The Iron Age 1943-12-16: Vol 152 Iss 25

DECEMBER 16, 1943 First ation see bush- Lathe. One freight-carrying giants Fairbanks-Morse Scales and Fairbanks-Morse Crane Scale. Scales War Fairbanks, Morse Co., Fairbanks-Morse Building, Chicago Illinois BUY WAR BONDS 943 end. ing All day today and all night Straight through every minute the hours your Cleveland Worm Gear Speed Reducers stand competent guard—they deliver depend- able power keep equipment going, come what may. That’s what built course—yet Clevelands’ almost endless capacity absorb punishment and keep driving ahead one the things that the oldest customers mention most often with greatest appreciation. quote from just few:— “Our Cleveland Units have run hours day for years ... have never opened the products industry. hours day beginning 1929—our Cleve- lands get special metals. “For nearly years Clevelands have given uniform operation, minimized and brass. “Day and night since 1923; Clevelands insure uniform operation” —portland cement. the clock for years—Clevelands keep our equipment rubber. “Our equipment must run continuously—Clevelands have prevented shutdowns here for more than industry. Designed and built for peace, Clevelands today are doing big wartime job. Count them stand you always—all day today, all night tonight. The Cleveland Worm Gear Company, 3252 East 80th Street, Cleveland Ohio. Affiliate: The Farval Corporation, Centralized Systems Lubrication Canada; PEACOCK BROTHERS LIMITED SPEED REDUCERS THE IRON AGE, published every Thursday the CHILTON CO. Entered second class matter November 1932, the Post Office Philadelphia under act March 1879. vearly North America and South America, Foreign $15. Vol. 152, No. our today them all 3252 brication Office VAN DEVENTER President and Editor BAUR Vice-President General Manager ° ° Editorial and Advertising Offices Johnson, Market Research Mar. Hayes, Production Manager. Baur, Typography and Layout fo] ° ° Regional Business Managers OBER New York 100 East 42nd St. LEONARD New York 100 East 42nd St. Cleveland 1016 Guardian Pittsburgh 428 Park Bidg. Philadelphia Chilton Bidg. PEIRCE LEWIS Detroit Woodward Ave. Chicago 1134 Otis Bldg. WARREN Hartford Conn Box RAYMOND KAY Los Angeles 2420 Cheremoya Ave. ° Owned and Published CHILTON COMPANY (Incorporated) Executive Offices Chestnut and 5éth Sts., Philadelphia 39, Pa., U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH GEORGE GRIFFHHS EVERIT TERHUNE VAN DEVENTER BAUR Vice-President Vice-President Vice-President Vice President Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE BUZBY HARRY DUFFY THOMAS KANE FAHRENDORF CHARLES HEALE Member, Associated Business Papers ° Indexed the Industrial Arts Index. lished every Thursday. Subscription Price North America, Sout America and Possessions, $8; Foreign, $15 year. Single Copy, cents. ° Cable Address, ° Copyright, 1943, by Chilton Company ° ° ° ° Pub- Features AGE Vol. 152, No. Mr. Baruch Has Bicycle Technical Articles Shaved Aircraft Gears Tubes and Tube Making Effect Lead Steel Mass Production Steam Turbines Large Gate Valve Built Arc Welaing Gas Pipelines Increase Welder Prod: New Equipment—Gages and Small Toois ° News Front Assembly Line Washington West Coast Fatigue Cracks Dear Editor News and Markets Another List Seized Alien Patents Converting Contracts Incentive Basis Plastics Replaces Aluminum Bombers Steel Developing Cancellation Policy Personals and Obituaries Machine Tool News Non-Ferrous Metals News and Developments Non-Ferrous Metals Prices; Scrap Prices Iron and Steel Scrap News and Prices Comparison Prices Year Finished Iron and Steel Prices Steel and Warehouse Prices Stainless Steel, Tool Steel Prices Semi-Finished Iron and Steel Prices Pig Iron Prices Ore and Coke Prices Ferroalloy Prices Index Advertisers December i6, 100 118 128 130 150 152 154 155 156 158 159 160 161 161 163 164 166 229 i ia ° Member, Audit Bureau Circulations Z Ryerson Steel Sunday, September 12, 1943....A disastrous fire destroying the train sheds the Pennsylvania Railroad’s great Broad Street Station Philadelphia, all important rail nerve- center, vital the Nation’s war effort! This calls for action! One thought every Pennsylvania man’s mind —rebuilding—restoring service—the quickest possible way. Construction materials are needed but how get steel? 3:10 P.M., the fire still burns fiercely. The railroad’s purchasing his home. The order for 60-foot channels. Can Ryerson deliver? Ryerson can—and does, just one hour and twenty minutes! 4:30 P.M., Ryerson truck pulls the blazing station with the steel! Before werecold, the rebuilding Broad train sheds was started. Good service? Yes, say Pennsyl- vania officials! Co-operation emergency avoid tie-up vital RSON are, Delivered While the Fire Still Burns war facilities? Yes! Proof that “steel stock for immediate shipment” Ryerson reality. Proof that the Ryer- son organization ready and able meet every steel-service requirement, however tough. any emergency—and your everyday purchases—you can depend Ryerson for steel. Call, wire write the nearest the ten well- stocked Ryerson plants. JosephT. Ryerson Son, Inc. Plants at: Chicago, Milwaukee, St. Louis, Cincinnati, Detroit,Cleveland, Buffalo, Boston, Philadelphia, Jersey City. — | | q 7 7 q IRON ESTABLISHED 1855 ° Dec. 16, 1943 ° ° VAN DEVENTER President and Editor BAUR and General Manager ° DIX Manager, Reader Service ° ° ° News, Editor...D. JAMES WINTERS Associate Editors MacDONALD BARMASEL Editorial Assistants SCHIEN BUTTERS News and Technical CAMPBELL Pittsburgh 428 Park Chicago 1134 Otis MOFFETT DONALD BROWNE HARDY Washington Press Bldg. LLOYD Cleveland 1016 Guardian BRAMS Detroit 7310 Woodward Ave. OSGOOD MURDOCK San Francisco 1355 Market St. Editorial Correspondents ROBERT PENLEY Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE Birmingham ROY EDMONDS Louis JAMES DOUGLAS Seattie Mr. Baruch Has Bicycle NDUSTRIALISTS and business men general welcomed the appointment Bernard Baruch director post-war economic adjustments. Mr. Baruch universally admired and respected; has intimate knowledge the needs makers, merchandisers and con- sumers and unquestioned good judgment. his capacity chief reconversion engineer the United States, Mr. Baruch