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 U. S. Department of Agriculture, Forest Service o \#i& 
 
 FOREST PRODUCTS LABORATORY 8 
 
 In cooperation with the University of Wiscon^fc.^ 
 MADISON, WISCONSIN 
 
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 THE USE OF WOOD IN AMERICAN MACHINERY 
 
 By GEORGE C. MORBECK 
 Wood Technologist 
 
 1 UNIV OF FL LIB. 
 
 DOCUMENTS DEFT 
 
 U.S. DEPOSITORY 
 
 J 
 
 Published in 
 
 HARDWOOD RECORD 
 
 July, August, 1936 
 
Digitized by the Internet Archive 
 
 in 2013 
 
 http://archive.org/details/inameriOOunit 
 
;HE USE 0? WOOD IN AMERICAN MACHINERY 
 
 By 
 GEORGE C. MORBSCK 
 Wood technologist 
 
 This "brief description of how and where wood is used for 
 machine parts was prompted by a request from C. I. B, (International 
 Committee on Wood), an European agency interested in wood utilization. 
 The information gathered with respect to American industries should also 
 he of interest to American wood users and to the woodworking and lumber 
 industries in general. In addition it contributes to a subject of 
 current economic interest, namely, the future trend in wood consumption. 
 
 me C the data presented are chiefly of historical interest, 
 since in cc; tain manufacturing industries wood has all but disappeared 
 in current types of machinery. On the other hand, in some machinery 
 lines wood parts have withstood the assaults of encroaching materials 
 to a remarkable degree. The employment of wood for parts of machines 
 of current manufacture is dictated largely by service requirements and 
 cost. There are r.achino -oarts for ?;hich wood is apparently indispensable. 
 For many other parts w"^d is giving satisfactory service at less cost 
 than any material that udght be substituted for it. 
 
 Machinery, for the purpose of this study, is limited to actual 
 operating units in a fairly restricted sense, and does not include other 
 items equally necessary to production, which may be termed accessories 
 or equipment. For example, a paper machine is a highly developed piece 
 of operating machinery. Tanks, vats, and chests are accessories required 
 in paper mailing. In most industries more wood is used in accessories 
 and equipment than in machine parts. No attempt has been made, however , 
 to cover the equipment phase of wood use, except in the pulp and paper 
 industry, where it was found very difficult at times to make a clear-cut 
 distinction between machinery and equipment. 
 
 All industries having machinery that employs wood parts 
 obviously cannot be covered in this brief survey. Many industries not 
 considered probably use more wood for machine parts than some of those 
 covered. The lines of machinery selected for consideration are fairly 
 representative of machinery in general and should afford a good insight 
 into the extent and kinds of wood used for machine parts. 
 
 Agricultural Machinery 
 
 The use of wood in agricultural implements is steadily declin- 
 ing. Apparently it must be proved that wood members in farm equipment 
 
 R1100 
 
arc the equal of or superior to members made of other materials, and 
 where equality of service exists it must he shown that wood can he 
 installed at a lower cost, to make its use possible. 
 
 A study of the current use of wood in agricultural machinery 
 reveals that handles of wood are holding up very well. All types of 
 walking plows, hand corn and cotton drills, and hand and horse-drawn 
 cultivators are equipped almost universally with wood handles. The 
 species used are chiefly oak and ash. Wood handles have advantages over 
 other materials in that they are easily fahricated, can "be readily 
 replaced, and are low in cost. Wood handles also afford a comfortable 
 grip in service regardless of prevailing temperatures, which is an 
 important factor contrihuting to their wide use. 
 
 Plow "beams of wood are apparently on the way out, except for 
 special equipment. Heavy duty plows are made with oak h earns , heavily 
 reinforced with steel. Standard plows are practically all equipped with 
 steel beams. Substitution of steel for wood in standard plows was 
 largely the result of production difficulties, three of which stand out 
 prominently: high loss of stock from warping and checking during season- 
 ing, difficulty of ohtaining a regular and constant supply of h earns , and 
 difficulty of adapting "beams to the various forms required. 
 
 Hitch parts in earlier days were wholly of wood, chiefly oak 
 and hickory. Today practically all horse-drawn farm machines are 
 equipped or can "be suoplied with, metal singletrees and eveners. Poles 
 continue to "be of wood, chiefly southern yellow pine and Douglas fir. 
 
