minute machines and tools, 512
Use and abuse of milling cutters, 230
and construction of boring fixtures, 208
of brass-working tools, 503
of modeller's wax, making and, 473
of micrometer calipers, 268
of milling fixtures, factor in the successful, 141
machines, 120
of power-presses, progress in, 355
of sheet metal in place of other materials, 365
of special fixtures in the turret-lathe, 162
tools, advantage in the, 223
Utility of milling machines, 120
doubt of, 128
of the sub-press, 462
V
Value of up-to-date fixtures and machine tools, 512
Vertical spindle milling machines, 127
Vital point in milling-machine practice, most, 236
W
Watek or fluid dies, 474
Way to construct a drawing die, 370
to keep note-books of shop practice, 511
Whitney, Eli, 19
Wiring and curling processes, 474
straight work, 448
Working aluminum, 493
Working-range equipment vs. universal equipment, 515
Workman's supplies, 39
Work not to be jigged, 34
Rubber. Belting
*1846 Para" is our finest grade. It indicates exceptional
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^ RUBBER v HOSE ^€
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25 PARK PLACE. NEW YORK
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The Waterbury Farrel Foundry and
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Works and Main ( )ffice j£ fSffiffii?^ N e w Yo r k Office
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Connecticut, U.S.A. * 'Phone, 1069 Cortlandt
C For MODERN WORK use
MATHEWS REAMERS with
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CHARD SPINDLE DRILLS
For Deep Holes
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SPECIAL TOOLS
Ask for Catalog Number Three
Three Rivers Tool Co.
THREE RIVERS ' MICHIGAN
IF YOU ARE INTEREST-
ED OR ENGAGED IN THE
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Advice and Expert Opinion to
Shop Proprietors, Superintendents, General
Managers, Designers, Draughtsmen, Fore-
men, Model Makers, Die Makers,
Blacksmiths, Machinists, Steel
Workers and Tool Makers
Joseph V. Woodworth
Consulting Mechanical Rxpert
Address
279 Cornelia St., Brooklyn, N.Y., U.S.A.
WRITE TO-DAY FOR BOOKLETS
SCIENTIFIC and PRACTICAL BOOKS
PUBLISHED BY
The Norman W. Henley Publishing Co.
132 Nassau Street, New York, V. S. A.
Ej*" Any of these books will be sent prepaid on receipt of price to any address
in the world.
E^ We will send FREE to any address in the world our 114-page Catalogue of
Scientific and Practical Books.
Appleton's Cyclopaedia of Applied Mechanics
This is a dictionary of mechanical engineering and the mechanical arts, fully
describing and illustrating upwards of ten thousand subjects, including agricul-
tural machinery, wood, metal, stone, and leather working; mining, hydraulic,
railway, marine, and military engineering; working in cocton, wool, and paper;
steam, air, and gas engines, and other motors; lighting, heating, and ventilation;
electrical, telegraphic, optical, horological, calculating, and other instruments, etc.
A magnificent set in three volumes, handsomely bound in half morocco, each
volume containing over 900 large octavo pages, with nearly 8,000 engravings,
including diagrammatic and sectional drawings, with full explanatory details.
Price, $12.00.
ASKINSON. Perfumes and Their Preparation. A Comprehensive Treatise
on Perfumery
Containing complete directions for making handkerchief perfumes, smelling
salts, sachets, fumigating pastils; preparations for the care of the skin, the
mouth, the hair; cosmetics, hair dyes, and other toilet articles. 300 pages. 32
illustrations. 8vo. Cloth, $3.00.
BARR. Catechism on the Combustion of Coal and the Prevention of Smoke
A practical treatise for all interested in fuel economy and the suppression of
smoke from stationary steam-boiler furnaces and from locomotives, 85 illustra-
tions. 12mo. 349 pages. Cloth, $1.50.
BLACKALL. Air-Brake Catechism
This book is a complete study of the air-brake equipment, including the latest
devices and inventions used. All parts of the air brake, their troubles and pecu-
liarities, and a practical way to find and remedy them, are explained. This book
contains over 1,500 questions with their answers, and is completely illustrated by
engravings and two large Westinghouse air-brake educational charts, printed in
colors. 312 pages. Handsomely bound in cloth. 18th edition, revised and
enlarged. $2.00.
BLACKALL. New York Air Brake Catechism
This is a complete treatise on the New York Air Brake and Air Signalling
Apparatus, giving a detailed description of all the parts, their operation, troubles,
and the methods of locating and remedying the same. It includes and fully
describes and illustrates the plain triple valve, quick-action triple valve, durlex
pumps, pump governor, brake valves, retaining valves, freight equipment, signal
valve, signal reducing valve, and car discharge valve. 200 pages, fully illus-
trated. $1.25.
