The Iron Age 1943-05-20: Vol 151 Iss 20

¥ ELE War production requirements have given great stimulus improvements machine design. This trend not only affects fighting equipment, but also every kind industrial machine. will become even more pronounced during the reconstruction period following Victory. why will pay you—right now—to redesign your product include Timken Bearings every possible point. doing you will help the war effort; and furthermore you will all prepared for the competitive post-war period with better performing and better selling product. “Timken Bearing Equipped” assures superiority equipment buyers everywhere. THE TIMKEN ROLLER BEARING COMPANY, CANTON, OHIO 3 | | Vice-Pr News Technic Our Alloy-502 (35-15) available cast rolled form. offer design suggestions its use; and the metai always sound. Was Cle heat recommended for its cleanliness, quietness, and range; plus the ease applying it. These are among the reasons why like Hoskins A. H. Electric Furnaces. Also, they lik the tough durability the Chromel heating units, and their ease renewal. The furnaces are made box and pot types, several sizes. The box furnaces handle parts per hour 1500° The and will melt 500 Ibs. Member M b make brazing furnace that 10 takes little space and does good job fast, economical brazing. Catalog describes them. Hoskins Manufacturing Company, Detroit, Michigan. Chestnut Phila: JOS. SEORG EVERIT THE IRON AGE, published every Thursday the CHILTON CO. (INC.). Entered second class matter November 1932, the Post Philadelphia under act March 1879. yearly North America and South America, Foreign $15. Vol. 151, No. 20. MAY 20, 1943 VOL. NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager News Markets Editor, JAMES Technical Editor, OLIVER Art Editor, WINTERS Associate Editors Editorial Assistants BUTTERS Regional News and Technical Editors Washington Pittsburgh Washington Chicago Cleveland Detroit OSGOOD MURDOCK San Francisco Editorial Correspondents Buffalo Cincinnati FRAZAR RAYMOND KAY Boston Los Angeles HUGH SHARP JOHN McCUNE Milwaukee Birmingham SANDERSON ROY EDMONDS Torento, Ontario St. Louis BACON Seattle ° ° ° DIX, Manager, Reader Service ° ° ° Regional Business Managers Robert Blair, 621 Union Bldg., Cleveland Fitzgerald, 428 Park Pittsburgh Herman, Chilton Bldg., Philadelphia Hottenstein, Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd New York Johnson, Market Research Mar. Hayes, Production Manager. Baur, Typography and Layout. Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. lished every Thursday. Subscription Price North America, South America and Possessions, $8: Foreign, year. Single Copy, cents, Annual Number, Cable Address Y." ° ° ° Owned and Published CHILTON COMPANY Executive Editorial and Advertising Offices 100 East 42nd St. New York, U.S.A. Offices Chestnut and Sts. Philadelphia, Pa. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, GRIFFITHS, EVERIT TERHUNE, VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY CHARLES HEALE Vice-President Vice-President Vice-President This Week in... Editorial Technical Articles Transfer Molding Thermosetting Conserving Rubber Industrial Truck Tires.......... Mass Production with A.C. Welding........ Low Expansion Alloy Made Free Masking with Cellulose Airplane Fuselage Stringers......................... Centrifuging After Filling the Cleaning Gas Welding and Cutting Carbide Tips Automatically New Equipment: Plant Service Features News and Markets This Industrial Iron and Steel Scrap Finished Steel 165 Copyright, 1943, by Chilton Company (Ine.) : JHE IRON — 44—THE IRON AGE, May 20, 1943 FOR QUICK ACTION STEEL ee E’RE having better luck steel, said manufacturer the other day. were times when had and but now are going the warehouse with the most com- plete stocks, with best facilities for handling and delivery. are saving the time shopping around—and saving man-hours our plant—by calling Ryerson first.” Sound reasoning, isn’t it, when you want some- thing, where you’re most apt get it. Whether it’s fast service, steady, reliable source, cutting fabricating operation that will facili- tate your production, assist- ance, you’re most apt get what you want calling Ryerson first! Ryerson has maintained its leadership the steel business making good every promise, knowing the kind service customers want and giving them, and above all else, having stock most the time the kinds, shapes and sizes steel they want, ready for immediate delivery. Stocks are reasonably complete, considering the war demand placed upon them. But, whatever kind steel you want, within the plan; what- ever service you would like have, Ryerson first! get intelligent cooperation— Ryerson! JOSEPH RYERSON SON, Inc., Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City | ° ° MAY 20, 1943 ° ° ESTABLISHED 1855 Our Part Selective Service Occupational Bulletin No. 43, issued the War Manpower Commission, which lists scientific and technical journals specifically under activity No. 35. Unless industry classified essential war production goes “all deliver the maximum possible effort toward helping win the war, not living the responsibility imposed upon it. per cent job won't do. You who read THE IRON AGE who advertise and who are turning out munitions war and other essentials astonishing quan- tities not consider that just doing this satisfies the requirements placed upon you. For addition and equally important our eventual victory the obligation conserve critical materials. The idea might summarized as: Maximum production plus maxi- mum conservation. You have found that these two are not incompatible. practice conservation, you have adopted expedients which would not required peacetime economy. dealing with the quality factor you have eliminated the from your product. You have made serviceability the criterion and relegated finish and appearance second place. Even though you may eligible command critical materials because your priority ratings you have endeavored sub- stitute, wherever possible, other non-critical materials your products and operations, knowing that wherever you you are multiplying the effectiveness the war effort making less farther and more. You are the