The Iron Age 1943-08-12: Vol 152 Iss 7

praty GUST 12, 1943 4 One five Fairbanks-Morse Scales with Printomatics the Minnequa Plant the Colorado Fuel Iron Scales equipped with Printomatics take the responsibility for accurate weighing from men, make automatic, and furnish printed record. Fairbanks, Morse Co., 600 South BUY WAR BONDS Michigan Avenue, Chicago, Illinois. y Hydrogen Brazing Furnaces are the modern plant Carbide Fabricators, Inc. who make large numbers nothing but tipped tools. They say the fine brazing job, and fast production rate (which cannot expressed figures). The hydrogen consumption controlled and HOS Philadelphia under act March 1879. FIXTURES SPARK PLUG ELECTRODE WIRE SPECIAL ALLOYS NICKEL PROTECTION TUBES THE IRON AGE, published every Thursday the CHILTON CO. (INC.). yearly North economical. The furnace well powered, work—which pushed through manually. The Hoskins Brazing Furnaces are being widely used war production. For the full story, write Hoskins Co., (8), Michigan. Entered second class matter November 1932, the Post Office America and South America, Foreign $15. Vol. 152, No. 4 | VAN DEVENTER President and Editor BAUR Vice-President General Manager This AGE ° ° Editorial and Advertising Offices East 42nd St., New York ¥., Vol. 152, No. August 12, 1943 Bour, Typography and Layout. Editorial Regional Business Managers New York New York 100 East 42nd St. 100 East 42nd Woodward Ave. Box Heavy Gun Tubes from Seamless Tubing Ave. Mechanical Ingoting Aluminum and Magnesium CHILTON COMPANY New Metal Etching Method (Incorporated) : ° ° Executive Offices Chestnut and Sts., Features Philadelphia 39, Pa., U.S.A. GEORGE GRIFFITHS Vice-President JULIAN CHASE THOMAS KANE News and Markets Member, Audit Bureau Lack Workers Hampers Plane Plants 113 Manpower Now No. Railroad Problem. Member, Business Machine Tcol News 156 Non-Ferrous Metals News and Non-Ferrous Metals Prices; Scrap Prices 159 Iron and Steel Scrap News and Prices 160 Finished Iron and Steel Prices Steel and Warehouse 164 Indexed the Arts Stainless Steel, Tool Steel Prices 165 North America, South America and Semi-Finished Iron and Steel Single Copy, cents. Annual Number, Pig Iron Prices 168 ° ° | 1 | | q T. Office RYERSON IRON AGE, August 1943 Structural Steels ... Stock Ryerson Your nearby Ryerson plant has good stock all standard sizes beams, channels, angles, tees and zees available any desired length with adequate facilities for cutting, punching and otherwise preparing the steel your exact specifications. Ryerson also carries large stocks bars, plates, sheets, tubes, stainless, alloys and hundred and one other steel products. Ten plants are strate- gically located for nation-wide Steel-Service. Our engineers and metallur- gists will gladly help you any probem selection, supply, application fabrication. Whatever your steel needs call RYERSON first! Joseph Ryerson Son, Inc. Plants at: Chicago, Milwaukee, St. Louis, Detroit, Cincinnati, Cleveland, Buffalo, Boston, Philadelphia, Jersey City. Mana News, Techn Regic q IRON ESTABLISHED 1855 VAN DEVENTER President and Editor BAUR Vice-President and General Manager DIX Manager, Reader Service ° Managing Editor....... LIPPERT News, Markets Editor...D. JAMES ° ° ° Associate Editors MacDONALD BARMASEL BUTZNER Editorial Assistants SCHIEN WILLIAMS Regional News and Technical Editors CAMPBELL Pittsburgh 428 Park PHAIR Chicago 1134 Otis Bidg. MOFFETT Washington National Press BROWNE Washington National Press Bidg. LLOYD Cleveland 1016 Guardian BRAMS Detroit 7310 Woodward Ave. OSGOOD MURDOCK San Francisco St. Editorial Correspondents ROBERT Cincinnati PENLEY Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE Birmingham ROY Louis JAMES DOUGLAS Seattle Only Bureaucrat Loves Bureaucrat ORDS come have meanings peoples’ minds which may quite different from their dictionary definitions. And the same word may convey very different connotations various persons. Thus the word “law” means one thing thief and something quite dif- ferent lawyer. have never known anyone, however, outside the bureau- cratic circle itself, who had kind word for bureaucracy. true that Harold Ickes said several good words for during his recent speech before the Sales Executives’ Club New York, but not think that made many converts. most who are the receiving end, bureaucracy means something avoided much possible. means the issuance rules and regulations, particularly don’ts. means something similar those “keep off the grass” signs our public parks which are phrased without “please” front them. have put with certain amount bureaucracy even peace times because one seems have found method running democracy without it. And war time many more rules and regula- tions are necessary that bureaus and boards and commissions, practically all which are headed appointees, have multiplied enormously. The more bureaus, boards and commissions have, the further get away from democracy for the simple reason that our rules and regulations then, instead being issued elected representatives who are responsible the public, are issued appointees who are responsi- ble their appointer. Probably over per cent the rules which govern today come from this source. The danger this not the present size state bureaucracy, most which may necessary for war. lies the fact that may get used and tolerate unnecessary amount after the war. And that would injurious every class Americans except one class, the bureaucrats. Under the urge war necessity, lines authority which not stem from the electorate are being established almost every field effort, lines which tend reduce individualism minimum realizes the necessity breaking these lines super-government after the war least many them are possible. Labor, management and the American consumer have equal stakes doing this and face equal dangers their freedom not done. The bureaucratic octopus respecter persons and its tentacles reach and grasp blindly. The well-being business, labor and our consumers de- pendent upon our seeing that the American environment after the war will such permit the maximum exercise individualism the part every one that consistent with the rights his fellow men. | ] ul | | | | | q | : | | { Three operators pierce, punch