will have the support the rank and file our people well those who direct the management the manufacturing and selling goods. other words, will have plenty support. from below. How much support will get from above another question. Any man charged with the responsibility directing the changeover nation’s industry from war peace has long way very short time. cover this distance, Mr. Baruch has been given title. But has not, apparently been given even bicycle. What really needs help all win this race against time not merely bicycle but the finest and fastest streamlined conveyance that the country can supply take him from here there. The mechanism that Mr. Baruch will need, and that the American public will need, put his ideas into effect ably staffed body, organized and experienced every branch industry and business, that can act swiftly, decisively and with authority any situation that may arise. This the only sort reconversion conveyance that will reach the post-war objective time prevent disaster, the closing factories and the laying off workers. Ironically enough, there such conveyance already built and func- tioning well the form the War Production Board. has done splendid job organizing and directing our industrial war efforts. has been manned, and still is, some the best men country. But these men are the type who not stay train after has reached its announced destination. Already some these men are getting off the train because they think its destination has been reached sight. But not sight many miles many months. the chief train America tell these gentlemen that the journey only half over when the war finished and that they should not get off the half way Right now the time for the Supreme Commander American In- dustry and Business take time off from his job Commander-in- Chief our Army and Navy and add just one syllable the title the War Production Board. Make the Post-War Production Board. And give Mr. Baruch ticket ride this streamlined conveyance. What world difference that extra little syllable would make! | 4 4 f ‘ ¢ . F : | : 2 Fi J = 4 | f | 7 4 >] a | ; | | 2 7 4 = Jimmy anxious see his Dad— his Mother working for Victory. Mother now head the crane hookers one the Inland departments. Jimmy’s Dad Fights, His Mother Works, Help Bring Victory Little Jimmy’s Dad, Sgt. James Maloney, doing his bit Air Force fighter squadron win this war. mother doing her bit, too, head the crane hookers Inland Steel Co. department. Sergeant Maloney left Inland enlist Sep- tember, 1940. Jimmy was only about five months old when his Mother, also former Inland employe, re- turned work. She wanted her part, along with Sergeant Maloney, hasten the day when peace will return and Jimmy will see his Dad for the first time. St. Milwaukee Detroit St. Paul St. Louis This little family story typical the American spirit for spirit which moves men and women all their power help supply fight- ing equipment needed America’s fighting men crush the enemies Democracy. you know man, woman, not now war work —some person who can take place industry left vacant fighter? so, urge him her join the ranks war workers and hasten the day when Jimmy’s Dad and all the other victorious Yanks will come marching home. Chicago Illinois Kansas City Cincinnati New York 4 | | News Shipping unsheared plates from Republic's Cleveland strip mill shipyards will increase cost much $2.89 ton because increased freight and differential scrap price ceilings Cleveland and the shipbuilding centers. Republic will also lose the scrap itself. Ford Motor Co. now operating sulphur extraction plant purify coke oven gas. About six tons per cent pure sulphur are extracted daily from the 000 cu. ft. coke oven gas produced every hr. the Rouge plant. reducing corrosion the heat treat furnaces, magnesium smelters, armor plate building, etc., Ford officials estimate three-year liquidation cost. Holders large steel inventories the New York area are moving stocks through WPB's Redistribution Department. Rather than caught with large stocks the event sudden victory, they are selling quantities below ceiling. With aluminum already challenging copper for second place metals production, and secondary aluminum slated low after the war, prices for sand castings may challenge iron steel castings. The automobile industry said contemplating use from 200 500 lb. aluminum every automobile. facilitate the reabsorption workers released War Department ing, cutbacks plant shutdowns, the War Manpower Commission will notified suth orders. Increased cutbacks will stimulate unions mass production industries demand the 40-hr. week. While seeking shorter hours, effort keep higher wages will continue. Failure rollback prices the reason given. Allied raids German synthetic rubber plants are actually not directed toward the synthetic plants but rather toward carbon black installations, the critical ponent bottleneck rubber production. What many would like know sudden bonanza copper and brass? Steel shell cases and cartridges are being switched back brass; steel clad with gilding metal being killed off; and fuse parts (several pounds apiece for each large bomb) are being converted from malleable iron back brass. Meanwhile: The steel situation shows easier supply situation, whereas copper mining was classed month ago WPB highly critical, with manpower directed even the detriment all other mining operations. The shift back brass confusing view the elaborate publicity put out Ordnance regards mastery engineering and metallurgy details steel cases. Total capital now invested German industry about 30,000 million ($12,000,000,000) equivalent several months' American war output. One the Luftwaffe's "backroom" boys, Fliegerstabsingeneur Hans Busch, address before Swedish aeronautical experts predicted the appearance soon 6000 hp. motors, and stratosphere airplane with ceiling 79,000 ft. American experts expect the former, are skeptical the latter. The use Russian women for operational flying seems puzzle German gandists. While some state that these women are poor pilots, others point out that among fighter units made female crews are several which are Chevrolet looking forward early production passenger cars. The company has