barrel” recover scrap and pass along double duty. You would ashamed use one unnecessary pound scarce metals other substances your product, knowing that you did your conscience would label you “slacker.” THE IRON AGE also have this double responsibility maximum production plus maximum conservation. Our products are ideas and information which pass 11,437 plants and over 100,000 readers help them turn produce more and conserve more. The critical material going into our products paper. Paper necessary the war effort steel aluminum copper. believe that any publisher who now uses pound more this vital war material than necessary for clearly transmitting ideas not living his war responsibilities. Thus, from now until Victory Day shall practice conservation with respect paper the limit consistent with maintaining and improving the editorial services and serving our expanding industry. accom- plish this have reduced the weight our paper stock and will reduce still further this found practical. Finish and frills are out with too for the duration. believe that you will agree with this policy and that you will also agree that this issue that you are reading fully lives the service- ability standard that have established over the years. : | | | | | | | | Berlin Harold Gibson (left) for the duration Miller, Gen. Supt. Good Hunting, Harold! Harold Gibson going hunting—hunting down the tyrants who seek destory our freedom. Inland’s 3000th man join the Armed Forces, and they continue leave the rate 200 per month. Several years ago, Harold started work laborer the Inland mills. Unhampered tradition, class living the Four Freedoms—he advanced crane operator the No. Open Hearth yard. That the American which free men choose time, place and type work, and win advancement through ambition and ability. Even with more than 25% placements since the war began, our average has been maintained more than 100% capacity. So, Inland steelmakers, 14,000 strong, say, “Good hunt- ing, Harold,” and back him and the others with Bonds, sweat and steel. INLAND STEEL COMPANY CHICAGO 46—THE IRON AGE, May 20, 1943 ment the ess injectior material injectior material cause chosen ess, Fra tinued The pher were original tion molding ber was tion ing mat duced Hand were sembled with and the the app This ver Multi order were on, the rates velopme Matic 1915 ment ° ° ° NORRIS Service Engineer, Bakelite Corp. the outstanding develop- ments that has played such prominent part the advance- ment the art plastic molding the transfer method molding thermosetting materials. This proc- ess also frequently referred injection molding thermosetting materials (not confused with injection molding. thermoplastic materials like cellulose acetate). Be- cause the term transfer molding was chesen the originator the proc- ess, Frank Shaw, its use will con- tinued here. The first molded pieces made phenolic thermosetting materials were produced molds that had originally been built for the produc- tion hard rubber parts used for electrical insulation. result, the molding practice used for hard rub- ber was also applied the fabrica- tion thermosetting mold- ing material when was first intro- dueed Dr. Baekeland 1907. Hand molds the compression type were employed. The molds were as- sembled the molder’s bench, filled with weighted amount material and then placed hand com- paratively small hydraulic press for the applications heat and pressure. This meant that the molding process Was very slow. Multiple cavity molds were used order increase production, but they were still hand molds. time went on, the need for higher production rates and lower costs led the de- velopment the so-called semi-auto- matic press. This took place about 1915 and was the first real advance- ment the technique plastic mold- ing. the semi-automatic set-up, Although the process transfer molding phenolic compounds was first developed the Shaw Insulator Co. 1926, complete description the technique and its application have just recently been revealed. This abstract paper presented January before the Society the Plastics Industry Toronto the upper and lower portions the mold are rigidly fastened the top and bottom parts the press, thus eliminating the necessity for the op- erator handle the mold manually. Large multiple cavity molds could used and press capacities were con- siderably increased. Some years later the Shaw Insula- tor Co. Irvington, J., was at- tempting mold firing pins for the Navy. This piece consisted steel insert about in. long encased shell phenolic molding mate- rial. Then now, the dimensions were rather “fussy.” This piece shown Fig. Attempts were made produce first assembly produced trans- fer molding was this firing pin for the sists steel insert encased phen- molding com- pound. this part compression molding. The insert was placed vertical posi- tion the mold because the high and unbalanced pressure exerted upon might cause distortion were hori- zontal and the use split mold would undoubtedly cause the parts out round. While the elimina- tion split mold took care ec- centricity did not overcome the dis- tortion the insert. First Applied 1926 was then that Frank Shaw con- ceived the idea placing the insert the mold and closing the mold empty, and then “transfer” the mold- ing material plastic state into THE IRON AGE, May 20, 1943—47 ranster | as £ | the cavities through openings gates transfer molding was born. This took place the early part 1926. The date significant when remem- 2—Use the transfer process eliminated the the raised bered that thermoplastic materials numerals and graduations the die for this business machine scale. mold and injection molding machines were cils not general use prior 1930. The results obtained the firing only job through the use transfer mold- quire tion another part, this time for different reason. The long narrow hand produced for one the business ma- face and back series gradua- built. tions together with numerals. These molded piece, which were filled proxi 3—Core pin distortion the production slender parts like automatic pencils with white paint. The corresponding avoided transfer molding. raised sections the mold were con- tinually being damaged