The Iron Age 1942-06-18: Vol 149 Iss 25

JUNE 18, 1942 JUN 1942 tempo which your plant now works its important This true every step the production —particularly weighing, where speed are basic requirements. weighing equipment meets these requirements greater measure than Fairbanks Scales; weighing equipment has been more carefully designed meet the specialized weighing needs industry « 4 QS £5 S$ d \ ‘ \ = - —— sors — | & One the main reasons why Hoskins Electric Furnaces are well accepted the way they withstand today’s heavy production demands. Thus they avoid the problem work-stoppage. This good service due primarily the tough durability their Chromel elements. Outstanding improvements Chromel the past few years, allow Hoskins furnaces carry the heavier load now demanded men and machines. Hoskins Electric Furnaces the box type are made large range sizes; pot types may also had for melting lead and salts. Our brazing furnaces are fast, and take little floor space. All these furnaces are easy and run. For full details, ask for Catalog Hoskins Manufacturing Company, Detroit, Michigan. HOSKINS PRODUCTS ~ HEAT TREAT ING FURNACES HEATING ELEMENT ALLOYS THERMOCOUPLE AND FIXTURES SPARK PLUG ELECTRODE WIRE SPECIAL ALLOYS NICKEL PROTECTION TUBES THE IRON AGE, published every Thursday the CHILTON CO. (INC.). Entered second class matter November 1932, the Post Office Philadelphia under act March 1879. yearly North America and South America, Foreign $15. Vol. 149, No. 25. Poe 4 JUNE 18, 1942 This Week in... VOL. 149, NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager ° ° ° Managing Editor, LIPPERT News Markets Editor, ROWAN Technical Editor, OLIVER Associate Editors JAMES Art Editor, WINTERS Editorial Assistants BENEDETTO Resident District Editors —THE IRON AGE Editorial Help Yourself More Steel Technical Articles Hydro-Press Forming with Rubber Platens CAMPBELL Forging 90-Mm. Shells Self Contained Presses...... ! | CORRADO SHERMAN Making Machine Tools More Efficiently Cleveland Detroit CHARLES POST Steam and Rocket Aircraft San Francisco Dry-Cleaning Fluids Speed Arms Production Editorial Correspondents Boston Los Angeles HUGH SHARP JOHN McCUNE Milwaukee Birmingham SANDERSON ROY EDMONDS Toronto, Ontario St. Louis BACON Features DIX, Manager Reader Service Washington ° ° Emer Herman, Chilton Bldg., Philadelphia Dear Hottenstein, 1012 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 Warren, Box 81, Hartford, Conn. Johnson, Market Research Mgr. Hayes, Production Manager. Baur, Typography and ° ° News and Markets This Industrial Week News Industry Personals and Obituaries Non-Ferrous Metals ..... Machine Tool Activity Iron and Steel Scrap Prices Warehouse Prices Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Arts Index. Pub- lished every Thursday. Subscription Price North America, South America and Possessions, $8; Foreign, year. Single copy, cents. ° ° ° Owned and Published CHILTON COMPANY (Incorporated) Executive Editorial and Offices Advertising Offices Chestnut and Sts. 100 East 42nd St. Philadelphia, Pa. New York, U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, Vice-President SEORGE GRIFFITHS, Vice-President EVERIT TERHUNE, Vice-President VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY CHARLES HEALE Copyright. 1942. by Chilton Company (ine.) | | | | | ‘ ° ° L ae the case priority ratings based There Something you can get STEEL more quickly! Steel deliveries are problem! Stocks are depleted, mill deliveries delayed, priorities strictly enforced, demands heavier war production intensifies! But there something you can about it—several things, fact! Work closely with Ryerson your requirements, and follow the common sense rules action. Make sure your priority status. (a) you are engaged direct war pro- duction and require immediate stock ship- ments from time time, sure properly extend applicable priority ratings. This should done extending any blanket rating the manner required the blanket under which you are operating properly endorsing purchase orders, certificates. (b) you are not directly engaged war production work, check the proper rating for your repair and maintenance requirements, because effective after May order,amendment No. supplemen- tary General Preference Order M-21-b, establishes closer control and greater limitations the distribution steel. Because the importance following Government regulations the letter, make sure that your orders are formally en- dorsed, using the proper forms when nec- 38—THE IRON AGE, June 18, 1942 essary. This will preclude the possibility further correspondence that might de- lay shipment, prior sale material. When possible, send orders not quiries. This entirely safe because the long-established Ryerson one-price policy. possible the steel, stock, might sold while are answering your inquiry. Whenever practicable, state what alternate sizes, shapes, types steel you can use the desired steel not stock. also helpful indicate the size length which the steel will cut that may fit your requirements avail- able sizes and lengths when regular sizes and lengths are not stock. are most anxious help you with every problem steel procurement application, during these critical days! not hesitate keep closely touch with us. 4 — JUNE 18, 1942 ESTABLISHED 1855 Help Yourself More Steel HIS editorial especially intended for “top executives” the steel using industries. But anyone else welcome read it. addressing the “brass this occasion, because they are the boys who shape the overall policies their companies. They have the say, for example, with