 Grain drills have stood up well against changes in materials 
 of construction. The old standard wood seed "box and wood wheels can still 
 he had in drills, hut the all-steel drill is rapidly replacing the 
 composite type. Implements for preparing soil for crops, in which wood 
 was formerly used in large amounts, now contain practically no wood. 
 Some items still have wood platforms, generally hardv/ood, for weighting 
 with rocks or iron. Wood "bar harrows are occasionally made and disc 
 harrows have hard maple bushings. 
 
 Harvesting and threshing machinery likewisa contain few wood 
 parts. Reel "bars and arms, chiefly of yellow pine; pitmans of hickory 
 or hard maple; conveyor slats of oak, hard maple, or similar hardwoods; 
 occasional elevators, divider hoards, gatherer hoards, and bundle con- 
 veyors, all chiefly of southern yellow pine, constitute the hulk of the 
 few remaining items of wood used in the construction of harvesting and 
 threshing machinery. 
 
 A "bright spot in the agricultural machinery field is the exten- 
 sive use of wood in haying tools. Hay loaders have conveyor slats of 
 maple, oak, or similar hardwoods, and conveyor guides of yellow pine or 
 Douglas fir. Sweep rakes are almost wholly of wood. The long, heavy, 
 square teeth and the framework of the machine arc chiefly southern yellow 
 pine. Hay stackers are also principally wood, most of which is southern 
 yellow pine . 
 
 Hll 00 -2- 
 
The substitution of metal for wood parts of farm machinery, 
 apparently largely a matter of production, often has little to do with 
 the utility of the material dis-olaced. 
 
 Flour Milling Machinery 
 
 Probably no other important industry employs a higher propor- 
 tion of wood in the construction of machinery than flour milling. Many 
 of the machines are almost wholly of wood. Roller mills (grinding 
 machines) are the one notable exception. Flour milling machines are 
 of sturdy construction. Conditions of service of these machines are 
 conducive to long life and replacemnnt is largely due to remodelling of 
 plant or obsolescence. 
 
 The principal items of flour milling machinery are roller 
 mills, sifters, purifiers, bran dusters, and rolls. Malt cleaning and 
 crushing machinery is a closely allied item in which considerable wood 
 is employed. 
 
 Wood used in the construction of flour milling machinery is 
 rather highly standardized as to species and quality of material. Some 
 of the machines are subjected to a continuous oscillating movement in 
 use. All must withstand considerable vibration under operating condi- 
 tions. The frame.:ork of the various machines must therefore be strong 
 and able to withstand constant wracking in service. Wood used in housing 
 machines should be light in weight, and have little "come and go" with 
 normal changes in moisture content thus insuring tight joints at all 
 times. Also the wood should remain in place well with a minimum tend- 
 ency to warp. 
 
 Hard maple is preferred for the heavy framework of all flour 
 mill machines. When hard maple is not available yellow birch is used 
 for machine frames. Posts, top and bottom members, and other frame 
 parts in the larger sizes are approximately 3 ^y 5 inches in cross sec- 
 tion. White ash is extensively used for bracing, door frames, and 
 collector sides. Northern white pine is the standard species for housing, 
 sheathing, conveyors, and similar items where light weight and tightness 
 of construction are essential. Douglas fir is occasionally used for 
 conveyor sides, replacing white pine. Sieve frames of flour sifters are 
 basswood; the cross bars are hard maple, Flour sifters are supported by 
 a series of rock elm rod assemblies. There are usually eight rods in a 
 group and two sets of rods are required for each sifter. 
 
 The encroachment of other materials in flour milling machines 
 has in general not been extensive. Roller mills are of metal except 
 for the housing, which may be either of wood or metal. Few roller mills 
 with metal housing are sold because of their additional cost. Sieves of 
 flour sifters are obtainable with aluminum frames, also at added cost. 
 The interior moving parts of rolls are sometimes of metal, replacing 
 wood. Bran dusters can be had in an all-metal construction. Malt 
 
 R1100 _3_ 
 
cleaning and crushing units are of all-wood and all-steel construction. 
 The increased use of steel in the last mentioned two items is of fairly 
 recent development. 
 
 Textile Machinery 
 
 In the textile industry the heavy framework of looms is grad- 
 ually "being replaced "by steel angle irons. Less wood and more steel 
 is being used in the fabrication of laywoods. Canvas picker stick con- 
 nectors are replacing to some extent hard maple and ash. In some paper- 
 less "beams, low carbon steel is replacing Sitka spruce. Pressed steel 
 sheaves are sometimes installed in the larger looms in place of the hard 
 maple sheaves. In general, however, wood is holding up well in the con- 
 struction of textile machinery. 
 