and trim each press stroke. Container Rim Output Increased 300% Novel die set-up and Inland Sheets increase war part production Output cartridge storage container rims, drawn in. deep 8-in. diameter, has been stepped from 400 1200 per day. This increase results partly from die design and die use, and partly from the extremely low breakage Inland Hot Rolled Pickled Sheets. the first operation 0.125” stock blanked and drawn are blanked and draun full depth with 14” shoulder, double acting press. These deep drawn parts are moved another press which are mounted two dies, one for piercing out the bottom and the other for sizing the bottom, which used later close the container. The two operations are performed each press stroke. The rim then taken third press which are three dies, which pierce locating holes, punch out the start keyways, and trim the 8-in. diameter. rim com- pleted three press strokes. Final operations consist spot welding three lugs the inner surface the rim, finish piercing the keyways, and swedging the lugs the rim for close fit. The increased speed manufacture these cartridge storage container rims example how Inland quality steel helping America win the battle production. Each stroke this press pierces out the bottom rim and sizes the bottom obtained duringthe previous press stroke. INLAND STEEL CO. Dearborn Street Chicago Sales Offices: Milweukee Detroit St. Paul St. Kansas City Cincinnati New York alumi 1500 tivel spa tiona resun node] Colun West | viol Prof: thro News AUG. 12, 1943 Fourth quarter essential steel requirements will 4,500,000 tons greater than output, even though estimates put fourth quarter production 500,000 tons higher than quarter. Carbon steels will 4,000,000 tons short, alloy steels 500,000 tons. Northrop's long veiled but now accepted twin motored pursuit bomber with divided body and tail now production with first deliveries scheduled before Bovingdon, the dancer, engaged OEW for economic analysis Far East, according his application could speak and read Japanese, French, Russian, German and Spanish, reads Ceylonese, Javanese, Cantonese and Malay, was once year labor policy and personnel counsellor for American Woolen Co., Boston. was danced out before OEW could evaluate Far from representing sanctions, the recent suspension export licenses Argentina was requested jointly the representative Argentina and the Argentinian government. Purpose was check unsatisfactory consignees; most licenses were revalidated few days. And: the first step toward opening private import and export channels between and North Africa has been taken with lifting the ban against commercial communications. The reason given for cancellation wooden cargo plane contracts, sufficient aluminum production, not the full story. Aluminum production isn't that good. One guess that contracts were given the first place only because temporary sure public opinion. That wooden aircraft are makeshift also implied the same statement. The only operational wooden military craft the British Mosquito; the Germans make their gliders out tubular steel covered with fabric, and even their enormous new (six motors) transport similar construction. Furthermore: the one large plywood transport plane originally had some trouble and had additionally reinforced steel with sacrifice some 1500 lb. freight load. Now production are several machines which will tively harden large caliber steel cartridge cases clip one every seconds space ft. Continuous speed units like this may very likely reshape tradi- tional furnace concepts heat treatment. now the government has been discouraging post war planning aircraft builders, but last week Los Angeles, Pogue, CAB chairman, told manufacturers resume research and development work soon possible peacetime transport Between (most optimistically) Nov. and (most pessimistically) Dec. 31, ship plates will rolled the $150,000,000 DPC Geneva mill Utah, operated Columbia Steel. The same company's $6,000,000 steel foundry Pittsburg, Cal., must pouring within days maintain Navy and Maritime schedules the West Coast. process which plastics, glass any non-conductor may plated has been developed Chicago company which claims that rounded surfaces, corners and cesses are thoroughly covered flat surfaces with plating. For several weeks now the German newspapers and radio have gone violent hate campaign which foul language the predominant characteristic. Profane and fierce invective used casually astonish American listener, Roosevelt, Churchill and the humblest citizen Allied countries the subjects. Big fundamental policy fight shaping question Federal industrial export subsidies. will likely come head first with machine tools and steel. Axis typhus and food destruction rates will likely climb with the loss North African red squill, bulb derivative. Red squill, the world's best raticide, thrown other animals, but rats can't regurgitate. Machine de-burring rapidly replacing hand For example: trigger guards are wet grinding the rate 720 pieces manhours With 720 pieces 240 manhours hand. é if | 4 4 § MACHINED aircraft cylinder head comes off this 176-ft. transfer machine. This photograph was taken the Greenlee shop. The ma- IG. views finished cylin- chines are arranged the form "L" the Studebaker plant. The der head the carrier locating plate. loading point, with head being placed the conveyor, shown Assuming the direction movement the foreground. through the machine toward the sion bottom the page, the cylinder head here, being inverted before entering the producti third unit. Note the routing the center manner section the fins. chines engine reasons large dustry duction mobile improve specific The £ ¥ 7 q 4 IRON AGE, August 12, 1943 — | . | | & 4 aspects, from tool engineer- ing viewpoint, the conver- sion aircraft engine production from job lot proposition mass production procedure has been the manner which in-line transfer ma- chines have been utilized aircraft engine makers, This development was obviously not possible for economic reasons until war demand permitted large scale plane production. Natu- rally enough, developing in-line machining processes, the aircraft in- dustry made use some the pro- duction ideas developed the