and “washed off” the action the molding ma- terial when the parts were produced order pair costs ran high and order overcome this condition was de- barrels, heretofore stubborn prob- lem which challenged the ingenuity porat the young plastics industry. low the tricks compression molding the tried, but still the comparatively and slender core pins would bend might with the resulting non-uniformity not wall thickness. theles the transfer method molding, ence high and unbalanced initial pressures has were minimized because the material some was brought soft plastic state before entering the mold cavity. Thus, core pin distortion was longer major problem. the Experience gained here was readily adapted the molding pencils (shown Fig. which were turned out the millions. These pencils that are the propel and repel type corpo which the lead may advanced ABOVE retracted means helical thread running the entire length the bar- possibilities the transfer mold- tiple cavity mold using two rectangu- ing process. lar pressure pots. This arrangement was chosen order obtain equal sulate distribution material over the en- tire length the mold and the from same time provide ample pressure prove LEFT chamber area. “electric eye." the design transfer molds, thiek the area the pressure chamber 48—THE IRON AGE, May 20, 1943 | least 15-20 per cent greater than the projected area the cavities. Thus the pressure exerted the mold, tending keep closed, all times greater than that developed within the cavities trying push the mold open. the case these pen- cils, there was hardly any flash along the parting lines the mold. The only finishing operation that was re- quired was performed the molder. simply took handful the molded pencil barrels them together the palms his hands, and the job was finished. order investigate further the possibilities transfer molding, number experimental molds were built. Some the pieces produced these molds are shown Fig. The cylindrical shaped objects are ap- proximately in. diameter with over-all length about in. These are hollow with closed ends, except for hole about in. diam- eter. Sections have been removed order show internal details such as: rib projecting into the hollow inside portion, but not coming through outside wall. lining thin copper foil about 0.003 in. thick molded the inside wall the hollow cylinder. porated project into the hol- low cavity, but not extend through the sides the piece. While true that these parts might classed “trick pieces” and not commercial applications, never- theless the information and experi- ence gained through producing them has proved invaluable solving some the more difficult problems presented industry. For instance, the electric eye shown Fig. important feature the glass window the front the piece. From the experimental work carried with the glass ribs the hollow cylinders, was learned that glass could successfully in- corporated into molded object when method molding. Molding Foil Inserts Again, when manufacturer electrical instruments wished in- sulate complicated and delicate cop- per insert, the knowledge obtained from experimenting with copper foil proved very valuable. The in- sert and molded piece are shown Fig. The copper from which this insert constructed 0.010 in. thickness. Before going transfer molding, attempts were made cast insulating material around this insert Fig. 6—The copper foil inserts this molding are only 0.00! in. thick. assembly, without success. After its adoption, the job was put into pro- duction, using general purpose phenolic molding material. The variety small parts shown Fig. indicates the possibility producing such delicate things coil forms with molded-in conductors, in- tricate dental instruments known pulp testers, molded insulation tween tiny collector rings and small armature shaft, minute bushings with hole only few thousandths inch diameter running its entire length, spools with thin walls, insula- tion supporting delicate contacts. The syphon bottle head shown Fig. good illustration what may accomplished part which combines difficult coring problem with the use metal inserts. All these applications far de- scribed were produced from wood flour-filled phenolic molding material, unquestionably the most readily mold- able type the thermosetting group plastic materials. For some appli- cations, the wood flour-filled molding materials were not strong enough meet the service requirements. The question then came up, can the extra- strength, shock resistant materials fabricated this molding process? The molded gear, Fig. further evidence the successful results ob- tained through the use shock re- 7—A variety small parts with tiny molded-in inserts, wires, bushings and delicate contacts. — THE IRON AGE, May 20, > n | 2S | = — sistant materials. this case, four sprues, each about in. diameter, were used connect the pressure chamber the mold cavity. + j 9—This gear was molded the transfer process, using fabric base, shock resistant material. 50—THE IRON AGE, May 20, 1943 Syphon bottle head. This represents the use metal inserts with complicated coring the body the piece. 10—Telephone field sets are molded shock re- sistant materials the transfer process. Telephone handsets, Fig. 10, which must withstand rough field service with our armed forces, are also pro- duced from shock resistant materials. The piece shown the illustration was molded angle press equipped with two hydraulic rams, one hold the mold closed, the other exert the necessary force the pressure cham- ber. this arrangement, not necessary maintain the differeutial ratio previously mentioned above, be- tween pressure chamber and cavity area, inasmuch the mold held the closed position means the auxiliary hydraulic ram. Mineral-Filled Group Some the most difficult thermo- setting materials mold are those found the mineral-filled group. The two parts pictured Fig. are molded from long fiber asbestos mate- rial. The piece the left in. two pieces are examples where the use long fiber asbestos material adds the difficulty molding. i overall length. Its design and in- sert assembly make difficult mold- ing job best. The commutator shown the right made cop- per