 Wood in the textile industry is employed for parts where the 
 requirements are usually very exacting. One of the largest loom works 
 reports that in the construction of a wide variety of looms, seven 
 species, namely ash, hard maple, birch, hickory, applewood, yellow 
 poplar, and Sitka spruce, comprise more than 99 percent of the total 
 wood used for machine parts. 
 
 The most important requisite of any wood used for loom parts is 
 its ability to remain straight and true in service. Also of utmost 
 importance is freedom from checking in use. These requirements can be 
 satisfied by selecting straight-grained stock and by proper seasoning. 
 Where large sizes are needed the parts are commonly built up in order 
 to avoid warping and checking in service. In addition to the general 
 properties just named, there are several types of uses of wood in looms 
 that have individual requirements. These requirements are given in the 
 following paragraphs. 
 
 Beams and Rolls 
 
 Beams in this category are cores of large spools upon which warp 
 is wound. The warp is delivered to the loom from the "spool" and only 
 the first winding comes in contact with the wood. Sitka spruce is used 
 exclusively by one large firm for beams. Yellow poplar is employed to 
 some extent by other manufacturers for that purpose. Beams are either 
 solid, in sectors, or built up. Sitka spruce and yellow poplar have 
 sufficient strength for beam use, are light in weight, and machine 
 well with a minimum of splintering, all of which contribute to their 
 high serviceability for beams. 
 
 Rolls are largely guides for the warp and cloth. Aside from 
 stiffness and strength required of a wood for rolls, it must be hard, 
 uniform textured, nonsplintering and wear-resisting. A smooth surface 
 is essential at all times. The wearing surface of this type of roll 
 is exclusively hard maple. Small rolls are solid; large rolls are 
 
 Ell 00 -h- 
 
"built up with yellow poplar ends and Sitka spruce centers. Cloth 
 guide-rolls of certain types are Sitka spruce, particularly the large 
 covered rolls of "built-up material. Rolls which receive the finished 
 product are also largely of spruce. 
 
 Framework, Connectors, and Beams for 
 Attachment of Working Farts 
 
 The added requirements for most of the wood parts in framework, 
 connectors, and attachment "beams are high strength and hardness, good 
 wearing qualities, and high shock resistance. Apparently white ash 
 satisfies these requirements very well, since, except for a small amount 
 of hard maple, it is the wood most used for the purpose. 
 
 Shuttle Racks, Runs, and Shuttle Tops 
 
 Wood for shuttle racks, runs, and shuttle tops must "be hard 
 and wear resisting, and must remain smooth in service. By far the most 
 extensively used wood for such purposes is apple. Dogwood is used in 
 smaller amounts. For the most exacting parts Turkish and West Indian 
 "boxwood are employed. 
 
 Picker Sticks and Connie tors 
 
 The requirements of a wood for picker sticks are most exacting. 
 The ideal wood should be light in weight, very strong, tough, and resilient, 
 Hickory conforms most nearly to the requirements for picker sticks, and 
 hence is universally used for that purpose. Picker stick connectors are 
 of hard maple and ash because of their high strength and general service- 
 ability. 
 
 Sheaves, Bearings, and Similar Items 
 
 Sheaves, "bearings, and similar items are of hard maple. The 
 hardness and ability of maple to wear smooth in service adapts it well to 
 such uses. When employed for bearings and bushings, maple is made self- 
 lubricating by Impregnating with oil. The extensive use of oilless bearings 
 in the textile industry is due to the fact that they reduce the hazard 
 of soiling cloth-making materials. 
 
 Dobby Bars and Cylinders 
 
 Bars and cylinders of dobby looms are constructed chiefly 
 of birch and hard maple. Both uses require a hard, strong wood that 
 wears smooth in service and is not splintery in boring. Birch, according 
 to one large manufacturer, splinters less than hard maple and is there- 
 fore preferred. 
 
 R1100 -5- 
 
Dairy Products Machinery 
 
 Tfood in machinery for making dairy products is confined largely 
 to churns, cheese vats, and cheese presses. Smaller items, such as hand 
 "butter workers, "butter printer "boxes, ladles, and packers, are also chiefly 
 of wood. 
 