sufficient plants and standby facilities maintain its aircraft armament program producing civilian cars branch plants. The ban migration war workers into Cleveland has been lifted USES. The city has now been declared area acute labor residents can found fill war job vacancies. ~ i 2 | | | I. Ci CAS Many plants have tried solve the problem distortion subsequent heat treatment use press quench fixtures. Avoid- ing the use such fixtures, this plant has found that proper con- trols, the amount distortion can made uniform enough anticipated modification tooth form the shaving operation that the end result the desired involute. IRCRAFT engine gears from the have been designed from the point view grind- ing rather than shaving and manu- facturing facilities obviously corre- sponded. was natural therefore that when this plant was first equip- ped for the sole production gears for the Wright model 1820 1200-hp. engine, the emphasis was placed grinding. number gear grind- ers both the generating and form wheel type were installed and only recently that four shaving ma- chines were purchased handle the production just one the 43-odd gears all types this engine. More gears are under study for pos- sible conversion shaving. the other hand, most the pro- duction executives this organiza- tion have background experience the manufacture automotive gears wherein shaving has been the accepted practice for years. With this background, was only natural seek out gears that adapted them- selves shaving and make the conversions. Now that production runs are be- coming large enough, the advantages economy and even finish begin show up. The four shavers displace generator type gear grinders and shows substantial savings the pur- chase additional grinder equipment for current expansion program, since the grinders originally used the shaved pinions can released for new work. Machine for machine, pro- duction the ratio 5:1 favor shaving. The higher the hourly output re- quired, the greater the economic ad- vantages shaving over grinding. his paper* gear shaving pre- sented before the SAE last spring, 44—THE IRON AGE, December Harris Chevrolet Motor Division General Motors indicated that the example one gear, production were less than 2.9 gears per hr., there was economic advan- tage shaving over grinding. Here “Shaved Gears for Aircraft Engines”, 1943, 58. Studebaker, over 100 shaved gears per hr. are processed. Precision shaving built into the machine and the cutter and the human element virtually eliminated. grinding, the other hand, errors checks and burns are all the result factors control the operator who may sacrifice quality obtain quan- tity under piecework system. Pro- filometer tests show better average surface finish shaved profiles than ground ones, which usually must lapped remove the grinding ° ° ° pinion which now being success- fully shaved. Formerly the tooth pro- files were ground after hardening. TEETH Whole depth addendum Q3032" Circular pitch pitch Material: AMS 6250C ° ° ° Ivan Calicoat Gear Supervisor, and Curt Payntor Studebaker Avia- tion Division, Studebaker Corp., Fort Wayne, Ind. ° ° Besides, shaved gears marks are more nearly line with the rolling and sliding action the teeth, whereas grinding marks are directly across the face the tooth. Limitations Cited the many discussions the sub- ject shaving versus grinding aircraft engine gears that have taken place meetings the Aircraft En- gine Division the Automotive Coun- cil for War Production (now known the Central Aircraft Council), the general approach the basic problem distortion the gear result hardening has been concentrate design press quench fixtures prevent such Here Fort Wayne, the opposite stand taken, namely that gear such design that has press quenched (and there are dozens quench presses this big plant), uneconomical finish the gear shaving the green state. Such gears logically should ground. press quenched, much added ac- curacy needed the machining holding and locating sections which are otherwise not critical that any savings cost finishing over grind- ing are offset refinements ma- chining the blank. the surfaces gripped the press are not accurate- machined, there likelihood that the press pressure itself will cause distortion. gear with thin web section and offset hub typical one that should finished grinding rather than shaving. Quenching stresses are bound cause the web act bellows and cause displacement the hub with respect the gear teeth and change pitch diameter will occur along with other distortions. The limitations recited above rather the field application shaving aircraft gears, and only natural that the first gear this plant should represent the ideal Since press quenching was ruled out the start, there was only one Fort sub- taken En- Coun- nown the oblem result itrate such press t), Such sfully ac- which any ma- faces that cause and that ather teeth will ather ideal ruled one alternative solving the problem distortion, namely: Coordinate all the volved, such selection steel, forging, stabilization structure, machining heat treatment, that the distortion hardening consistent and there- fore can anticipated modifi- eation tooth form. The best way illustrate how this accomplished will describe the step-by-step processes manufac- turing the 15-tooth planetary pinion, which now being shaved 100 per cent. the Wright engine, these pinions are mounted spider and float between 135-tooth internal bull gear, which has shaped and lap- ped teeth and 105-tooth gear which hobbed, ground and lapped. The large number pinions involved rep- resents ideal example from the point view production quantities. Consistent Distortion Sought The success shaving this car- burized pinion due the fact that although distortion heat treat does gear that can anticipated modifying the tooth the shaving cutter and deliberately cutting gear with tooth profile that varies from the true involute. When hardened, the tips the teeth tend move out and the involute falls off the tip the tooth. for this distortion that modifications are made shav- ing the teeth. contributing factor the the job obviously the form the pinion. the sec- tional views, Figs. and indicate, the thickness the rim the