segments which are encased long fiber asbestos molding material. Mica-filled molding materials used for low-loss electrical insulation have always been difficult mold. The radio coil forms shown Fig. are made from this type material. Here two-cavity mold with single round pressure chamber was used. The airplane ignition parts shown Fig. are not only massive section, but also include complexity insert assemblies. These parts are being successfully produced duction the transfer method molding. Melamine molding material used order take advantage its superior arc-resistant qualities. The M-52 Fuse Job Probably the most discussed job the plastics industry today the M-52 fuse. The nose and cup are produced compression molding, but the body, which the most compli- cated the three pieces, being produced the transfer method molding, using medium impact phe- nolic molding material. Most the dimensions must held very close limits. This, course, makes neces- sary the very careful checking these parts for dimensional accuracy. Precise gaging indicates that there apparent growth elongation the parts after the molding pressure has been released. Under certain conditions, the overall length these bodies has actually been observed being 0.025-0.030 in. longer than the mold which they were formed. This condition ‘apparently produced combination compressibility and flexibility the molding material. established fact that both these properties are existent phenolic molding material this type. Compressibility may ob- served applying given pressure mold charge material loaded into full positive mold. After suffi- cient time has elapsed for the mate- rial become completely soft and plastic, but not yet set up, double the applied pressure, and the plunger will move down, signifying that the material being compressed. The flexibility molded pieces the time discharge from the mold the basic principle which millions bottle caps have been produced the so-called stripping process. With these two conditions known exist, seems logical assume that the elongation the parts ques- tion brought about the mate- rial’s cavit this parts lievir withi ble plain M-52 are for seem close and now prov also dime mold mold the Pate Plas the the then essa low pres not sure nozz that duri into rapi ing can rule meti few able mold rial’s being compressed the mold cavity under high pressure. When this external pressure released, the parts then expand elongate, re- lieving the internal pressure built within the piece. This made possi- ble due the flexibility the molded part the time discharge. This theory may also help ex- plain why cracks are sometimes en- countered the molded body the M-52 fuse. While internal stresses are undoubtedly directly responsible for the cracking that takes place, seems highly probable that there close relationship between this action and elongation. Investigational work now being carried may not only prove this theory correct, but also point the way the control dimensions within the limits through molding pressure. Jet Molding more recent development the molding thermosetting materials the so-called jet Patents have been issued Shaw covering this molding process. Plastics Processes, Inc., Cleveland, the licensing agent. this process, the mold also closed empty and then the material plastic state forced into the cavity through suit- able openings. The basic difference between jet molding and transfer molding the method used applying the nec- essary heat polymerize the mate- rial. jet molding comparatively low temperature maintained the pressure cylinder. The heat input sufficient preheat the material, but not great enough cause react quickly set up. Between the pres- sure cylinder and the mold, there nozzle jet. This constructed that extreme heat may momentarily applied the molding material during the time being injected into the mold. Upon the completion this operation, the nozzle jet rapidly cooled means circulat- ing water. The material left the Conserving PERATORS 30,000 power industrial trucks can help save war-precious rubber following five simple tire conservation rules worked out the service engi- neers Elwell-Parker Co. country’s Avoid broken glass and sharp metal chips. Tires can ruined few days having pieces rubber gouged out sharp pieces ma- terial. RIGHT 12—These radio coil forms were made mold materials. BELOW 1G. 13—Melamine arc-resisting molding material was injection molded form these complex airplane ignition parts. nozzle solidifies but does not polymer- ize. Thus can made flow un- der heat and pressure even after be- ing held the nozzle for long period time. Due this feature, the molding operation can carried out continuous basis. Standard injection molding ma- chines can converted handle thermosetting materials equipping Rubber Industrial Stay off the curb. Running tires ever obstructions chews rubber and tears the tires off rims. may also damage the truck. Keep out chock-holes. Avoid depressions and cracks the floor pavement. Jolts help destroy tires. Keep out oil. Oil and grease attack rubber. Tires should cleaned periodically. Start slowly. Rabbit-jump starts them with the jet molding type heating units. Thus another advance- ment has been made the art molding thermosetting materials. Through the development these processes, the field plastics has been greatly broadened. Jobs that heretofore were impractical, not impossible, are now accomplished facts. Truck Tires can tear miles from tires grinding off the rubber. The rubber problem for these trucks great Elwell-Parker engineers have been collaborating with rubber research men develop tires made new compounds. Conservation also necessary because, with the trucks being used around the clock every day the week many plants, tires are wearing out much faster than nor- mal times. THE IRON AGE, May 20, 4 a > )- Mass Production URING the period change the last ten years which has been brought about the gen- eral acceptance arc welding method producing much the machinery and equipment—especially heavy factors operation welding equipment, which the relatively small scale operation several years ago were minor importance, constitute differences major economic