 The requirements of wood in dairy products machinery are quite 
 exacting. Of first importance is the matter of freedom from imparting 
 objectionable odor or taste to the manufactured product. The wood should 
 also be strong, stable in service, and have low shrinking and swelling 
 in use. This requirement is attained by employing only edge-grained 
 material. High decay resistance is also essential. Other factors being 
 equal, the cost of lumber for items requiring stock of large sizes limits 
 to some extent the species used* 
 
 Commercial butter churns are essentially closed tanks of various 
 sizes to suit individual requirements. The cylinders and heads of churns 
 made by one of the largest manufacturers of commercial dairy products 
 equipment are of clear heart vertical grain Douglas fir. The staves are 
 of various thicknesses, ranging usually from 1-1/2 to 2 inches when 
 finished. Douglas fir stave stock is purchased rough, and is surfaced, 
 tongue and grooved, and run to the proper curvature in one operation. The 
 width of staves is uniform for churns of all sizes, nominally ^ inches. 
 Churn heads are of stock 10 to 12 inches wide. Churn shelves are also 
 of clear heart vertical grain Douglas fir. Butter rolls are redwood. 
 Each roll is made from a 7 ^>7 7~i nc h or a 10 ly 10-inch redwood timber. 
 The stock is practically green when used. Churn doors are of 1-inch 
 redwood, Douglas fir, or cypress, usually in one piece, up to 13 inches 
 in width. Vertical grain stock is preferred. 
 
 Cheese vat frames are of vertical grain Douglas fir of the 
 same quality as for churns. The stock is wide and occasionally in the 
 larger vats 2-1/2 inches thick. Douglas fir is also used in large 
 sizes for cheese press frames. Redwood is occasionally used for cheese 
 vats and presses on special order. 
 
 Hand butter workers are hard maple. Butter print "boxes are 
 heart yellow poplar. The sides are of one piece IS inches wide. Ladles 
 and packers are usually hard maple. 
 
 There has been no substitution of other materials for wood 
 in commercial churns. The wood used, however, has changed with time, 
 due to difficulties in obtaining suitable material or to high cost. 
 Early churns were commonly of yellow poplar and cypress with yellow 
 poplar rolls. Hard maple was also used for rolls. Douglas fir and red- 
 wood, the species currently used for cylinders, shelves, and rolls, are 
 apparently satisfactory in use and are readily available in the sizes, 
 types , and grades required. 
 
 R1100 
 
Cheese vats and presses can "be had of all-metal construction. 
 The use of metal vats is increasing. 
 
 3 oard Drop Hammers 
 
 Board drop hammers are in common use in the production of 
 certain types of forgings* The essentials of such equipment are the 
 ram to which the hoard is attached and the rolls which, pressing against 
 the hoard, lift the ram to the height desired for dropping. Clamps are 
 sometimes used for gripping the hoard instead of rolls. Hammer hoards 
 are invar iahly of hard maple. Many other species have "been tried, hut 
 none seems to he as satisfactory as maple. Boards range in thickness 
 from 1-l/U to 1-3/A inches, in width from 2-1/2 to 16 inches, and in 
 length prohahly from 6 to 12 feet. The most commonly used finished hoard 
 sizes appear to he 1-3/32 to 1-1/2 inches thick, 5 to 6 inches wide, and 
 8-1/2 feet long. Boards over 8 inches wide are "built up of two or more 
 narrow pieces. 
 
 Hammer hoards are subjected to hard usage. The life of a hoard 
 in service may he only a few minutes if serious hidden defects are present, 
 or 3^0 or more operating hours under favorable operating conditions. The 
 average life of hammer hoards in service is prohahly somewhere "between 50 
 and 100 operating hours. 
 
 Hard maple for hammer hoards must he straight grained, flat, 
 sound, and dense. The wood must also he thoroughly seasoned. Failure 
 of the wood in hammer hoards is due largely to crushing of the hoard 
 where gripped hy clamps or where the rolls start in raising the ram. 
 The shock sustained hy the hoard at moment of impact is likely responsible 
 for failures through splitting. Boards seldom if ever fail due to the 
 load "being lifted. 
 
 The volume of maple used for hammer hoards cannot readily he 
 estimated. Manufacturers of hammers furnish some hoards, hut the hulk 
 of the stock is supplied hy local dealers. There is at present no sub- 
 stitute material replacing hard maple for hammer hoards as far as can he 
 determined. 
 