auto- mobile industry, and modified and improved these processes fit the specific requirements aircraft en- production. The first installation single pur- way machinery for processing Horizontal unit No./ arbors 2-Rough and mill rocker box faces Vertical unit No.2 arbors Rough mill cowl clarnp bosses sketch the three units comprising the Greenlee transfer machine instal- lation the Studebaker Aviation plant. PHAIR Western Editor, THE AGE The second single-purpose Greenlee transfer type machine installed this country for in-line machining aircraft cylinder heads described this report. This unit, built for Studebaker, has several features, including milling operations, not found the first unit installed Wright Aeronautical plant, previously de- scribed THE IRON AGE. cylinder heads large scale the aircraft engine industry was Ohio plant the Wright signed the tooling for the Studebaker tical Corp. second unit this type well for the original Wright has been operation now for Both sets tools were pur- months aviation engine plant chased from Gairing Detroit. the Studebaker Corp. Both these number refinements, together units were built Greenlee Brothers Co. Rockford, Greenlee de- operations Angular spindles (Continued next page) and ream 0896 unit No.8 USF tube pads cow/ chamber alinement spark plug holes Angular wide and round spot face thermo hole /2- Rout five fins and ream 27-Ream and chamfer bore exhaust hole; ream 0.1635 and for thermo hole THE IRON AGE, August 4 ° ° ° ] | ‘ | LJ — { Angular tap unit No./0 No. for spark plug hole for clamp Fixture all holes 2—Rough and finish milling rocker arm boxes, the first machining operation the Studebaker-Greenlee unit. The cutter head moves the right across the cylinder with several significant changes, based large extent upon experience maturing from the first Wright in- stallation, are incorporated this second unit. Credit for these changes must evenly distributed between Mahon washing unit head. the engineering Studebaker and Greenlee. This article will touch upon some the highlights the Studebaker installation, compared with the Wright, Wright installation. For discus- locked. Angular unit No.3 Angular 7- Oril/ (17/32) Rough mill between rocker box bosses sion the philosophy and aspects the use these machines the engine plants, the read- referred the very complete article the Wright installation Linsley Wright, published THE IRON Oct. 1941. Wright installation were lic the chief complaint from the ing Thomases was that possible keep such complex machine operating consistently. downs, they said, would make the ma- chine bottleneck. Apparently they overlooked the fact that the designers the equipment had behind them equally complex problems for the tomobile, refrigerator, washing ma- chine industry, al. Actual experience has substantiated the faith Wright and Studebaker such equipment, for these machines deliver high degree utiliza- tion. some instances, the matter the supply cylinder heads feed the machine has been more lem than the functioning the ma-§ chine. Three Units The Studebaker installation sists three units, all machines The only mechanical | | tap unit Horizontal tap unit Jap spindles clamp and exhaust rocker box bosses exhaust guide rough ream and 10-32 tap for thermo hole mill and x45 deg. 68—THE IRON AGE, August 12, 1943 tion 44% mac ft. chines. machin The accomp ing ope that sons tool ch: the ered fer The unit rocker angles flow The fore man the thi the val show arrang vated § + mie lete shed first ubt- plex eak- ma- they ners hem ving au- ma- ated aker liza- atter feed ing igh 188, dia. 2g. tion between the various units the mechanism. The first unit 44% ft. long with stations and machines. The second unit, 101% ft. long, has stations and ma- chines. The third unit has length ft. with stations and four machines. The stations marked “idle” the accompanying tabulation machin- ing operations are not idle the sense that they are unnecessary. For rea- sons maintenance, inspection and tool changing and the shape and area covered each individual machine, the machines must set certain distance apart. This distance cov- ered positions the trans- fer mechanism. The cylinder heads enter the first unit with the long dimension the rocker box housings moving right angles the direction the line flow the heads through the unit. The head receives deg. turn be- fore entering the second unit and then manually inverted before entering the third unit permit operations the valve throats and guide holes. Fig. shows these various positions. The mechanism for inverting the head arranged that the head first ele- vated and then inverted. held All gular unit No.9 Angular unit No.!/ Three-4 Spindle clusters 27- Drill (0.246) 2/- Ig rocker shaft 22-Combination rough cover holes /6- Drill rocker 23- Line ream 2 9- Ream 0260-0262 for 0.3/1 3-18 USF tap /7- Combination rough L063 spherical tyre for al nement, Mount check ~ Angular unit 2/- Drill rocker in. Angular unit No.8 rough ana rocker shaft Spherical radius radius UNIT Line ream ° ° ° (Continued page) exhaust rocker box 42-Combination 049 and Angular hole 33- Countersink ! Combination taper ream and for 0.250 Angular unit hole into exhaust rocker box taper chamber for 0250 dia. and for 0438-20 USF tap THE IRON AGE, August { FIG. 3—Tapping spark plug holes, holding pitch diameter tolerance in. 4—Plunge milling operation bottom the rocker boxes. The front cutter takes the roughing cut, while the rear cutter does the finishing. this inverted-elevated position for short time permit draining, and then lowered onto the conveyor track. the second Studebaker several milling operations formed the latter unit. The original Wright installation did not cover any milling work. The longest operation the Studebaker unit the milling the rocker box housings. This job, Milling Operations Included The outstanding difference between the first installation Wright and the first operation the machine, quires about sec., including feed. ing, return and indexing. The actual milling requires about sec. This operation, new feature the Stude. baker unit, covers both rough and finish milling, shown Fig. Both intake and exhaust housings are milled. this photograph, the direction