BUCHETTI. Engine Tests and Boiler Efficiencies
This work fully describes and illustrates the method of testing the power of
steam engines, turbine and explosive motors. The properties of steam and the
evaporative power of fuels. Combustion of fuel and chimney draft; with formulas
explained or practically computed. 255 pages; 179 illustrations. $3.00.
FOWLER. Locomotive Breakdowns and Their Remedies
This work treats in full all kinds of accidents that are likely to happen to
locomotive engines while on the road. The various parts of the locomotives are
discussed, and every accident that can possibly happen, with the remedy to be
applied, is given.
The various types of compound locomotives are included, so that every engineer
may post himself in regard to emergency work in connection with this class of
engine.
For the railroad man who is anxious to know what to do and how to do it
under all the various circumstances that may arise in the performance of his
duties this book will be an invaluable assistant and guide. 250 pages, fully illus-
trated. $1.50.
FOWLER, Boiler Room Chart
An educational chart showing in isometric perspective the mechanisms belong-
ing in a modern boiler room. The equipment consists of water-tube boilers,
Publications of The Norman W. Henley Publishing Co.
ordinary grates and mechanical stokers, feed-water heaters and pumps. The
various pans of the appliances are shown broken or removed, so that the internal
construction is fully illustrated. Each part is given a reference number, and
these, with the corresponding name, are given in a glossary printed at the sides.
The chart, therefore, serves as a dictionary of the boner-room, the names of more
than two hundred parts being given on the list. 25 cents.
GRIMSHAW. Saw Filing and Management of Saws
A practical handbook on filing, gumming, swaging, hammering, and the brazing
of band saws, the speed, work, and power to run circular saws, etc., etc. Fully
illustrated. Cloth, $1.00.
GRIMSHAW. "Shop Kinks"
This book is entirely different from any other on machine-shop practice. It
is not descriptive of universal or common shop usage, but shows special ways of
doing work better, more cheaply, and more rapidly than usual, as done in fifty
or more leading shops in Europe and America. Some of its over 500 items and
222 illustrations are contributed directly for its pages by eminent constructors;
the rest have been gathered by the author in his thirty years' travel and experi-
ence, fourth edition. Nearly 400 pages. Cloth, $2.50.
GRIMSHAW. Engine Runner's Catechism
Tells how to erect, adjust, and run the principal steam engines in the United
States. Describes the principal features of various special and well-known makes
of engines. Sixth edition. 336 pages. Fully illustrated. Cloth, $2.00.
GRIMSHAW. Steam Engine Catechism
A series of direct practical answers to direct practical questions, mainly
intended for young engineers and for examination questions. Nearly 1,000 ques-
tions with their answers. Fourteenth edition. 413 pages. Fully illustrated.
Cloth, $2.00.
GRIMSHAW. Locomotive Catechism
This is a veritable encyclopaedia of the locomotive, is entirely free from mathe-
matics, and thoroughly up to date. It contains 1,600 questions with their answers.
Twenty-third edition, greatiy enlarged. Nearly 450 pages, over 200 illustrations,
and 12 large folding plates. Bound in maroon cloth, $2.00.
HISCOX. Gas, Gasoline, and Oil Engines
Every user of a gas engine needs this book. Simple, instructive, and right
up to date. The only complete work on this important subject Tells all about
the running and management of gas engines. Full of general information about
the new and popular motive power, its economy and ease of management. Also
chapters on horseless vehicles, electric lighting, marine propulsion, etc. 412 pages.
Large octavo, illustrated with 312 handsome engravings. Twelfth edition, revised
and enlarged. $2.50.
HISCOX. Compressed Air in All Its Applications
Gives the thermodynamics, compression, transmission, expansion, and uses for
power purposes in mining and engineering work; pneumatic motors, shop-tools,
air-blasts for cleaning and painting, air-lifts, pumping of water, acids, and oils;
aeration and purification of water-supply, railway propulsion, pneumatic tube
transmission, refrigeration, and numerous appliances in which compressed air is
a most convenient and economical vehicle for work — with tables of compression,
expansion, and the physical properties of air. Large octavo. 800 pages. 600
illustrations. Price, $5.00.
HISCOX. Horseless Vehicles, Automobiles and Motor Cycles, Operated
by Steam, Hydro-Carbon, Electric, and Pneumatic Motors
The make-up and management of automobile vehicles of all kinds are treated.
A complete list of the automobile and motor manufacturers, with their addresses,
as well as a list of patents issued since 1856 on the automobile industry, are
included. Nineteen chapters. Large 8vo. 316 illustrations. 460 pages. Cloth, $3.00.