 Commercial Laundry Machines 
 
 Wood in laundry machinery is confined chiefly to washers. The 
 conditions which have to he met in a material for washers involve largely 
 corrosion in contact with chemicals employed in washing processes, and 
 contamination or staining of the clothes. Wood resists chemical action 
 and contains no substances injurious to fahrics. 
 
 Commercial washers consist essentially of two parts, the shell 
 or stationary tuh, and the interior cylinder. The shell in the "best 
 
 H1100 -7- 
 
grades of washers usually has heart cypress staves and heads. Other 
 soft?/oods having high decay resistance are probably also suitable for 
 shells in the better grades of washers. Lower priced washers have tubs 
 of Douglas fir. Both staves and heads are usually of 2-inch material. 
 Heart cypress and Douglas fir have sufficient strength for tub use, 
 hold fastenings well, resist action of chemicals, and arc resistant to 
 decay. 
 
 lasher cylinders are commonly of heart longleaf pine. This 
 species is preferred for cylinder parts because of its high resistance 
 to wear under action of chemicals employed in washing. Cylinders of 
 longleaf pine and similar woods are strong and rigid and hold up well 
 in service. In the better grades of washers, heads of cylinders are of 
 3-inch stock. Staves are generally 2 inches thick. 
 
 Hard maple lifting ribs are the rule. Hard maple has the high 
 wearing and nonsplintering qualities required in a wood for rib use. 
 Doors and door ribs are commonly of the same species as the staves. 
 
 Current types of commercial washers show some replacement of 
 wood by other materials. Washers with brass cylinder partitions and 
 doors and with monel metal lifting ribs are available in the higher 
 priced lines. Galvanized iron doors are replacing wood doors in the 
 cheaper grades of product. 
 
 P ulp and Paper Machinery 
 
 The use of wood in the construction of pulp and paper plants 
 is declining with each new mill installation, Wood when employed is 
 confined to structural units, such as conveyors, chip bins, and other 
 component parts of the building and in more or less nonoperating items , 
 which to differentiate them from operating machinery, may be classed 
 as equipment. In this category are storage tanks, vats, screen boxes, 
 bins, pipes, tubs, and chests. 
 
 It is obviously difficult in many cases to separate equipment 
 from the machinery it serves. Since the bulk of wood used in pulp and 
 paper manufacturing processes is employed in items defined as equipment, 
 it may be well to cover briefly the use of wood in that classification. 
 
 Species used for containers of liquids and pulp mixtures are 
 the regular tank and vat woods, principally cypress, redwood, Douglas fir 
 and southern 2^ellow pine, including longleaf, generally of tank grade. 
 Prom the standpoint of service other species can be substituted in some 
 types of tanks and vats; the foregoing woods, however, are readily avail- 
 able in stock sizes, which is a considerable advantage when purchasing 
 tank lumber. The species employed for tank, vat, tub, or chest depends 
 on the type of use to which the container is put. Containers of southern 
 yellow pine and Douglas fir are commonly employed for storing chemicals 
 in which chemical action on the wood is the principal cause of failure. 
 
 H1100 _8_ 
 

Stock ready for the paper mill, because of frequent washings is free of 
 injurious chemicals. Deterioration of various wood containers used in 
 the latter stages of paperraaking is therefore due largely to decay. 
 Where long life is desired of such containers, heart cypress is commonly 
 employed in their construction. Heart redwood is probably equally suit- 
 able. Quite commonly, however , little attention is paid to species for 
 tank and vat construction as between the various species mentioned. 
 Douglas fir and southern yellow pine are less expensive than redwood 
 and cypress, and that consideration is sometimes the determining factor. 
 
 Pipes carrying stock or water are often of wood. Douglas fir 
 and redwood are commonly used for stave pipe. Wood pipe is preferred 
 by many to pipe of other materials because of its low tendency to "slime," 
 and its relatively low cost. 
 
 Wood in pulp and paper equipment is rapidly being displaced by 
 metal, concrete, rubber, and other materials in new installations and 
 also often in replacements. Tanks, vats, sieve boxes, and similar items 
 are principally affected. These items will probably continue to have 
 certain wood parts, such as agitation arms, which are of hardwood — 
 chiefly hard maple, oak, and ash; cylinder fins for elevating pulps in 
 deckers; some wood couch rolls in wet machines of a variety of species, 
 such as hard maple, black gum, cypress , yellow poplar, and yellow pine; 
 and filler strips between beater bars, chiefly of hard maple and oak. 
 The total incidental wood employed in modern equipment for making paper 
 is small, with little apparent chance of future increase. 
 