bottom tooth space very nearly equal the chordal tooth thickness the pitch line. always advantage controlling hardening distortion have only minor inequalities sec- tions. The material from which the pinion blank forged AMS 6250 (SAE 3312) having per cent nickel, per cent chromium and 0.08 0.13 per cent carbon. electric fur- nace steel suitable for carburizing light sections. Although supplied four five steel mills and forged several subcontractors, which results obvious variations heats, there good consistency the distortion these pinions the final hardening process. This partially attributed the fact that the material brought uniform microstructure the normalizing and annealing First Normalized When the forgings enter the plant they are visually inspected, and are 2—Enlarged cross-section the pinion shown Fig. formity section big factor controlling distortion hardening. then heat treated give uniform structure for machining. They are then normalized 1725 deg. for hr. min. heat, this tempera- ture being deg. above the subse- quent carburizing temperature. An- nealing takes place 1050 deg. F., slightly varied with different heats, but before entering this zone the furnace the forgings are cooled 500 deg. the cooling zone with the aid circulating fan blowing air over cooling coils and directed against the work baffle plates. After anneal- ing, the forgings cool vestibule See also “Relationship between Micro- structure and Norman Woldman, Tue Ace, June and June 26, 1941; also “Machinability vs. Microstructure Gear Steels”, Ace, Nev. 1941. 350 deg. and finally air. This produces partially spheroi- dized structure sorbite and globu- lar carbides matrix ferrite and hardness 210-250 Brinell. effort made keep the hardness the high side and obtain well dispersed structure order facil- itate obtaining good finish gear cutting operations. Ferrite which normally present large proportions low carbon steels gummy constituent which tends ball the tool and produce tears the work. After heat treatment, ° ° 3—The protuberance placed the hob teeth serves blend the root radius into the involute, since the shaving cutter does not get down into the root the gear teeth. Protuberarice Rad the machinability these forgings about 40-50 per cent SAE 1120. The normalizing and annealing fur- nace electrically heated pusher type furnace with non-scaling atmos- phere made cracking natural gas and mixing with air the ration 1:6. The machining operations the blank consist drilling the hole the blank and rough and finish broach- ing size, then chamfering and turning the o.d. and facing both ends, finally grinding both faces minimize errors when mounting the blanks multiple the hobber arbor. Before hobbing the hole packed and the blanks copper plated protect those areas which are remain soft. Hobbing Modifications was the hobbing that the first modifications procedure were made changing over from ground pin- ion shaved pinion. order strengthen the tooth and control the blending the root radius the in- volute, since the former not touched the shaving cutter, was neces- sary resort protuberance hob. Modification the rack form shown Fig. The hob size also was changed from in. in. diam- eter and more gashes put pro- duce smoother root. And because little correction form possible the shaving operation, Class hobs are employed, ground with radial re- lief. These hobs have tapered holes assure concentric fit the ma- chine arbor and minimize runout. get improved surface finish the teeth, the hob has been reduced from 0.050 in. per rev. 0.025 in. and “climb cutting” used eliminate the susceptibility tears mentioned previously being due the large amount free ferrite present this steel. Halving the feed necessitates the use per cent more hobbers, but this increase minor compared the reduction grinders com- pared with shaving machines. climb cutting the direction hob ro- tation remains the same conven- tional hobbing, but the feed re- versed, being away from the head- stock rather than toward it. Hob feed proceeds from left right and each hob tooth takes deep bite the start the cut. Four blanks are which Barber-Colman horizontal type. Sinclair Carnite base oil inated-sulphurized fatty oil) mixed the ratio 1.3 with 82-see. Say- bolt paraffin oil coolant, the re- sulting mixture viscosity being 200- sec. 100 deg. THE IRON AGE, December 16, 1943—45 4 ” Q/76 min. | tool with the are tooth. q 7 Burring the ends the teeth follows hobbing, then the gears are put the National Broach shavers. One man tends two these Red Ring gear finishers, which there are four, and each machine has output pinions per hr. net floor-to-floor time min. This compares with grinding time min. for three blanks the arbor min. each. Formerly grinding machines were assigned this pin- ion job. the current expansion program, these are being set aside for other work not suitable for shaving. Again Carnite base oil mixed 1:3 with paraffin oil used coolant for the shaving operation. Specifications the rotary shaving cutters are: No. teeth Helix angle deg. R.H. Diametral pitch 10.36 Pressure angle deg. Chordal tooth in. Cutter cost Cutter life 5000 pinions per grind and has five usages to- tal 25,000 pieces. The cutters are returned the factory for resharp- ening certain modifications tooth form are necessary correct for heat-treating distortion (compare Figs. and 5). should men- tioned that the machines are set in. the teeth aid centralizing the tooth bearing area. Rotary type cutters operating the cross-axis principle (10 deg. this example) are preferred for straight spur gear finishing. Rack type cutters, which were first introduced automotive gear finishing practice, are preferred for helical gears, which are seldom encountered aircraft engine pro- duction. The finish obtained shaving excellent, being about for grinding. Only small amount metal removed—0.008 in. over p.d. pins, about 0.00175 0.0020 in. the involute flank. 