regard putting their companies into new line business. going suggest just that them. Gentlemen, urge you into the steel producing business. You can with the expenditure very little capital indeed. You will not need build million dollar blast furnaces and mil- lion dollar continuous mills into the steel business. You can into with what you have already got your own plant. And enough you into this venture cooperative spirit, will far toward solving your problem steel shortages. referring the reclamation scrap your plant plants. course, you now have scrap recovery system operation. matter routine. You have shovel away the chips—no thanks you—or snowed under view the tremendous production drive that you are now putting on. But that’s routine, boys, and here’s where you brass hats come in. You have initiate the exceptions. And need exceptional drive for more scrap you are have more steel. There about that. Scrap reserves today are run- ning behind collections. And you know what that signifies with respect future steel production. For years and years, under the good neighbor policy, have been shipping millions tons scrap Japan. With it, she has built her navy, her tanks and her guns that reduced Corregidor and captured the Philippines. extra offset our kindness Japan. And you can it. Those machines, for example, that you have moved out into the yard make room for new machines for munition making. Those old machines won't back into your production line after the war. They will rusty and obsolete. After-the-war production will require new tool-up. into the scrap pile with them. Those die sets that you have been carefully preserving order accommodate your 1935 and previous customers are the same cate- gory. yourselves and Uncle Sam favor chucking them into the scrap pile. The new America that will build after this war will have room for old models. takes order from “brass hat” initiate anything this kind. That why addressing you big boys particularly. Help yourself and Uncle Sam some more steel. . | | | | } | pen Letter Subject Executive ject the Critical Scrap CHICAGO THE PRESIDENT Much has said and don for more scrap ills running, you men who have control your plants and factories realize the gravity The steel more 1942. hopi make this 55% scrap oducing all the ase our get enough that antial later authorize erything that they not absolutely This second check ecause situation forms. moulds, stee help save their and help win late. Sykes, president Inland Steel Company INLAND STEEL 40—TH IRON AGE, June 18, 1942 are less scrap possible the only own plant and not satisfied and produced more than tell this story your scrap steel will may ° ° HAZLETT WILLIAM SCHROEDER Research Engineers, Lockheed Aircraft Corp., Burbank, Cal. the principal methods forming sheet metal parts the aircraft industry means single acting press, making use comparatively hard rubber blanket confined the upper platen and male form block the lower table. This method made possible the comparatively low quired form aluminum alloys. The economic advantage the process evident when the relative cost punch press dies com- pared with that simple form blocks that require careful mat- ing component parts. ad- ditional advantage arises from this simplicity which permits the use semi-skilled mechanics the work. The importance this forming technique has kept pace with the advent high production rates that are required the present time. fact, production 45,000 parts can made one press single day. The economic fac- tors that originally fostered this process still remain the same to- day, that is, the variety com- ponent parts required per airframe still very large and the total number units produced relatively small, when the aircraft industry compared with the automotive in- dustry. Mass production requires inter- changeability, necessitating close tolerances and uniformity parts. However, has long been known that parts formed with rubber the hydro-press exhibit certain ap- Hydro-Press Forming With Rubber Platens Herein are correlated experimental data the varia- bles involved the forming metal with rubber the hydro-press. There thus established basis for cal- culating and controlling spring-back materials hard temper, the result being greater accuracy parts and increased production aircraft. parently random variations that are particularly evidenced differences the amount which the flanges bent over the form blocks “spring back” when the forming pressure released. Such variation has caused little difficulty when materials soft temper, such annealed aluminum alloy, have been used, be- cause the total amount angular springback has been small and any divergences could readily moved hand straightening. How- ever, with the increasing trend to- ward formation materials the harder tempers, such 24ST alum- inum alloys, springback has become much more important factor and divergences therein have caused more difficulty because they are not readily correctible hand work. empirical study was made determine statistical mean values springback and limits varia- tion was learned that for straight flanges 24ST Alclad material, tolerances deg. could maintained angular spring- back all factors press opera- tion were kept within certain bounds; but that any great de- viation should occur one more these factors, springback results would become widely divergent. was therefore deemed worthwhile make more careful study de- termine the nature the variables springback, and the relative mag- nitudes and importance these variables. Since the work had done one particular