importance today’s operations. Some differences between a.c. and d.c. welding machines are sufficiently important warrant care- ful consideration the characteristics each the light mass produc- tion arc welding. marked contrast operation some years ago, the operation arc welding establishments mass production basis are characterized the following features: Use large number arc weld- ing machines The use hundreds thousands tons structural steel rolled the mill Large quantities arc welding electrodes. (From few thousand 52—THE IRON AGE, May 20, 1943 WALTER BROOKING Director Testing Research, LeTourneau, Inc., Peoria, ° ° ° pounds year million pounds year) Large amounts electrical power Often several hundred welding operators, frequently including the training large numbers oper- ators The use jigs and positioning fixtures permit downhand welding, the use greater amperages and larger electrodes for regular produc- tion work The manufacture large va- riety shapes, sizes and quantities parts and structures the same plant (see Figs. and Controlled procedures often based time studies and operating close time schedules The use coated electrodes in- stead bare electrodes There are several reasons for the large preponderance a.c. machines being used some leading welding organizations. Most these differ- ences are comparatively minor when viewed comparison one ma- chine the other, and most them deal with the quality speed operation rather than inherent mea- surable differences between one ma- chine and the other. There has been much careful study and research completed the differ- ences between a.c. welding machines and d.c. welding equipment, and close and unbiased evaluation the data seems lead the conclusion that there are few differences significance between them means making good welds econ- omically practical basis. Both have been tried and tested large enough scale and wide enough variety work prove that either prac- tical for modern are welding practice, from the “quality welding” stand- point. However, considering the mass pro- duction the machinery and equip- ment aspects are welding, there seem merge three differences favor a.c. welding. Two are mea- all-welded scrapers (upper) and angledozers shown here are only fraction week's mass production output one plant. 300 welding machines this plant, 290 are a.c. machines. These 290 machines deposit about 45,000 Ib. electrodes per week. sura cost sum well tical tion: geth duct mad favo ator erat show cost yet may mac cost: gene ten tage tion: whic ‘ > with A.C. Welding surable and easily defined, (1) cost maintenance; (2) power con- sumption. The third variable and well recognized but not very fully discussed terms its effect mass production, namely, the prac- tical elimination blow. Maintenance Costs Compared The maintenance cost 100 machines the transformer type amounts sizable difference costs chargeable overhead expense, compared either d.c. a.c. motor- generator type machines which have comparable capacity over period ten years. The first cost either type machine about the same and can written off depreciation about the same length time; but the addi- tional cost maintenance the motor-generator type machine, to- gether with the time lost from pro- ductive operation while servicing being done and repairs are being made, leaves valuable margin favor of, the transformer machines when 100 units are involved. The comparison motor-gener- ator a.c. machine d.c. motor-gen- erator machine similar capacity shows significant margin initial cost maintenance the machine, yet some cases the purchase motor-generator type a.c. machine may justifiable for other reasons. motor-generator type a.c. machine has the operating advantage a.c. machine practically eliminat- ing blow. also has the advan- tage making better welding condi- tions with variable current supply which has short variations which the momentum the motor and rotor the machine tends level out bet- ter than does transformer type machine. Power Consumption mass production, difference power consumption between d.c. motor-generator welding machines and a.c. transformer units the same capacity seems discernible favor the a.c. transformer. though the difference not great, even small percentage favor the transformer machine ‘on several Savings maintenance costs and power consumption are appreciable compared d.c. equipment, but the author places greatest emphasis the practical elimination arc blow use a.c. welders. More freedom can used the design both product and welding fixtures, green operators can trained faster and synthetic time studies can readily set where the variable arc blow eliminated. million kilowatts power per year amounts noticeable economic fac- tor. There apparently significant difference between a.c. motor-gener- ator and d.c. motor-generator welding equipment far power consump- tion concerned. Arc blow itself does not seem first very important factor, and yet the mass production welded structures, especially where large plates and modern, curved, functional designs are used, where combination setup and positioning fixtures are used, has its definite effect upon either the quality welds deposited the time which takes make the welds. The effects blow enter into almost every major phase mass production are welding, and the practical elimination the use a.c. machines makes welding large operations simpler enough factor considerable importance. The following paragraphs discuss these major phases separately, effected the arc blow. Arc Blow and Freedom Design The use welding the manu- facture complex pieces machin- 2—Here are few examples the great variety parts which can produced economically with a.c. welding equipment. Note that there are thin sections and thick sections; fast-moving parts either heat treated the weld metal as-deposited; large parts and small. q 1 7 n THE IRON AGE, May 20, 3—This all-welded, low alloy, high tensile steel transmission case must withstand the most punishing stresses and service without weld failures. Depositing welds ft. down into the bottom the inside the case must free from arc blow inter- ference assure the very best welds and tie-ins possible. ery requires all the