4—Typical chart taken from involute tester, showing the deliberate distortion the involute made shaving the teeth the pinion illustrated Fig. Each curve for different tooth the pinion. ° ° 5—Involute test after hardening the same pinion charted Fig. Note how the involute has been pulled back into line controlled distortion. IRON AGE, December 16, 1943 0.0004 type mple) gear which notive ferred ing mount 0.0020 showing teeth charted nto line After being inspected greased, the pinions are ready for Much the success the shaving process from this point trol. indicated earlier, what be- ing sought not elimination heat- treat distortion, but control predictable amount. Carburizing the first place should noted that carburizing takes place after shaving rather than before. This choice was made avoid back track- ing handling parts and out the heat-treating sides, carburizing not the critical treatment much the hardening. Natural gas used the carbu- rizing medium and the depth case sought 0.032 0.036 in. There are 12.2 sq. in. per piece carburize and this governs the flow natural gas, which cu. ft. per hr. for Leeds and Northrup Homocarb. The finished pinions are loaded circular trays, three layers tray and the load five trays high for insertion Homo pot-type electric furnaces. Furnace 1200 deg. when charged and slowly brought 1700 deg. and held there until 0.032 in. case formed, which takes about hr. Notched test bars which ac- company the work-are pulled out the furnace and examined for depth case the end hr., hr. and the end point. Then the furnace temperature dropped 1500 deg. and the gas flow increased for hr., during which time the total carbon penetration increased approximately 0.003 in. and the outer zone the case enriched carbon. soot deposit deliber- ately created during this period order prevent decarburization dur- ing the transfer and while the pin- ions are the covered cooling pit. Here the work allowed cool slowly gaseous atmosphere for about hr., which time the tem- perature has dropped 450 deg. Fur- ther cooling room temperature takes place outside the pit. Soot removed shot blast Pang- born Rotoblast table type machine. The pieces are run through three times assure cleanliness. “insurance policy” pre- vent possible decarburizing during hardening, the pinions are copper plated 0.0005 0.0008 in. all over. Hardening done roller rail type furnace made the Electric Furnace Co. The pinions are loaded trays, per layer, two layers high and every min. two trays are 6—Microstructure pinion gear normalized 1725-1750 deg. and an- nealed 1060 deg. prior hobbing and shaving. The structure reveals the presence sorbite and partially spheroidized carbides with matrix ferrite. (1500 x.) pushed out the furnace into the hydraulic elevator quench, the total furnace cycle being hr. The initial zone 1420 deg. and the remain- ing three zones 1485 deg. Cracked gas mixed with small percentage natural gas serves protective atmosphere. Quench time min., the quenching medium being 82-sec. Saybolt paraffin oil. complete the transformation the austenite martensite and hence stabilize the structure, the gears are given sub-zero treatment —60 deg. Initially dry ice was used for this purpose until mechani- cal equipment (Kold-Hold) with ac- curate temperature control could installed. This was being readied for use the time writing this article. One hour the cold treatment sufficient increase the hardness quenched from Rockwell 66-68 Subsequent drawing for hr. 325-350 deg. Homo pot fur- nace reduces this hardness 61-63 Rockwell Drawing the Homos followed shot blasting, then inspection in- cluding complete distortion check pinions out every lot 1000, which the furnace charge. This means that the same pinions, prop- erly identified, are also completely checked the green state following shaving. The Illinois involute form tester gives the best check con- trolled distortion. comparison Figs. and which are reproduc- tions typical charts produced this instrument, shows the deliberate involute form errors introduced the teeth the shaving process and the correction obtained during heat treat. the green gears, Fig. for example, there uniform varia- tion about 0.0010 0.0013 in. from the bottom the working face the tep. The same gears tested for in- volute form after heat treatment, Fig. shows variations 0.0004 0.0007 in., well within the tolerance 0.0010 in. involute forms. addition, the usual measure- ments pitch diameter, backlash, runout, are made but the graphi- cal record involute form the ba- sic control point the coordination machining and heat-treating opera- tions just described. The results are adequate proof the soundness the decision shave rather than grind these pinions. number operations remain complete these parts. The hole must finish ground while chucked its pitch diameter and its edges radiused, then the two faces finish ground and finally microfinished and buffed, since they serve end thrust surfaces. The teeth surfaces are Tampico brushed. Finally the hole lapped size before the pinions are given 100 per cent inspection. Considering its simple geometric shape, this piece has extremely large number operations bring its final state perfection. In- cluding inspections, there are less than operations, which shaving just one, but big enough one form the basis this article. THE IRON AGE, December { and pipes are needed carrying out the ever-expanding program for the construction more ships, more tanks, more planes and those hundreds other imple- ments war which not possible enumerate their entirety. There hardly any other structural element greater importance for the prose- cution the war well for peaceful pursuits. Just few examples may men- tioned: More and more tubular ele- ments are being used airplane frames. This done not only ac- count the high weight-strength ratio tubes compared with that open rolled sections but also for the reason that tubular strut, when hit pierced bullet, will frequently lose less its original strength than open section the same circum- stances. Moreover, larger percen- tage bullets than otherwise will diverted and slip off upon hitting tubular element, particularly one hav- ing streamlined shape. Ehrhardt and Sehmer Piercing process among the peaceful will just mention the pipeline. Every civilian’s life and pursuits are now being badly affected because adequate pipeline net was not laid time. fact, its construction has until recently met with strong oppo- sition. good thing that now, route along which