the cutter feed the right, with the first cutter doing the roughing work and the cutter mediately following taking the finish cut. Both are cemented carbide cut- ters. stations and the first unit interesting routing job performed with ball milling cutters, the first station, oscillating high- speed spindles follow the contour the outside edge the rib. The diam- eter the first cutter greater than that the second cutter which goes down within in. solid metal the head and which travels parallel the surface. Wooden wedges are inserted between the fins this area before the head loaded avoid breakage the fins during this rout- ing and prevent formation burrs. Fig. shows stations and where spark plug holes are tapped. The tapping tolerance here 0.001 pitch diameter with in. pitch, Class fit. Another new feature the Stude- baker machine the plunge milling operation the bottom the rocker boxes, shown Fig. This opera- Compound angle unit for angle No.20 be, underside hole USF (56 for USF tap drill for 0438-20 USF tap 63-Combination ream and dia. USF ream AL, 99 VO. £2 unit Compound angle No.24 Stub Jap spindles lar tap unit QQ. countersink for 0438-20 USF tap USF tap ana 0438-20 USF tap ace. a holes Check holes Check intake port face remainder holes IRON AGE, August 12, 1943 tion the blade nel has posit Fi; unit, push from the diate ism. vane umn tapp engil ing these tion been twee port : Angu 0. the second unit. This operation performed Gairlock inserted blade tungsten carbide tipped chan- his nel milling cutter. Note that the head has been turned deg. from the Fig. shows operations performed unit, back chamfering and tapping push rod tube holes. This view, taken from station looking toward station 52, also shows gage for checking shaft from the checking unit leading limit switch can seen imme- rst diately beneath the conveying mechan- ism. This limit prevents ad- vancing the line while gages are still the work. Note also the limit switches mounted the machine col- umn the left. Stub Boring tal Fig. shows stations and where the intake port bored and are tapped. Fig. interesting close- oid operation the third unit. Greenlee engineers are exponents stub bor- ing and have used extensively these units with success. This opera- tion covers stations and the 001 third unit. Note that the head has been inverted for this operation. The Mahon washers installed be- tween the first and second units, the second and third units and the end ker the line were originally developed ~ a. lar tap USF fap rocker box 0438-20 USF cover holes Angular tap unit No.3/ USF tap cham- fering and tap- ping push rod tube holes. Note the gaging fixture row) the fore- ground which in- terlocked with the mechanical transfer Mahon washer (Continued next page) Angular and unit 3.5804 form 0.080-0.090 radius form with dia. cutter and for exhaust wide boss, bore bore form corner rough THE IRON AGE, August 4 4 7 nati e use Varsol. However, was found that was not possible separate the Varsol and the cutting oils. Hence the washing machines are now operat- ing the No. cutting oil (See be- low) and separation problem involved. This “washing” operation largely matter flooding out the plates. follows: Sinclair Union part No. No. 560 (Swan Finch) Check alinement intake and exhaust valve guide holes and insert seat washer Mahon Angular unit No.4 /4-Combination spottace exhaust guide box, bore dia, form chamfer corner deg, rearn 0.937- 0.936 dia, and chamfer finish 25806 dia, finish form deg. chamfer corner, finish chamfer with ream 0.9676-0.9674 dia. 72—THE IRON AGE, August 12, 1943 chips from the holes and cleaning off Cutting oils used Studebaker are No. 5—Mineral seal oil—20 parts The first unit uses the No. mix- ture which seems give the better cooling needed for the large number tapping operations performed there. The other two units use the No. mixture. The chip and oil handing system these machines also interest. The coolant pipes the work are all equipped with cut-off valves operated the movement the machine heads. Thus, when the head progressing into the work the coolant flows, but soon the actual cut- ting completed, the withdrawal the head shuts the coolant flow off. Beneath the machines gravity feed chip trough which slopes settling tank equipped with and screens. After passing through this tank, the oil recirculated. The effect the shutting off and turning the valves during each machin- ing cycle gives surge the flow the coolant the troughs. This surge has been found much more effective moving chips down the trough than steady flow cvol- ant. addition the regular inspection stations, this new installation also has stations check holes, location and depth before tapping. Milling work checked immediately after the op- eration. These inspection stations are valve guide the hec proc throats interlo Fig. The such specific the for inc ened illustr The with that and been makir place condi was ing ing and reaming valve insert seat and guide holes the third unit which the head inverted process the valve throats and quide holes. interlocked with the machine, shown Fig. The tool changing operations such units cannot covered specific policy due the variances the tolerances which must held for individual holes and also the fact SIMPLE idea that improved the consistency accuracy with which milling cutters can sharp- ened shown the accompanying illustration Ingersoll machine. The grinding machine provided with carboloy-tipped finger "A" that follows the contour the tooth and quides the grinding wheel. Guide fingers made alloy steel, has been found, wore away very rapidly, making frequent adjustments re- placement necessary. correct this condition, cemented carbide tip was brazed the finger after mill- ing recess. The hardness the carbide vastly increased the life the finger. that certain operations cause higher tool wear than others. However, ex- perience has indicated when certain type tool may expected wear out and effort made anticipate this making change during the shift changeover The contrast tool life unusual. For example, the drills the valve guide holes have changed every hr., while the original carbide insert milling cutter the push rod pads was still service after some 20,000 