freedom operation the actual welding proc- ess that can practically obtained. ‘The fact that blow more often experienced depositing welds structures where curved units design help form magnetic fields, makes essential that the greatest possible amount blow elimi- nated the selection the manu- facturing equipment. Modern design complicated machinery, involving plates and members, often in- volving deep and complex recesses variety sizes and thicknesses plates, offers difficult enough welding job under the best con- ‘ditions, without including variable factors that can effectively elimi- nated. The large tractor transmission gear case fabricated entirely weld- ing, shown Fig. involves the deposition welds the inside the case curved members and depth more than ft. from the nearest outside opening. order achieve the greatest economies material and maintain the smallest clearances and yet the most effective design possible, this case must IRON AGE, May 20, 1943 welded with the highest practical de- gree perfection. The fact that made low alloy high tensile steel further requires that the welded joints near 100 per cent efficient possible, especially the corners and the points where welds tie with one another, where stresses may concentrated. The fact that the arc blow usually gives less difficulty relatively open welds along straight lines, and more difficulty the corners where welds are started are finished and where they must tie into other welds, pre- sents definite problem the de- signer. The place where the weld must most reliable the place where stresses are most likely concentrated. Often the end weld which finishes deep corner, that ends square inset corner where shapes are being used, such shown Fig. the place where arc blow most likely give difficulty the deposition weld. the hands highly skilled operator, the deposition good sound weld deep corner, such shown Fig. may done with d.c. machine even encounters arc blow trouble approaches the corner. However, will require good judgment his part know how manipulate his are and his electrode how change the location his ground order break the mag- field which causing the inter- ference with his control the the use alternating current with its practical elimination are blow difficulties, the probability poor tie-ins, such shown Fig. greatly reduced. Such defective welds may may not apparent illustrated and therefore times may pass inspection and yet have inherent weakness because poor penetration into the bottom the corner where stresses actually will concentrated most severely. The re- duction the probability such de- fects provides degree freedom design and the possibility reduced factor safety the deposit weld metal such joints, which constitutes welding equipment. The time required redeposit the weld Fig. and the time required cut out lost time under any circumstances. will take longer than the original weld should because the fact that additional heat has been concentrated that area, and may result imperfect weld the end due damage the micro- structure the metal the vicinity the weld. Influence Fixture Design additional measure freedom from are blow and its interference with depositing good sound welds required because the modern prac- tice building welded units many simple substructures which may tacked together set-up jigs and positioned for most favorable welding sub-structures and then combined into finished machines large set-up shown Fig. The parts for structure may set simple parts positioning fixture which has several stops against which the indi- vidual parts may placed quickly and positively without measurement without special positioning study the part the operator. Often such fixture may made such way allow the complete weld- ing the structure while still the set-up jig having the set-up jig swivels hinges which allow the complete positioning each weld for downhand welding. the use such fixtures increase produ ducin electr sition stops ture being usual Fig. tion fields equip neces weldi hi: becau ever the time, freed settir than equip ogniz depos rathe struc jority positi 3 the mec pr str ase ducing both set-up and welding time. Larger and faster burning welding electrodes may used for the depo- sition such welds. Each the stops the set-up and welding fix- ture forms contact with the plates being welded and the framework usually borders the part being welded. These contact and framework parts, together with the structure itself (see Fig. 5), very often the forma- tion very troublesome magnetic fields with the use d.c. welding equipment that are almost eliminated the use alternating current. necessary break his are and stop welding study the manipulation his are order deposit weld because are blow interferes when- ever finds necessary re-adjust the location his ground break the magnetic field, losing time, which expensive. The use alternating greater freedom the design fixtures for setting and positioning parts than does the use d.c. welding equipment. Effect Electrode Size very definite relationship ognized between the increase size electrode and increase speed deposition weld metal. also rather commonly known that structure can welded with the ma- jority its welds the downhand position, larger electrodes may used ° ° ° weld was defective when the first pass was tied into the adjacent welded joints. Arc blow may have caused the lack control the arc which resulted this de- fect. Subsequent passes did not im- prove this weld, which one where stresses are concentrated and tie-ins must good. 5—The sub-structures which make the final body large earth-moving ma- chine are shown this set-up and welding jig. The form the sub-structures and the many contacts the jig plus the framework the jig offer possible sources magnetic fields during welding. A.c. welding equipment gives almost arc blow-free welding even with large electrodes and high amperage. with assurance good welding; that easier for the operator deposit welds the downhand position, and also that the appearance such welds ordinarily considered better than they are deposited the hori- zontal, fillet, vertical overhead po- sition. With increase the size electrode and the attendant