press, recog- nized that results, quantitatively, may not exactly applicable other presses and other operating AST series four articles IMPROVED AIRCRAFT FABRICAT- ING TECHNIQUES developed Lockheed Aircraft Corp. The pre- ceding articles dealt with “Drawing Dies for Airframe Contoured Sheet Metal Aircraft Parts," and ing Convex Flanges and THE IRON AGE, June | techniques. However, the very act listing the variables and showing the rather surprising magnitude their effect one press may prove helpful others making similar studies their own equipment. Method Investigation Two basic methods investiga- tion were followed: (1) The spring- back occurring typical straight flanges 24ST Alclad material was measured function such variables press load, rubber hardness, position part the press, and proximity other form blocks, and, (2) since this study in- dicated that variations localized pressure the part might the key all the phenomena observed, the pressure itself was measured the use strain gages embed- ded typical form blocks. The press was Watson-Stillman 4500-ton capacity, having table area 5580 sq. in. view this press operation shown Fig. Under normal conditions, the ap- plied load this press 3500 Shore hardness used. Steel form blocks in. high, simi- lar the one shown Fig. were used for all tests. The sides were 42—THE IRON AGE, June 18, 1942 ABOVE 4500-ton Watson Stillman hydro-press oper- ation. RIGHT form block. undercut shown, forming 98- deg. external angle with the top the block. This enables 24ST clad specimens formed with approximately 90-deg. angle flanges. Since the thickness range from 0.020 0.064 in. now most common use aircraft parts, 0.032 in. and 0.064 in. materials were se- lected representative for these tests. This investigation back angle included studies the effect such factors as: Applied press load, proximity other objects the table, rub- ber hardness, form block height, and certain irregularities inherent hand-made form block radii. Each value shown the following discussion represents average results from six speci- mens tested under similar condi- tions. Good was rea- lized since the maximum observed within each group six specimens was only per cent. Effect Applied Press Load: The table the press was cleared except for the test block which was located the geometric cen- ter, and the applied press load was varied from 1000 3500 tons. The results are shown Fig. Variation press load was found have negligible effect the springback angle the case 0.032 in. material for either in. in. bend radii. However, the springback angle 0.064 in. ma- terial decreased materially with in- creasing press load, approaching for in. radius bend constant value about deg. 3500 tons more. For in. radius bend such constant value = = TIN DEG. A reached within the load range available. Effect Adjacent Objects: Several metal displacement blocks were placed adjacent the test block shown Fig. and the applied press load was varied from 1000 3500 tons. Bend radius was in. all cases. The displace- ment blocks were approximately 5x12x3% in. high and had well rounded corners. Fig. shows the resulting curves springback vs. press load, in- dicated the dashed lines, and compared with the curves, shown solid for the case with the table empty, taken from Fig. Study Fig. reveals that decided ad- vantage was gained from the pres- when 0.064 in. material was formed. The variation springback, in- dicated the slope the curve, was reduced that the springback angle remained virtually constant even with varied press loads. The effect the displacement block the results with 0.32 in. SPRINGBACK ANGLE, DEG. 1000 IN. RADIU With the table empty, the change from Shore hardness rub- ber (solid curves) increased the springback materially and raised the load which approached constant value. With displacement blocks present, the Shore hard- ness rubber destroyed some ex- tent their effect, observed with the softer rubber, eliminating all variation springback with press load. other words, the harder rubber gave less favorable results than the softer. Effect Height Form Block: The effect differences height under the press loads 3500 tons. With the table cleared except for the test block, which was placed the center, both 0.032 in. and 0.064 in. materials were bent over radius form block. Blocks and in. high were used, and parts were formed over each under con- ditions otherwise similar. The ef- fect springback angle shown Fig. may noticed that for both TEST BLOCK AT CENTER OF TABLE -NO OTHER BLOCKS PRESENT 60 SHORE —— RUBBER 24ST ALCLA TABLE AREA = 5560 SQ. IN. 3000 4000 HYDRO PRESS LOAD, TONS material was slight, because the springback angle had already been value comparatively low pressure and further pressure, induced the displacement block, had ad- ded effect. Effect Rubber Hardness: The comparative effect and Shore hardness rubber was also examined. one case the table was empty; the other the ar- rangement shown Fig. was used the center the table. Material thickness was 0.064 in. ABOVE 3—The effect applied press load. RIGHT Arrange- ment form block and displace- ment blocks. materials the springback angle de- creases with increased height form block. The average value springback angle decreased al- most deg. each case when the height form block increased from in. in. Effect Irregular Block Radii: Since radii are often put form blocks rough machining and then polishing hand, was de- sirable determine the effect springback angle the small ir- regularities that result from this method preparation. Two simi- lar form blocks having