hr., and still has appreciable life left. m ill ed eavy Gun Tubes from Seamless new way making heavy gun barrels from seamless steel tubing, enormous savings time and materials, has brought Timken Roller Bearing Co.'s monthly output heavy guns higher level than all England's heavy gun output during the entire war. Formerly such gun tubes were forged. The pictures this and the following pages illustrate Timken's new seamless tube method. ity LEFT bars steel rolling in- the piercing mill furnace are their way becoming the shooting end guns. Grav- ity gradually draws them, red hot, bottom furnace. RIGHT Heated bars are down slope fur- ; i | 4 fe are : 4 RIGHT 3—Ram forces 84-in. bar from side door lower end furnace. Grav- ity conveyor carries pierc- ing mill. ars in- LEFT nil More than hr. pro- duction time are saved boring the gun tube. Piercing takes seconds. Former forging and drilling method re- quired hr. for this one operation. RIGHT 5—Rolling mill, into and out which newly-pierced gun tube raced. Inner walls are further smoothed, and tube rerolled greater accuracy. — BELOW IS. Red hot end shoved in- forging machine, and ready for finishing. Tubes right have already had rough ends removed. save steel, tubing made diameter gun tube, not diameter breech, before. Heavy Gun Tubes from Seamless Tubing LEFT Electric induction furnace heats breech end before upsetting form breech. tied ing, 76—THE IRON AGE, August 12, 1943 7 ABOVE IS. 10—Half-opened forging die reveals freshly formed breech. Upsetting size from gun tube-sized tubing rather than machining, casting, forging breech from bar breech diameter requires considerably less time, reduces scrap, saves strained melting facilities, too. ABOVE IG. Under this sheet flame, gun breech has been formed sec., using ordi- nary upsetting ma- chine. RIGHT end breech end tubes may car- tied vertically ing, hardening, and tempering furnaces. 7 THE IRON AGE, August 12, RIGHT IG. 15—Tubes are tumbled into pickling vat wash away heat scale. BELOW IG. 14—Stamping code num- bers. Each tube numbered indicate when its steel was made, whom, the analysis, whether came from top, center, bottom ingot, etc. LEFT 12— Device lifts tube con- veyor system moving steadily through heat treating One production line capable pro- ducing 6000 75-mm. gun tubes month. RIGHT 1S. mm. gun tube fires its first shot—out the breech end. the red hot tube em- erged from heat treating furnace and was being lowered into water quench, steam built side and blew water out top. aff — te ABOVE steel sawed from tube goes into testing laboratory for macro-etch inspection. BELOW IG. makes final check-up. Here inspector uses tell-tale gage determine concentricity inside diameter. laboratory approves sample, the gun tube loaded into freight car. ABOVE IG. small squares are sawed from ring machined into physical test specimens for determination yield strength, ductility, Gun tubes made seamless steel tubing have less chance failing. BELOW IG. 19—75-mm. gun tubes exit end con- tinuous heat treating conveyor line, novel time- saving feature Timken-developed process. Tubes are shipped government arsenal for finishing. 4 4 i Plastics Temperature, pressure and time are the three elements involved forming any the engineering materials, they metals non- metals. Before developing some the plastic methods working them, Mr. Crane the third part the article discusses casting methods since injection molding plastics form die casting. Compression molding began with the ceramics and the same prin- ciples apply molding powdered metals, the author points the fourth part, forming synthetic resins analyzed. list materials, both sim- ple and complex, which are pres- ently passing through chemical and physical adolescence into utilizable engineering materials reduces those which were familiar the turn the century numeri- cal insignificance least. The most complex are nature’s recipes—wood, stone and clay—which whittled, pounded molded useful shape rule thumb methods through the ages. The newest are the synthetic alloys and mixtures which the substitution orderly science for art, have been made available and tractable for the greater good the greater number. the fog experi- mental manufacture lifts from each usable arrival, found form- able the orderly application nature’s own routine, e., tempera- ture, pressure and time. Hence, seems worthwhile note what may involved varied combinations form with temperature, pressure and time. Form implies some combination Copyright, 1943, Crane. Langhammer, Milton Smith, Amplex Division, Chrysler Corp., Powder Metallurgy, A.S.M., 1942. Fig. 183a, 213 and Fig. 291, 306, Plastic Working Metals, 2nd edition, John Wiley Sons, 80—THE RON AGE, August 12, 1943 usage, art and purpose. For manu- facturing purposes the form must translated suitable engineering dimensions, and thence “tools” (molds, dies rolls) suitable for re- production the form part the selected material. compared with common knowledge casting, pri- marily molds made sand and .clay, and forming primarily dies and rolls made hardened steels, there now available diverse choice and usage tool materials ranging from confined steam, water and rub- ber plastics, plasters, wood well cast, rolled and powdered metals, including sintered carbides reinforced with prestressed alloy steels. Gov- erned always comparison costs tool material and tool fabrication with useful tool life, the material must capable standing the tempera- tures and pressures involved. Fur- dissimilar nature the material being formed avoid galling (pres- sure-welding inter-molecular co- hesion). Temperature Ranges Temperature required manufac- turing processes may vary from sub- zero, forming cakes carbon ° ° CRANE Chief, Development Engineering Depart- ment, Bliss Co., Brooklyn dioxide ice, that the electric are, producing synthetic abrasives. Temperature must often controlled within rather narrow limits for cess. Several general temperature ranges should recognized, fol- lows: material frozen set its tal pattern, although that arrange- ment may disturbed pressure working the pattern sufficiently simple allow crystoplastic form- ing Recrystallization range electron activity becomes sufficient for atomic