in- crease the amperage used for its deposition, there also definite in- crease the probability are blow interference the deposition weld. With the common use electrodes, the increase the blow problem considerable and mass production scale problem real economic importance. The welding shown Fig. be- ing done deep recess plates part the unit where there known the greatest concentra- tion stresses. The welding done with 450 500 amp. and 5/16 in. electrodes, and performed inside positioning fixture without any worry the part the operator, the in- spectors, the designers poor penetration caused possible are blow interference. This splendid a.c. welding application almost entirely eliminates are blow interference. One the largest problems which has faced the welding industry the past five years has been that train- ing large number operators keep with the great expansion the industry. This train- ing process one which, under any represents consider- able investment time and effort. Anything which can done the organization such training pro- gram* the purchase the equip- *See “Training Welders for Indus- April ment used these men production line simplify such training program good invest- ment. will reduce the length time required for the student welder become sufficiently proficient simple welding and from then learn the job. the training new welding operators, the removal the confusing problem are blow represents considerable element economy. Problems Training The unpredictable (at least the untrained operator) nature arc blow adds variable force which seems make the process deposit- ing controlling the are mysteriously fluctuating process. time when the student operator THE IRON AGE, May 20, 1943—55 | ice A by ‘ ple di- — ich 6—Downhand type electrodes, in. long, using 450 500 amp. power, develop real speed and welding economy the job with positioning fixture and a.c. welding equipment. The welds shown being made the in. plates are among the most heavily stressed the unit. this place arc blow elimination doubly important: First for quality welds: second, for speed. giving his best attention and effort learning the problem arc length, speed arc travel, angle electrode the work, manipulation IRON AGE, May 20, 1943 LEFT 7—By holding the electrode the three successive relative positions the joint shown from left right, d.c. arc blow minimized when encountered. A.c. equipment practically eliminates this extra series motions reducing arc blow minimum. Note that the first (left) and third (right) positions are both contrary the common position which the electrode held where arc blow not encountered. BELOW 8—By control procedures and re- moval all unnecessary variables, fol- lowed careful time studies structures such this part earthmoving unit. reliable and well-balanced production schedules can set up. the electrode, formation the crater and the slag and all the other things which necessity must learned, confuse the picture with the unpredictable and variable prob- lem blow lengthen the training program unnecessarily. examination the several text- books commonly used for operator schooling indicates, the space and illustrations devoted it, that are detail and with care. One the suggested methods manipulation avoid the difficulty arc blow illustrated Fig. where, the start the weld, the electrode pointed toward the end the joint and carried angle which directs the welding metal toward the place where the joint begun. the weld progresses, the electrode swung into normal depositing position which less acute angle, that the electrode points more nearly down the joint, and then the end the weld approached, the electrode swung that points forward the end the joint. This method spoken being quite effective many experienced operators, and yet involves for the new welding oper- ator variable procedure which inter- feres with the habits which must form the deposition metals the average joints not having combat are blow. The position the electrode the end the weld contrary the normal position the use a.c. welding equipment, this variable practically removed and, therefore, does not present addi- tional, confusing problem dent welder. Polarity Question Additional subjects which require tain amount time and attention the part student welder are standing the polar- ity electrodes and the setting the larity machine wherever d.c. welding machines are used. Until recently, the use d.c. welding machines fied because the lack satisfactory welding trodes for the major- ity mass tion welding pur poses. This justifica- tion there which ety almos ing mass little straig trodes istics. mass other altern steps the fied Wit ductio struct ized Lov knowr new ing velope Additi the chara Inv: expan that cine Saving one ducing / / | | | / | \ tion has been practically eliminated the past two three years, since there are now available electrodes which can used with alternating current sufficiently wide vari- ety welding operations include almost every mass production weld- ing problem. mass production welding jobs, there little object spending time con- fusing the operator with the subject polarity and the ramification straight and reverse polarity elec- trodes and their various character- istics. For practical purposes, for mass production machines and other welded structures today, alternating current effectively side- steps the old problem straight reverse polarity electrodes and allows the student welder learn the simpli- fied fundamentals welding metal deposition more quickly. With the development mass pro- duction methods producing welded structures, the necessity standard- ized procedures and the need for re- Low-Expansion Alloy Made Free-Machining grade the per cent nickel alloy known Invar has been developed, through addition selenium. The new type machines easily, saving ing time, Carpenter Steel Co., de- veloper the new grade, reports. Addition selenium does not alter the metal’s low thermal expansion characteristics. Invar, which has rate thermal expansion approximately one tenth that carbon steel temperatures Masking CELLULOSE sealing cap similar that used for sealing medi- cine bottles has been instrumental many man-hours labor