many the pioneers ventured forth Texas, the oils flow east 24-in. pipe, the “Big Inch,” forwarding million gal. oil day. Inventors and Inventions view the extraordinary im- portance tubular products have won seems timely review both the great inventions made the manu- facture tubes and certain develop- ments that took place this field. The basic principles the art have not greatly changed recent decades. Yet the improvements the industry has carried out and the variety uses which its products have been put are simply admirable. A-A B-B manufacturing processes which tubes and pipes are made. The one starts from long flat strips metal, called skelp, from flat plates. The other process starts from solid billets. third process, cupping, almost abandoned before the war but has recently gained new importance the making steel shell cases. Beginning the description these processes with the piercing process, must said that this one the greatest inventions and represents one the most amazing operations the shaping steel. The writer will, however, confine himself more less discussing the development this invention Europe which has more intimate knowledge. two The invention the seamless tube furnishes excellent example how new processes frequently develop. proves the fact that the perfection such process rarely being accom- plished one single mind. Certain technical developments will come Section Section Section Section Section Section F-F Section D-D ABOVE solid billet diagonal rolling. LEFT the early piercing process supposedly developed the German firm Ehrhardt Sehmer, square billet was heated high forging temperature and then placed round die block. cylindrical piercer (a) (b) sufficient diameter force the displaced material into the four spaces be- Pierced tween the billet and mold was driven into the billet. The tube was further processed inserting slightly conical mandrel into the shell and pushing billet billet both through series ring shaped dies decreasing diameters. 48—THE IRON AGE, December 1943 Sl m 0 two one etal, The llets. been but ance the one the will, this has tube how com- rtain erman orging cer ushing point maturity when possible re- sults may anticipated, inventive minds different places and countries will then, about the same time, feel induced work toward, and achieve, the very same objective. successful process will thas rather the result series developed ideas than that single invention. The steel industry furnishes most striking ex- amples this kind: The bessemer process was developed two men absolutely independent other, one was American birth the name William Kelly, the other Englishman, Sir Harry Bes- semer. the early eighties, Stiefel, American, and the Mannesmann brothers Germany attempted re- place the tedious and costly processes boring hot piercing billets presses through continuous rolling process. is, generally agreed that the priority for this in- vention belongs the Mannesmann brothers who were granted patents Industry ° ° ° DR. BERNARD PLANNER ° have brought tubes and tubular products prominently into the fore- ground. this the first three-part article the evolution present day practice, the Mannesmann process rolling hot steel bars produce cavities and the inventions the barrel type pierc- ing and disk rolling mills are discussed. early 1885. Soon after, around 1890, number heated patent dis- putes were fought out the courts between Stiefel and the Mannesmanns. was established that American workers were major degree en- titled credit for faster mechani- cal perfection the invention. the end, often the case, many manufacturers availed themselves the advantages both these proc- esses, the Stiefel type and the Mannes- mann barrel roll type, whichever was ABOVE 3—This one stand, barrel type, piercing mo- chine A-machine had rolls about diameter and in. long. Cylindrical chocks fitted for the roller bearings could moved axially thereby changing the space between the rolls. RIGHT IG. 4—Later model the A-machine built 1887. Feed was through the side the drive and cogged cylinders were used. improve the cavity formed, piercing point was used. Billets about long and in. diameter could pierced this machine. best suited the kind work re. The Mannesmann Process First the attempt was made apply iron and steel the extruding process which means hydrau- lic pressure hot metal forced through orifice, method perfectly suitable for the comparatively soft non-ferrous metals. For the extrusion steel, however, this basically simple process requires enormous forces and results terrific wear material. For this reason the process even now hardly beyond the experimenta! stage. Another method was simply drill out solid billets. This was the way which some the old musket barrels were Yet another early invention, which until not long ago was successfully employed, was piercing method ascribed the German firm Ehr- hardt Sehmer. their process the billet was heated high forging temperature. The the square billet then took place within round die block means driving THE IRON AGE, December 16, | be Q SSN cylindrical piercer ram into the billet. (See Fig. 1.) The piercer had diameter appropriate displace the material just fill the four in- termediate spaces formed between the original billet and the mold. Further processing took place the insertion slightly conical mandrel into the shell and pushing both through series ring shaped dies smaller and smaller diameter. the Mannesmann process, this was based entirely novel and revolutionary idea and rather in- teresting see how the inventors con- ceived it. For three generations the Mannes- mann family had been operating well-known file factory Remscheid, city, which together with Solingen, another German city, was the now frequently mentioned birthplace the German tool steel and tool industry. The Mannesmanns used part their own self-made crucible steel. Files were then cut hand which required highly-skilled craftsmanship. The spe- cial tool steel requisite for this manu- facture was the time partly im- ported from Sheffield, England, the form round bars and shafts. These round bars were polished England so-called reeling machines. The feeding, sizing and polishing the bars was accomplished