HISCOX. Mechanical Appliances, Mechanical Movements and Novelties
of Construction
A complete and supplementary volume to the author's work, "Mechanical
Movements, Powers, and Devices." Contains 1,000 mechanical details and complex
combinations in mechanical construction, which are fully described and illustrated,
including a special and unique chapter explaining the leading conceptions in the
perpetual motion idea existing during the past three centuries. 400 pages. $3.00.
HISCOX. Mechanical Movements, Powers, and Devices
This is a work on illustrated mechanics, mechanical movements, powers, and
devices, covering nearly the whole range of the practical and inventive field, for
the use of mechanics, inventors, engineers, draughtsmen, and all others inter-
ested in any way in mechanics. Large 8vo. Over 400 pages. 1,800 specially
made illustrations, with descriptive text. Tenth edition. $3.00.
Inventor's Manual ; How to Make a Patent Pay
This is a book designed as a guide to inventors in perfecting their inventions,
taking out their patents and disposing of them. 119 pages. Cloth. $1.00.
Publications of The Norman W. Henley Publishing Co.
KRAUSS. Linear Perspective Self-Taught
The underlying principle by which objects may be correctly represented in
perspective is clearly set forth in this book, everything relating to the subject
is shown in suitable diagrams, accompanied by full explanations in the text.
Price, $2.50.
LE VAN. Safety Valves ; Their History, Invention, and Calculation
Illustrated by 69 engravings. 151 pages. $1.50.
MATHOT. Practical Handbook on Gas Engines and Producer Gas Plants
More than one book on gas engines has been written, but not one has thus
far even encroached on the field covered by this handbook. Above all, Mr.
Mathot's work is a practical guide. Recognizing the need of a volume that would
assist the gas-engine user in understanding thoroughly the motor upon which he
depends for power, the author has discussed his subject without the help of any
mathematics and without elaborate theoretical explanations. Every part of the
gas engine is described in detail, tersely, clearly, with a thorough understanding
of the requirements of the mechanic. Helpful suggestions as to the purchase
of an engine, its installation, care, and operation form a most valuable feature
of the work. Fully illustrated. $2.50.
MONTAGUE. Mechanical Drawing for Home Study
This is a practical treatise of instruction arranged for beginners and prepared
especially for home study.
Commencing with simple instruction as to the correct methods employed in
the handling and care of drawing instruments, the author presents a series of
problems in drafting construction that enables the beginner to make substantial
headway from the very first.
Attention has been paid to the matter of making the text explicit, so that
there may be no confusion arising from the improper understanding of the sub-
ject on the part of the learner.
Each chapter of instruction in the principles of drawing is followed by care-
fully arranged lessons to be worked out by the student in the form of drawing
plates, reduced copies of which are shown in full-page illustrations in the text.
500 pages. Fully illustrated.
PARSELL & WEED. Gas Engine Construction
A practical treatise describing the theory and principles of the action of gas
engines of various types, and the design and construction of a half-horse power
gas engine, with illustrations of the work in actual progress, together with dimen-
sioned working drawings, giving clearly the sizes of the various details. Second
edition, revised and enlarged. Twenty-five chapters. Large 8vo. Handsomely
illustrated and bound. 300 pages. $2.50.
REAGAN, JR. Electrical Engineers' and Students' Chart and Hand Book
of the Brush Arc Light System
Illustrated. Bound in cloth, with celluloid chart in pocket. $1.00.
SLOANE. Electricity Simplified
The object of "Electricity Simplified" is to make the subject as plain as pos-
sible and to show what the modern conception of electricity is. 158 pages. Illus-
trated. Tenth edition. $1.00.
SLOANE. How to Become a Successful Electrician
It is the ambition of thousands of young and old to become electrical engineers.
Not everyone is prepared to spend several thousand dollars upon a college course,
even if the three or four years requisite are at their disposal. It is possible to
become an electrical engineer without this sacrifice, and this work is designed to
tell "How to Become a Successful Electrician" without the outlay usually spent
in acquiring the profession. Twelfth edition. 189 pages. Illustrated. Cloth. $1.00.
SLOANE. Arithmetic of Electricity
A practical treatise on electrical calculations of all kinds, reduced to a series
of rules, all of the simplest forms, and involving only ordinary arithmetic; each
rule illustrated by one or more practical problems, with detailed solution of each
one. Sixteenth edition. Illustrated. 138 pages. Cloth. $1.00.
SLOANE. Electrician's Handy Book
An up-to-date work covering the subject of practical electricity in all its
branches, being intended for the everyday working electrician. The latest and
best authority on all branches of applied electricity. Pocket-book size. Hand-
somely bound in leather, with title and edges in gold. 800 pages. 500 illustra-
tions. Price, $3.50.