one General Electric’s plants pro- ducing small instrument-type motors. used mask off cylindrical sur- liable time schedules has become item major importance. elimi- nating from the welding process all substructures and structures all the unpredictable variations that can practically eliminated, much more scientifically sound and reliable sched- ules production may established. The elimination the unpredictable and variable phenomenon are blow from the welding process the use a.c. welding equipment step toward standardizing schedules production. Arc Welding and Mass Production Schedules Fig. shows one many structures which are being produced basis schedules built from time studies. schedule which has been determined first establishing definite control all the variables that can prac- tically controlled, including weld size, fit-ups, type electrodes, size the electrode machine setting and position which the weld will de- and then time studies de- termining how long takes make each unit. removing from the variable blow, with its atten- dant lost motion readjusting ground special manipulation take care certain conditions which arise the production these parts, time has been saved and greater degree reliability production schedules experienced the manufacture these structures. also possible build synthetic time values which may applied machines which are being designed and which are not yet built, where the arc blow loss time might difficult predict because the specific nature the design before the unit has actually been put into production. This allows reliable prediction the time and facilities required for its production, well the cost. The reliability the pre- diction made more dependable the elimination the unknown quan- tity blow which would asso- ciated with d.c. welding equipment, simply the use a.c. equipment. HESE drills were used thick test blocks. The drill the left cut through regular Invar and was badly burned. The drill the right cut through the entire block free-machining Invar without failing. The chips the left each drill were produced the tests. and electronic devices, aircraft con- trols, thermostats, etc. Its difficult machining properties, however, con- siderably handicapped its use. Any- one familiar with the difficult machin- ing properties 18-8 stainless steel before the free-machining type came into use will have idea these difficulties. Actually, straight 18-8 easier machine than regular Invar, although the stainless work-hardens while Invar does not. with Cellulose Compound face areas small assemblies during impregnation with insulating varnish. The sealing material comes the form thin-walled tube cap, either which may slipped over the work. air-hardening, the ma- terial shrinks evenly the point where closes down over the surface masked, preventing the impreg- nating fluids from contacting the masked surface area. The area masked requires little subse- quent cleaning, and result, shortened production cycle possible. THE IRON AGE, May 20, re, int ich the ion nat ode yet stu- jects cer- time the dent olar- and the justi- the ctory elec- oduc- pur- Carbon Replaces Dural RPLANE clock-like regularity since 1940, the use plain carbon steel aircraft construction has been publicized, with occasional developments this field being an- nounced. This work has progressed for the most part due the endeavors the steel producers the country RIGHT "Flying Jeep" was de- veloped the Stinson Division Consolidated-Vultee Aircraft recting artillery fire, ground force movements, and aid ground force battle tactics. takes off quickly with short run, climbs very fast, and can hover speeds lower than miles per hr. 58—THE IRON AGE, May 20, 1943 attempting interest the research and development engineers aircraft builders, but the progress was com- paratively slow until, because the war, other materials scarce. The progress that was made was series single steps rather than steady growth, and, because 3 SEL AGE the serious shortages aluminum that occurred during the early months the United States’ participation the war, carbon steel replaced alumi- num more than any other single vital material. However, research many special specific aircraft parts has resulted apparent trend that LEFT perforated hard carbon steel strip, 0.008 in. thick, electro galvanized and bonderized, are formed continuously into the fuselage stringers. These stringers are the same weight the aluminum one which they replaced. a ~ promi Per ment bon the ment been string Army Britis string and and string Conso most run. grour IG. that ben tour ° curved the the mar and bend | STRINGERS promises great deal Perhaps the most recent develop- ment the direction utilizing car- bon steels aircraft construction the result research and develop- ment work both Republic Steel Corp., and the Consolidated Vultee Aircraft Corp. Plain carbon steel has been used place dural fuselage stringers the construction the L-5 Stinson “Flying Jeep” for the Army, shown Fig. and the AT-19, developed from the Stinson “Reliant” for navigation training British Naval fliers. These fuselage stringers are full-hard carbon steel and are the same general shape and weight the original duralumin stringers. The “Flying Jeep,” will recalled, the light ship the Stinson Division, Wayne, Mich., Consolidated Vultee, that climbs al- most vertically after short take-off run. used for working with ground forces, designed the IG. Stringers that must formed bent fit the con- tour the ship are curved means the eccentrically mounted roll shown the foreground. This manually operated and full position will place heavy bend the stringer. Combined research efforts Republic Steel Corp. and Consolidated-Vultee Aircraft Corp. have paved the way for another use plain carbon steel air- craft construction. Dural fuselage stringers were re- placed steel without any structural change redesign the ship. “eyes upstairs” for directing artillery fire, the movement troops and mechanized equipment. Origin the development the steel stringers dates back the an- nouncement Vultee* that fuselage Fuselage Panels Ex- panded Steel,” Sherman, THE IRON AGE, Sept. 17, 1942, pp. 54. side panels low carbon sheet stee