 A still smaller volume of wood is used in pulp and papermaking 
 machines, especially in machinery of the latest designs. The machine 
 that probably uses the largest amount of wood is the "Jordan," which 
 consists essentially of an outer shell with a cone-shaped plug. The 
 filler strips between the metal bars of both shell and plug are hardwood, 
 chiefly red oak and sugar maple. 
 
 "Save-alls" at the front end of paper machines are often of 
 wood construction. Cypress or some other decay-resistant softwood of 
 tank stock grade is commonly employed for this item. The "shock ab- 
 sorber" attached to a shaker is of wood, usually hard maple. Suction 
 box covers are hard maple, or some other long, even-wearing species. 
 Recent paper machine installations have suction box covers of bakelite. 
 
 Press rolls of wood are obsolete.. Pelt rolls are of yellow 
 poplar, basswood, or some other soft fine-textured species. New materials 
 for rolls include rubber metal, various compositions, and granite. 
 
 Wo od Bea r ings and Bushings 
 
 Bearings and bushings of wood have been used in machine con- 
 struction for many years. Although developments in machine design and 
 materials have eliminated wood bearings in many types of equipment there 
 
 B1100 _q_ 
 
are still certain machines in which nothing appears to "be more suitable 
 for "bearing use than woqd. Improvements in wood "bearings and "bushings, 
 in recent years have increased their usefulness considerably, and new 
 uses for those items have teen developed. Practically all wood bearings 
 and bushings are now impregnated with lubricating material. The result 
 is a bearing that needs no oil during its useful life. 
 
 Oilless bearings and bushings have four principal uses for 
 which they are well adapted: for use in locations difficult of access; 
 where oil or other lubricants would soil or damage the product being 
 made; where use conditions require occasional or frequent removal of 
 bearings; and where use of ordinary lubricants is impractical or im- 
 possible. 
 
 Probably the most general use of wood bearings and bushings 
 is in textile machinery, where danger of damage through soiling of 
 fabrics in the various processes of manufacture must be kept to a mini- 
 mum. For similar reasons wood bearings are extensively used in washing 
 machines and wringers. Certain types of agricultural machinery are 
 equipped with wood bearings and bushings, notably disc harrows. When 
 worn out or broken in such use they can be quickly and cheaply replaced. 
 Wood bearings are emplojred in equipment that is constantly submerged in 
 water or other liquids in service. The use of ordinary lubricants under 
 such conditions is obviously impossible. In addition to the foregoing 
 uses, wood bearings and bushings are employed in flour machinery, shoe 
 machinery, paper folding and envelop equipment, cream separators, cash 
 carriers, vacuum cleaners, wells and pulps , scientific instruments, 
 hydraulic equipment, and stern bearings for ships. For the last named 
 two purposes lignum vitae is the principal wood used. 
 
 Practically all wood bearings and bushings are of hard maple. 
 The type of maple employed is usually northern grown clear sap stock. 
 Por some uses beech is satisfactory. 
 
 There are a number of firms making wood bushings and bearings 
 though the market for them so far as number of outlets is concerned is 
 probably decreasing. In equipment that employs large quantities of wood 
 bushings and bearings, however, such as agricultural implements, textile 
 andlaundry machinery, the volume of wood consumed is still large and may 
 actually be increasing. Because of the nature of the industry no figures 
 on consumption of wood for bearings and bushings are available. 
 
 Wood Pulleys 
 
 The use of wood for pulleys probably dates from the first use 
 of belts or similar contrivances for transmitting power. With the pass- 
 ing 2'ears , improved design and better construction have combined to keep 
 wood pulleys on the market in competition with those of metal and other 
 materials of which there are countless designs, kinds, and types. The 
 
 R1100 -10- 
 

production of wood pulleys has undoubtedly fallen off in recent years, 
 but one company of the half dozen or so that make wood pulleys still 
 uses almost half a million feet of lumber annually in their construction. 
 
 Wood pulleys are of two general types — split pulleys and 
 solid pulleys. Split pulleys are of two identical parts each consisting 
 of a wood face made up of narrow glued members, and wood arms, one, 
 two, or more depending on the size or design of the pulley. The faces 
 or rims of wood pulleys are of "basswood, sap gum, tupelo , and probably 
 other hardwood species in small amounts. Pulley arms are commonly of 
 hard maple and "beech. Bushings are hard maple or sometimes "beech. 
 Solid pulleys are commonly hard maple. 
 