means barrel-shaped rolls, parallel the vertical plane but angular position the horizontal plane, giving the bars rotary motion and pushing them forward the same time. When cut broken the required lengths these bars showed radial fis- sures issuing from the center. Some- times the center bar even showed aperture. Both the British manu- facturers and the German customers felt worried about such defects the IRON AGE, December 16, 1943 5—Until about 1890, was thought that the shape the rolls determined the type cavity formed. Therefore nu- merous roll shapes were tried. Here three types piercing rolls used between 1884-90 are illustrated. material, but there was satisfac- tory explanation for this phenomenon which was apparent certain kinds forgings. Two the Mannesmann brothers, who were credited with many inven- tions various other fields, had the idea reel, roll, hot steel bars diagonally order create cavities intentionally which, until then, had come about accidentally. their in- vention piercing solid billet chine was fair- tion, having four cyl- indrical chocks one stand, two carrying bearings for the rolls and two guiding ele- ments. IS. ‘> a q ‘ Driven working diagonal rolling (as detailed Fig, was not matter accident but the achievement what they had long been looking forward and what the rolling mill engineers the period had deemed impossible. this stance seems proper state that cavity although uneven and irregu- lar may produced within solid billet without the use mandrel, called piercing point, Without belittling the merits this invention must recorded that the inventors were unable explain sat- isfactorily why the cavity formed, Many and very contradictory theories the subject were later developed. reviewing this outstanding inven- tion and justly evaluating its merits must borne mind that 1885 the sciences metallography and metallurgy were virtually non-exis- tent. Furnaces were rather primitive and were temperature measuring methods. The billets had brought high forging temperature and were kneaded such The pressure which the billets were subjected this process was great that the pierced billet would emerge with temperature that was some- what higher than the entering tem- perature. All these complex processes and all those characteristic features steel that may summed the term “pierceability” have not yet been clarified. Little wonder, therefore, that for long time the inventors were denied any success and that, their efforts develop their invention commer- cially, they lost their quite substantial BELOW 7—The I-machine the conven- tional two-mill construction with adjust- able rolls. q a a a Fig, but long hat the period his in- that irregu- this hat the formed, loped. inven- merits 1885 and on-exis- asuring and were great emerge rocesses not for denied efforts stantial conven- adjust- for the adjustment inclination 8—Diagram assets. Until 1900, and even there- after, the production seamless tubes was expensive that notwithstanding the general recognition its im- portance could not undertaken profitable proposition. pursuit their basic invention the inventors made the object their further experiments find the most suitable contour for the working rolls, the optimum angle thereof, and general master mechanically the novel and intricate problems created this type rolling. Barrel Type Piercing Mills The first piercing mill, called machine, which was covered Ger- man patent, DRP 34617, 1885, illustrated Fig. was one- stand mill with three working rolls. Experiments with this mill were al- ready made 1884, without the use mandrel piercing point. The rolls had diameter approxi- mately in. and were in. long. The chocks fitted for the roller bearings were cylindrical and could moved the axial direction narrow widen the space between the rolls, well around their axis allowing the adjustment the inclination the rolls. Another A-machine built 1887, shown Fig. Here the feeding took place the side the drive and cogged cylinders were now employed. was with this machine that was first attempted employ piercing point smooth and round out the cavity. Billets approximately ft. long and in. diameter were thus pierced. Because the lack knowledge the L-machine. the influence the composition the steel, and its metallurgy, the formation cavities the shape the rolls was deemed paramount im- portance. Between 1884 and 1890, hundreds upon hundreds different roll shapes were tried out this ap- paratus. Frequently shown Fig. were provided with swellings. addition, threads varying angles and forms were cut hand into the surface the rolls the belief that the impression the respective forms and directions the threads into the billet stock would accelerate retard the move- ment the material. Eventually became possible make tubu- lar shells from Swed- ish steel, approximate- in. o.d., that could Schematic view the D-Type barrel piercing mill. cold drawn into gun barrels. Yet the attempt make longer tubes met with tremendous difficulties. Since the piercer could not sustain the in- creasing pressure bent and the re- sult was irregular tubes and con- siderable amount-of scrap. Attempts make the piercer rods the hard- est material available and ceol them after every act piercing brought hardly any improvement. Difficulties such kind brought about another important invention, the so- Pilger step process which will discussed later. The next step the development, however, was the G-machine (Fig. 6). sturdier construction than its pred- ecessor had four cylindrical chocks mounted one stand. Two them earried the bearings for the rolls, an- other two the guiding elements. For the rest, the diagram self-explana- tory. The construction the I-machine (Fig. brought further improve- ment. With this machine the inven- tors took the conventional two- stand mill construction which ordi- narily employed rolling mills. This construction was also based the realization that the inclination the rolls could less than had until then been deemed necessary and, above all, that for certain working range could left unchanged. be- came possible simplify the whole construction. The necks the rolls THE IRON AGE, December SCHEMATIC PRESENTATION THE VARIATION THE OBLIQUITY