molecular readjust- ment, stress relieving and annealing Thermoplastic range tallization fluidity, which thermoplastic material may moved about more freely tem- perature rises, within purely me- chanical limits movement Fluid range, for casting pur- poses, which interatomic inter- molecular bonds are rendered tran- sient heat solvent Gaseous range which atoms and molecules space themselves quite independently (This also enters soluplastic and solusetting processes where liquid solvent must evaporated “dried out’’) Heat treating range which dis- persion hardening suitable crys- tal grain size established, and Thermosetting range certain mixtures which chemical change adhesive constituents takes place prescribed temperature. most not all these the temperature range limits are subject varia- tion tern relativ and conside dling cooling cleanir whethe Pres vacuun solutio screen tons sion tions materi cavitat and require rigid tions. Time dimens cient plete stress drying step distine ties, handic initial quired comple the che lief ductior ] | ROD ost tion with internal stresses ex- ternal pressures. that the commercial aspect relative expense governs the success competitive enterprise, investment and operating charges receive primary consideration every step. Heating equipment cost, fuel charges, hot han- charges, temperature control, cooling costs, cleaning, washing and drying costs are whether process temperatures are high low. Pressure Factor Pressures may vary from near vacuum, used distributing from solution, paper making and screen molding, hundred more tons per square inch severe extru- sion and cold forging operations. In- creasing flow speeds, greater restric- tions flow, more viscous tougher materials, more severe restrictions cavitation and entrained gas flaws, and closer tolerances finished parts require ever more powerful and more rigid machinery cope with condi- tions. Time Factor Time the fourth -ingredient manufacturing recipes and “the fourth dimension” the process chart. Suffi- cient time must expended com- plete precisely the feeding, heating, stress relieving, chemical drying, discharging whatever the step may be. every case, time distinctly money. The synthetic plas- tics, for example, have been definitely handicapped competitively initial development the time re- quired (in expensive equipment), complete the transmission heat and the chemical change set, the re- lief intermolecular strains. The re- duction time per unit through MOVABLE PLATEN COOLING CHANNELS | NOZZLE larger quantities process and more efficient processing equipment the essence American mass production. Casting Process Plastic working, first metals and now many more materials, seems properly limited the several plastic states (see preceding article). Indul- gence requested, however, for some consideration the fluid state involv- ing casting. Casting the pouring fluid material into suitable mold har- den set simple but may readily quite troublesome. Tendencies are common shrink, entrap air bub- bles, produce gas bubbles shrink- age voids, crystallize set non- uniformly with internal strains, erode the mold and pick dirt impurities, and segregate the case mixtures, giving non-uniform chemical and physical properties. Solvents, such water, oils, alco- hols, esters, render many mate- rials and mixtures fluid for casting. All require considerable time and pos- sibly heat for drying and the more expensive solvents must recovered for economy.. Conerete poured earth, wood and metal molds. Mag- nesite building materials may also poured laminated plastic molds with rubber cores for easier stripping. Wood pulp, wood flour other or- fibers with suitable binders may 19—A typical injection molding die and heating chamber for ther- moplastic. The balance the injection molding machine includes pressure means the one side for closing and holding the mold, and the other, for forcing heated charge into the mold, to- gether with adjusting and cycle control means. Courtesy Tennessee Eastman Corp. | RMOCOUPLE cast screen molds with the aid air pressure suction papier- mache and similar work progres- sively screen belts rolls starting paper, belt board manufacture. Heat expended melt fluidity many materials extending from the waxes and resins the glasses and steels, each its turn representing wide variety chemical analyses. Casting, like molding, deals with or- ganic, synthetic, ceramic and metallic materials, reminding the scope the present engineering outlook. addition casting troubles already noted, the tendency many hot mate- rials unite detrimentally with oxy- gen must met frequently. brief review common casting methods may prove helpful for the light such review may throw upon subsequent Molds and Patterns Molds for casting iron, etc., are ordinarily made sands selected for grain shape and size (to assure gas venting), bonded with small amounts clays sufficient heat resistant capacity for the high temperatures involved and probably reinforced with rods, wires, nails, etc., withstand stress erosion. While originally shaped hand, and later, with tools and sweeps, pres- ent practice mold requires pattern formed the desired shape. built into the mold such way that the mold may separated two more parts successfully remove the pattern and insert baked sand and clay cores, thus leaving cavity the shape piece required, just enough larger allow for shrinkage. production and precision demands increase, pattern materials vary from soft woods, hard woods, plaster paris and possibly plastics single GRANULATIONS LINER THE IRON AGE, August LPLUNGER CYLINDER | 'S- n- ch ° ° ° m- | | SPREADER’ and multiple metal patterns arranged for rapid reproduction sand molds with mechanical assistance. For brass and bronze castings, semi-permanent plaster molds help reduce mold cost per piece. Metal molds and machine handling methods have made produc- tion history the manufacture articles from molten glass. Die Casting Practice Die casting combines long life metal molds, mechanical mold closing and holding, molten metal injection and final stripping the chilled casting. another forward stride mass production accurate castings. first, tool steel dies worked well for the low melting point “white