 Manufacturers of wood pulleys assert that lightness of 
 weight and high strength combined with high coefficient of friction 
 make it possible to run such pulleys safely at higher speeds than 
 pulleys of other types of construction. 
 
 R1100 -11- 
 
AORI CULTURAL MACHINERY 
 
 The aubatltutlon of metal for wood 
 parte of agricultural lmplemente has, 
 during the past two decades, reduced the 
 volume of wood per unit of production 
 about one-half. One line of equipment 
 that haa withstood the attack of steel 
 la haying tools. At the right le a 
 swing rake. Standard equipment of this 
 type Is almost wholly of wood, chiefly 
 eouthern pine. 
 
 The grain drills also shown at the 
 right represent a class of equipment In 
 the construction of which wood la grad- 
 ually being replaced by metal. The 
 drill at the top has a wood seed box and 
 wood wheels. Below It Is a drill made 
 wholly of metal. 
 
 Below la a cut Illustrating a 1914 
 model corn sheller almost wholly of wood. 
 The 1932 model shown below It haa changed 
 little In appearance, except that no wood 
 Is used In Its construction. 
 
 The old reliable oak plow beam haa 
 been relegated to special Item olass. 
 Handles of walking plows, cultivators, 
 and similar Items, however, are still 
 universally of wood, principally oak and 
 ash. 
 
 Sjt-e* **■«*»* affc4VfcWi.Sk 
 
 ZH 33368 T 
 
FLOUR MILLING MACHINES 
 
 Wood occupies a commanding position 
 •a a material In the construction of all 
 types of maohlnery used In flour manu- 
 facture. A glance at the Items Illus- 
 trated Indicates the extent to which wood 
 Is employed. The heavy framework of all 
 the machines shown, except the roller 
 mill, is of clear hard maple. When the 
 proper type of maple la not readily 
 available, yellow birch is sometimes used 
 for frames. Smaller items of framework, 
 braoing, door stiles and rails, and hop- 
 per aides are ash. Housing and panels 
 are northern white pine. Flour sifters 
 are supported by a aeries of rock elm 
 rods one Inch in diameter. Sifter 
 sieves nave basswood aides and oroas 
 bars of hard maple. 
 
 Wood is especially well adapted for 
 flour milling machinery. The heavy wood 
 construction of the various machines re- 
 sists very well wracking and vibration 
 which are the primary oauses of their de- 
 terioration. The clean, sanitary appear- 
 anoe of wood is an important asset in its 
 use In flour production. 
 
 
 Zli 28366 F 
 
TBXTII2 MACHTKBRT 
 
 Wood Is an Important ltsm In the construction of 
 loom* and other textile machines. For many iioMnt 
 parts no satisfactory substitute for that material has 
 been found, aside from the more general properties re- 
 quired of all wood employed, special requirements for 
 Individual machine parte are very exaotlng, and limit 
 the woods used to a very few species. Hard maple, yel- 
 low birch, hickory, ash, applewood, yellow poplar, and 
 Sitka spruce comprise the bulk of wood used in looms. 
 
 The heavy wood framework in the loom shown below 
 is ash. Applewood is extensively used for circular 
 shuttle oovers. The shuttle assembly is the piano 
 key- like arrangement running the length of the loom. 
 It is supported by aah beams. The beam uprights in the 
 background are also ash. 
 
 The dobby loom above 
 has cylinders of hard ma- 
 ple. The bars passing 
 over the cylinders common- 
 ly are yellow birch. Hard 
 .pie is also used for cyl- 
 inder bars. 
 
 At the right is a typ- 
 ical silk loom. The rolls 
 in the foreground are Sitka 
 spruce. The breast board 
 tray above the rolls is yel. 
 low poplar. Sheaves shown 
 at the top are hard maple. 
 The upright piece at the 
 lower right is the picker 
 stick which is invariably 
 of hickory. The horizontal 
 picker stlok connector la 
 
 Ti4 
 
 'i " : 
 
 ZM 28367 F 
 

 COMMERCIAL DAIRY MACHHBRT 
 
 Wood retains its supremaoy In many of too larger Item* 
 of maohinery In the dairy products field. lo other material 
 haa replaced wood in butter ohuras. The ohura cylinder la 
 commonly of clear edge-grain Douglas fir heartwood. Churn 
 doora formerly of oypress are now largely edge-grain redwood. 
 Shelves attached to the aide* of the churn are usually Doug- 
 las fir. The large butter rolls are redwood. The Illustra- 
 tion at the right shows the arrangement and extent of use of 
 wood In commercial churns. 
 