Stationary Turntable Inclination=0 Driven working rolls Worm gear for the adjustment the were arranged that they rested in- dependently and could adjusted the sturdily constructed stands with the chocks fixed between straight guid- ing planes. This construction has been adopted the basis for modern piercing mills this type. the same time, the L-Machine (Fig. 8), D-machine (Fig. and machine (Fig. 10) were developed. The C-Machine represents. inter- esting kinematic solution the eccen- tric adjustability the rolls. They stands, one stand fixed and the other segment that the de- sired inclination the rolls could obtained. For obvious reasons this construction was too delicate ser- viceable for the heavy requirements rolling mill. Cone Disk Type Mills The first disk type rolling mill was one under the German patent, DRP 34617, 1885. was claimed that the disk type rolls offered definite ad- vantages over the barrel type rolls. Actually, disk type rolls have been used almost exclusively for the expan- sion billets already pierced, that enlarge their diameters and make their walls still thinner and more regular. view the increasing tendency longer piercer rods bend under the pressure applied, the idea was first pierce short lengths rough tubes barrel type piercer and then enlarge, smooth and possibly ‘lengthen them disk type mills that the pressure the piercer rod was reduced during the latter opera- 52—THE IRON AGE, December 16, 1943 Stationary Changed inclination 10—The rolls the C-machine were supported two rate stands, one fixed and the other movable the rolls could Turntable clined. Lower Device reduce and widen the distance between the tion. Due the lack metallurgical knowledge and the non-existence suitable furnaces, however, this idea did not materialize. mill this design built 1888 shown Fig. 11. The eccentricity the two bearings was adjustable. The center line the rolls formed angle facilitate the entry the tubes. the sources power were the rather weak and but little the greatly varying power ments during the rolling operation proved necessary run the machine highest speed and store the power two heavy flywheels the billets were put in. When due the sudden subjection stresses too rapid rotation, some these wheels burst, another flywheel invented whose rim was coiled with wire. (See Fig. 12.) Many mills such type have since been structed. more complex construction, dated 1890, shown Fig. 19. The axes the disk rolls rested two chocks mounted two cast iron stands could turned around the center circular bed plate allow ad- type mill built 1888, Eccentricity the bearings was adjustable and the center line the rolls formed angle facilitote entry the tubes with rim justment the angle the rolls cording requirements. Such adjus- tability, turn, required flexible bear- ings and other complicated structural details which can partly recognized Fig. 13. Piercer points varying shapes and contours were tried out this mill try make the walls the tube still thinner and uniform ° 12—Flywheel built around 1890 with wire coiled around rim prevent breakage when rapidly vere require. machine the before due resses these fiy. heel with mills een on, dated axes chocks which allow ad- type the and the the facilitate the tubes, rolls adjus- ble bear- cognized shapes this the iform ent possible and, simultaneously, en- large its diameter. One the reasons for the many failures the time was the lack suitable furnaces and the inability heat the stock uniformly the re- quired temperature. Again and again the furnaces were rebuilt. And there was still the old trouble the bending the piercer rods overcome, particularly the longer ones; other words, the difficulty centering the piercing point accurate- had still met. Failures and inabilities this kind eventually com- 13—Complex disk mill built 1890. The rolls could adjusted any angle. pelled the inventors set aside this process that time. was much later that one reverted this process. This was upon the first successful piercing operation means the Pilger step process, and after the piercing point had been mounted—as kind third, internal roll—on hanging piercer rod, which was only exposed tension stresses, thus replacing supporting rod ex- posed compression and bending. This improved moved the main source all difficul- ties. similar disk type mill illus- trated Fig. 35, now employed the largest, up-to-date, tube expansion mills turning out pipes in. diameter. Ed. Note: Next week the invention the Pilger step mill and its subsequent improvements well welding and shaping procedures are described. Effect Lead Manganese-Molybdenum Steel COMPREHENSIVE study ma- terial from two ingots man- ganese-molybdenum steel, one which 0.19 per cent lead was added, was recently completed Swin- den, United Steel Co.’s, Ltd., Stocks- bridge, England, and presented the British Iron and Steel Institute. The leaded steel had slightly coarser inherent grain size and less depth hardenability than the non-lead- steel, indicated the chart Jominy end quench results, shown the accompanying graph. The prop- erties measured the tensile test room temperature were similar for the two steels the form flat and round bars. The notched-bar impact toughness the leaded steel room temperature was rather less than that the non-leaded steel. elevated temperatures, the max- imum-stress values both steels were similar, but the ductility, measured elongation and reduction area, was lower the case the leaded steel, particularly the transverse direction. The Izod impact values the leaded steel also were lower elevated temperatures. The Barr-Blodgett creep-stress val- ues the two steels 930 deg. were identical, while difference was shown the figures for damping capacity. When treated tensile strength tons per sq. in., the fatigue ratio and notch sensitivity (rotary bend- ing) the two steels were similar. When treated the lower tensile strength about tons per sq. in., the non-leaded steel had higher fatigue ratio (rotating cantilever) and slightly greater notch sensitivity than OMINY end- ability test results leaded (0.19 per [=] cent) and non-lead- manganese- mo- lybdenum steel, nor- malized 1580 deg. and quenched Vickers diamond hardness al the leaded stee