metal” alloys lead, antimony, tin, zinc and later aluminum. Soon thereafter, the more heat resistant die alloys made possible the die casting higher melt- ing point brasses and bronzes. Injection Molding Injection molding applies much the machinery and technique die casting the production parts made from synthetic resins other adhesives and their mixtures. Fig. 19, the powder mix prepared suitable granule size (3/16 5/16 in. for Tenite, cellulose acetate cellulose acetate butyrate) delivered from hopper measured volume the path the injection plunger which forces the charge through the heating chamber and into the die cavity from which the finished part ejected the die opens. Production cycles are governed the time needed for application and dissipation heat suit the particular mixture and permit possible die cleaning and ap- plication inserts. Tables III and the preceding article give data available for typical materials. more than one injection unit used, care must taken avoid flaws the joining weld due the first bit defective material, joint lines due slightly different shades different hoppers color work. The press close and hold the die and knock-out the molded part parts upon opening, may either hori- zontal machine (to drop out small parts) save floor space may vertical inclined press (espe- cially for large parts). Injection Pressures Injection pressures necessarily vary both with the interferences flow the narrow and intricate passage- ways, and with the viscosity fluid- IRON AGE, August 1943 dynamic" molding press with bottom cylinder. Its this application favors variety metal powder press- ing operations. ity (through changing temperatures), various proportions the many resins, flow aiding plasticizers and possible pigments and fillers. The chemical companies recommend pres- sures 2000 50,000 per sq. in. for their various combinations, and long thin die passageways may raise the requirement 100,000 lb. per. sq. in. more. For this reason some ma- chines have provision change pis- tons and piston sleeves and all permit pressure control. Holding pressures should figured around per cent the product injection pres- sure and projected area the die. Although considerable pressure lost driving viscous material rapidly through the constrictions the heat- ing chamber and nozzle, the pressure holding the die closed must the safe side insure against flash. Heat and time cycle relations in- jection molding depend upon whether the material handled thermo. plastic thermosetting. lesser extent the cycle relations also depend upon the heat range the binder and that the plasticizer and the pro- portioning the die sections. Thermoplastic materials heated and reheated that they need not rush too fast through the heating chamber, and their sprues and trimmings may granulated and used again. Being poor conductors heat, materials this class must separated through passages small cross-section, 19, get the heat into them. The walls such heating chamber aie hotter than the material, that halt machine operation requires that heating stopped heated material ejected before re- suming operation. Thus, ester plastic which should injected 385 deg. might require cylin- der wall temperature 420 deg. but standing that temperature for min. would likely cause dark- ening charring. normal cycle there would danger overheat- ing. Again, due slow heat trans- mission, the molded part might too soft ejected without damage un-§ less the die were cooled some (say 100 200 deg. F., upon the resin and plasticizer). this reason, such materials are times confusingly Too low die temperature cause improper filling strains and strain markings the material that dies must Fig. suggests the temperature-time relationship necessary for material its thermoplastic state relieve and readjust its molecular structure its new chilling. Thermoplastic material must arrive the die cavity enough and stay there long enough stress-relieve and incidentally enough that cools sufficiently resist bump ejection. Thermosetting materials may jection molded heating the dividual charge very quickly (by duction dielectric heating) getting right into hot die take shape and hold long enough heat polmerize and set. Due the chemical change that when the temperature reaches pitch for molecular combination the resin constituents, sprues and gates cannot The tion const conve take trimr must flush ple body, for ing ing, from due mark need hole. holdi shoul holes | halve ting re- eing Fig. The ale ylin- for cycle min., dset- will -time cular efore then hot long erials in- and take the the place ion scrap raged. The hardening hot setting or- dinarily sufficient permit safe ejec- tion without cooling. Die Design Dies molds, Fig. 19, are leaning design toward well known die set construction, with guide pins for convenience setup. Sprues are tapered for stripping and cavity furnished opposite the sprue take the chilled slug from the end the nozzle. This cavity located the defective material can trimmed off avoid damage the appearance the part. Knockouts must substantially backed hold flush under pressure. Gates multi- mold dies must not small restrict quick fill. the die body, passages are usually required permit circulating cooling water for thermoplastics steam for heat- ing thermosetting materials. Vent- ing, especially the point farthest from the entrance, must provided avoid incomplete fills and charring, due trapped air and steam. The latter may also cause markings that precautions are es- sential keep powders from taking atmospheric moisture. Vents often need little more that scratch most 0.025 in. outwardly tapered hole. The land area contact between halves the die around the profile the mold molds and gates should holding tightly. Contact surfaces should lapped. Passage and sprue Many holes should well polished. materials contain abrasive plastic constituents and few like vinylidene chloride and vinyl chloride acetate react chemically with steel (also cop- per) and make advisable that dies and heating chamber parts chrome plated. Shrinkage allowances must made suit both molding temperature dif- ference and time shrinkage recom- mendations for the particular mate- rial. Molding pressure and uniform- ity