 Cheese vats and oheese presses Illustrated below are of 
 Douglas fir construction. All-steel vats and presses are 
 available at considerably greater oost. 
 
 The sides of the printer 
 are clear heart yellow poplar 
 In one pleoe. 
 
 IMFLZMB1JTS BHFLOSED IH BOTTBR mATCHO AHD PACKIliO 
 
 All of the Items Illustrated above are of olear hard ma- 
 ple. Beeoh and birch are also used for ladles and paddle a 
 employed In butter making. 
 
 1U 28371 T 
 
{ 
 
— tv _ 
 
 COMMERCIAL POWER WASHER 
 
 Wood oontlnuea to be used in considerable quanti- 
 ties in commercial laundry machines. The requirements 
 of construction materials are exacting. They must 
 stand up under the action of chemicals and Impart noth- 
 ing that will damage clothes in the washing process. 
 ■o low-priced material is as serviceable as wood In 
 power washers. The shell of the washer shown above Is 
 Douglas fir. Cypress is used for the more expensive 
 •hells. 
 
 The interior cylinder and partitions are usually 
 of longleaf pine. Lifting ribs (not shown) are common- 
 ly bard maple. 
 
 BOARD DROP 
 
 The type of forging 
 shown above employs a board for 
 lifting the rsja into position 
 for the drop. Hothlag but clear 
 straight-grained hard maple la 
 used for hammer boards. High re- 
 sistance to side compression and 
 ability to absorb shook are es- 
 sential in a wood for that uae. 
 The average life of hammer boarda 
 ranges from 60 to 100 working 
 hours. 
 
 
 PULP AND PAPER MACHINERY 
 
 Wood in machinery employed In the 
 paper Industry is on the decrease. Tanks, 
 tubs, vats, sieves, and similar equipment 
 formerly almost wholly of wood are in new 
 Installations often of steel, concrete, 
 and other materials. There la little wood 
 used in operating machinery. The illus- 
 tration at the left shows wood bars in the 
 tapered plug of a "Jordan." The station- 
 ary shell in which the plug revolves is 
 similarly equipped with wood fillers. The 
 wood used Is obiefly oak. 
 
 The eccentric sore en shown above and 
 similar screens have sides, ends, and 
 other parts of wood. The speoies employed 
 la eommonly cypress. Other softwoods hav- 
 ing nigh deoay resistance are also suit- 
 able for screen use. 
 
 1M 28370 F 
 
BBARIVOS AND BOSBXJM 
 
 Wood bearings and buablnga were quit* 
 commonly employed In early factory and shop 
 equipment. Por certain uses they have main- 
 tained themselves In spit* of great advances 
 In engineering praotlce In reoent years. 
 Practically all wood bearings and bushings 
 are Impregnated with oils, waxes, paraffin, 
 or similar materials to provide ollless lu- 
 brication. Such lubrication Is essential In 
 machines where ordinary lubricants will dam- 
 age goods In the process of manufacture, for 
 example, textile products. Wood bushings and 
 bearings are employed In locations difficult 
 of aooass. They are also extensively employed 
 In agricultural machinery, notably dlao har- 
 rows, because of their easy replacement and 
 low cost. 
 
 Wood bushings and bearings are chiefly 
 aapwood of hard maple. That wood la strong, 
 fine -textured, wears well, and Impregnates 
 readily. 
 
 Wood Ittishintfs 
 
 WOOD SPLIT PULLETS 
 
 Pulleys of wood were formerly in quite general use In 
 mills and factories and are still employed to a considerable 
 extent In some Industries. The chief advantages claimed for 
 wood split pulleys are their lightness, ability to run at 
 high speeds without danger of breaking, and non-slipping 
 property. Wood pulleys can readily be made In any size and 
 type. They are also relatively Inexpensive. 
 
 The faces of wood-split pulleys are built up of parallel 
 curved strips of baaswood, sap gum tupelo, and probably other 
 hardwoods. The arms 
 are of hard maple or 
 occasionally beech. 
 Wood pulleys are often 
 equipped with hard ma- 
 ple bushings. 
 
 211 23369 F 
 
 s 
 
 Block pulleys 
 are commonly 
 of hard maple. 
 
UNIVERSITY OF FLORIDA 
 
 3 1262 08928 0209