SLOANE. Electric Toy Making, Dynamo Building, and Electric Motor
Construction
This work treats of the making at hom$ of electrical toys, electrical apparatus,
motors, dynamos, and instruments in general, and is designed to bring within
the reach of young and old the manufacture of genuine and useful electrical
appliances. Fifteenth edition. Fully illustrated. 140 pages. Cloth. $1.00.
Publications of The Norman W. Henley Publishing Co.
SLOANE. Rubber Hand Stamps and the Manipulation of India Rubber
A practical treatise on the manufacture of all kinds of rubber articles. 146
pages. Second edition. Cloth. $1.00.
SLOANE. Liquid Air and the Liquefaction of Gases
Containing the full theory of the subject and giving the entire history of
liquefaction of gases from the earliest times to the present. It shows how liquid
air, like water, is carried hundreds of miles and is handled in open buckets. It
tells what may be expected from it in the near future. 365 pages, with many
illustrations. Handsomely bound in buckram. Second edition. $2.50.
SLOANE. Standard Electrical Dictionary
A practical handbook of reference, containing definitions of about 5,000 distinct
words, terms, and phrases. An entirely new edition, brought up to date and
greatly enlarged. Complete, concise, convenient. 682 pages. 393 illustrations.
Handsomely bound in cloth. Svo. $3.00.
USHER. The Modern Machinist
A practical treatise embracing the most approved methods of modern machine-
shop practice, and the applications of recent improved appliances, tools, and
devices for facilitating, duplicating, and expediting the construction of machines
and their parts. A new book from cover to cover. Fifth edition. 257 engravings.
322 pages. Cloth. $2.50.
VAN DERVOORT. American Lathe Practice
This is a new book from cover to cover, and the only complete American work
on the subject, written by a man who knows not only how work ought to be
done, but who also knows how to do it and how to convey this knowledge to
others. It is strictly up to date in its descriptions and illustrations, which repre-
sent the very latest practice in lathe and boring-mill operations as well as the
construction of and latest developments in the manufacture of these important
classes of machine tools. A large amount of space is devoted to the turret lathe,
its modifications and importance as a manufacturing tool. 320 pages. 200 illus-
trations. $2.00.
VAN DERVOORT. Modern Machine Shop Tools; Their Construction,
Operation, and Manipulation, Including Both Hand and Machine Tools
A new work, treating the subject in a concise and comprehensive manner. A
chapter on gearing and belting, covering the more important cases, also the
transmission of power by shafting, with formulas and examples, is included. This
book is strictly up-to-date and is the most complete, concise, and useful work
ever published on this subject. Containing 552 pages and 673 illustrations. $4.00.
WOOD WORTH. Dies, Their Construction and Use for the Modern Work-
ing of Sheet Metals
A practical work on the designing, constructing, and use of tools, fixtures, and
devices, together with the manner in which they should be used in the power
press for the cheap and rapid production of sheet metal parts and articles. Com-
prising fundamental designs and practical points by which sheet metal parts may
be produced at the minimum of cost to the maximum of output, together with
special reference to the hardening and tempering of press tools and to the classes
of work which may be produced to the best advantage by the use of dies in the
power press. Fourth edition. 400 pages. 500 illustrations. $3.00.
WOODWORTH. Hardening, Tempering, Annealing, and Forging of Steel
A new book containing special directions for the successful hardening and
tempering of all steel tools. Milling cutters, taps, thread dies, reamers, both
solid and shell, hollow mills, punches and dies, and all kinds of sheet-metal
working tools, shear blades, saws, fine cutlery, and metal-cutting tools of all
descriptions, as well as for all implements of steel, both large and small, the sim-
plest and most satisfactory hardening and tempering processes are presented. The
uses to which the leading brands of steel may be adapted are concisely presented,
and their treatment for working under different conditions explained, as are also
the special methods for the hardening and tempering of special brands. 320 pages.
250 illustrations. $2.50.
WOODWORTH. Modern Tool Making and Interchangeable Manufacturing
This book is a complete practical treatise on the art of American tool making
and system of interchangeable manufacturing as carried on to-day in the United
States. In it are described and illustrated all of the different types and classes
of small tools, fixtures, devices, and special appliances which are or should be in
general use in all machine-manufacturing and metal-working establishments
where economy, capacity, and interchangeability in the production of machined
metal parts are imperative.
It is a practical book by an American toolmaker for practical men, written
and illustrated in a manner never before attempted, giving the twentieth century
manufacturing methods and assisting in reducing the expense and increasing the
output and the income. 400 pages. 600 illustrations. $4.00.
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