section the piece and the entry gates are also said affect shrinkage. Compression Molding Molding, preshaping and concur- rent subsequent heating, sintering though not always too clearly, from the foregoing “casting” methods which material rendered fluid semi- fluid before entering the mold, cools sets the shape the receiver. Historically the method dates back clay bricks and pottery which were molded hand and baked slowly the sun and later more quickly fire. The low production foundry tech- nique molding sand with clay binder (for subsequent casting) hardly more advanced. Under such titles compression molding, briquet- ting, pelleting, preforming, etc., the method advanced the machine stage the production pills, but- tons, grinding wheels, carbide tools, porous metal bushings, welder tips, tiles, plywood and other laminates, crockery, building blocks, insulators, knobs, tires, caps and endlessly. ° ° ducing oil impreg- nated porous bronze and iron bushings (Fig. 22) hy- draulic presses (Fig. 20) the die the left measures the charge and briquettes for sintering, after which the right hand squeezes irons the bushing pre- cise finished size. Molding Ceramics Ceramics, compression molded for general and industrial use, may typified Westinghouse Prestite. Its composition given flint, feldspar, China clay, ball clay and water. These are mixed, filtered, ground and mois- tened with water properly plastic consistency for molding conven- tional hydraulic presses and dies. The molded pieces are conveyed through ovens for drying and then baked un- der conditions accurate tempera- ture control set and glaze. Actually, each the clays, chosen from deposits mined different local- ities, contains different percentages about the same six eight oxides plus chemically combined water, which the plasticizer. Thus, flint clay contains about per cent per cent per cent each and CaO plus traces couple more oxides and about per cent water chemical combina- tion. The analysis ball clay given much the same but with less CaO and about per cent Crystalline feldspars, such are alumina silicates potassium, sodi- um, calcium and rarely barium. This suggests the chemical complexity writing formulae for concretes, cera- ics and other natural plastics, not- withstanding the fact that the tech- nique handling them was worked out quite well the ancients. Soluplastic and thermosetting seems like proper way identify the process although some the same oxides melted into glass definitely add thermoplastic characteristics. The washed and ground clays are soluble ( THE IRON AGE, August 1943—83 22—Straight-sided and inclinable presses used the Chrysler-Amplex division the mass production from powders Oilite bronze and iron bearings. Courtesy The Modern Industrial Press. water which makes possible control consistency for molding. When heated the setting temperature, which varies over considerable range dull red (dependent upon con- stituents), the mixed molecules lose their chemically soften and contract, similar re- processes other materials. They cool typical stone-like porcelain which ferences recrystallization range the different oxides and propor- tions natural mixtures necessarily complicates the control. These mold- mixed oxides take metal inserts reinforcements well adhere en- ameling steels protective finishes. 84—THE IRON AGE, August 1943 They may machined between dry- ing and baking and ground after baking. They take color glazes, are relatively brittle and show tensile strengths about 5000 per sq. in. compared with 48,000 compression. interesting cross between mold- ceramics and powder metallurgy found certain (Permalloy) tele- phone and radio cores. Here, for high magnetic permeability, granules iron and nickel molybdenum are prepared and coated with thin film (0.00062 in. approx.) ceramic clay insulator eddy current losses. The coated granules are die pressed shape under about 100 tons per sq. in. pressure density about 7.75 and annealed restore magnetic quality, and, incidentally, temperature which sets the ceramic binder. Abrasive wheels are molded with pressure, temperature and time com- binations suit the particular mix- ture. The fillers the mix are the hard, sharp crystal particles, silicon carbide aluminum oxide iron oxide, for grinding purposes, with such binders rubber, the clays, phenol-formaldehyde other thermo- setting resins. Metal insert hubs shanks may molded place. Hy- draulic presses and heated dies are used for the resins and rubber cold pressing followed drying and baking, for the ceramic clays. Cemented Carbides For cutting edges, drawing, extru- sion, heading and cold forging dies, spot-welding tips and other points application severe and abrasive stress, cemented carbides combine such hard filler materials tungsten car- bide, tantalum carbide and titanium carbide, with such binders cobalt, nickel and copper. Suitable sized and shaped powders are cold compressed steel dies and hydraulic presses and sintered baked reducing at- mosphere, well the recrystalliza- tion range the binder, pressed similar temperatures low pressure (1000 per sq. graphite molds, with time allowances for recrystallization the binder. The latter method would make for greater density, die materials were available which would stand prop- erly both the pressures and temper- atures desired. While compressive strengths the cured mixtures reach 500,000 nearly 900,000 Ib. per sq. in., the much lower tensile strengths are derived from the per cent relatively low strength binder that the carbides are often molded directly into steel holders rings. Similarly, powdered copper and tung- sten carbide tips molded directly solid copper electrodes combine con- ductivity and wear. Molding Metal Powders Metal powders many types are compression molded, following much the same rules govern the thetic resins discussed tion with Figs. and and Table Fundamentally, suitably prepared powders are pressed dies suit- able density and intimacy particle contact. Heat for the welding bending may applied either during pressing more monly after pressing the sintering Subs tions ings, press medi: quire want and comp rial usua mesh tion are resir what sizes and some tions and abov simi mov half and = t