in. radius were carefully prepared. They differed only that one had “high spot” well within the limits standard shop technique mak- ing such blocks. Specimens 0.032 in. material were formed both blocks under identical press conditions and 3500-ton load. difference deg. spring- back angle was observed between the parts coming from the two blocks. order determine the actual pressures exerted form block under various table-loading condi- tions, pressure gage embodying the electric strain gage principle was constructed. This type gage has already been use the air- craft industry for measuring strains sections under load tests and The gage consists form block, similar those used the preceding work, which are mounted two pressure measuring cartridges; one for indicating the pressure the top and the other the side shown Fig. part (a). The cartridges consist aluminum alloy cylinders placed the block that their faces are flush with the top and side the block respectively. each cylin- der cemented electric strain gage grid, and shown Fig. part (b). flexible set elec- trical leads connects each electric strain gage grid with the neces- ig 9.032 IN. THIGKNESS | 4 THE IRON AGE, June 18, 1942—43 SHORE HARDNESS RUBBER BEND RADIUS = [/4IN. Sie w 16 - --~ -- -+— +— + ~+ THICKNESS $ 4 > - + + 4 2 2000 3000 4000 HYDRO-PRESS LOAD TONS sary bridge-type resistance-measur- the surface the press table was determined with the press operat- ing 3500-ton load applied over table that was clear except for the pressure gage. Rubber Shore hardness from was used the upper platen. The results the tests are shown graphically Fig. similar conditions, but with Shore hardness rubber the upper platen, the pressure dis- tribution the center line the table extending from end end was made. Readings were made one ft. intervals along the center line; the results being shown Fig. 10. The rubber platen with lower Shore hardness produced ing circuit. The whole unit cali- brated before and after each series tests insure accurate results. general, the same basic pro- cedure was used this survey TABLE AREA = 5580 SQ. IN. | MATERIAL THICKNESS = 0.064 IN. the preceding tests order that correlations and pressure variation could made. Both top and side pressures were taken, but only the top pres- sures are discussed this article. SPRINGBACK ANGLE , DEG. The side pressures are similar and only slightly lower all cases. Pressure Distribution The pressure distribution over 1000 2000 TEST BLOCK AT CENTER TABLE-NO OTHER OBJECTS PRESENT. 3500 TONS PRESS LOAD S LOAD TABLE AREA = 5560 SQ.IN. UPPER LEFT Effect table loading. ABOVE 6—Springback vs. hydro-press 0.064 INMATERIAL load effect rub- ber hardness. LEFT 1G. 7—Springback angle height. FORM ‘BLOCK HEIGHT, IN. 44—THE IRON AGE, June 1942 3000 4000 HYDRO-PRESS LOAD, TONS somewhat more even pressure dis- tribution than that observed with the harder rubber. indicated, large pressure variations were observed both tests. Fig. the pressure the center the table was about twice that the ends. However, the dis- tribution from one side the other was reasonably uniform. The variations pressure from end end indicated that the rub- ber was not being restrained ef- fectively the ends the mid- dle the table. order even out the pressure distribution, sev- eral displacement placed each end the table shown Fig. 12. The new pressure distribution the center line shown Fig. 10. The pressure distribution sur- rounding displacement placed adjacent part being formed the press was determined making measurements about block placed the center the otherwise clear table. The results vEF = | Vv | | | | | | ° | | | ade | | | | | } | | | VERTICAL PRESSURE GAGE oer WIRE LEADS TO RECORDER pressure gage assembly show are shown graphically Fig. 11, one quarter the table surface being shown this case. seen Fig. 11, the pressure relatively high for consider- able distance along the axis per- pendicular the block, while the pressure decreases rapidly along axis parallel the length the block. The pressure boosting effect adjacent high objects the table clearly revealed. Pressure vs. Block Height The height the pressure gage above the table, the latter being empty except for the test block, was varied raising the block which was contained. 3500-ton load was applied the press. The in- crease pressure achieved in- creasing the block height shown Table Although tion between springback data and pressure distribution impossible, the results indicate their quali- tative relationships. The differences springback angle revealed the test results described this article are explained the varia- tion pressure the platen brought about the several fac- tors herein described. all cases the springback angle decreased with increased pressure until constant value springback was obtained. Beyond that, increased pressure seems have little effect. was evident that consistent springback angles could not achieved without obtaining, some means, constant localized pressure adjacent the part; preferably operating the press reach the point where springback becomes constant regardless further pressure increase. MILLIVOLTMETER CALIBRATED TO INDICATE PRESSURE ON END OF PRESSURE GAGE (CYLINDER) AMPLIFIER ALTERNATING CURRENT. BRIOGE circuit are shown part Pressure-boosting devices, such increasing the block height and using are beneficial equalizing the pressure over the table. They may also used limited extent produce high pressures over limited region the table form parts from heavy material. However, too many displacement blocks may have detrimental effect because increase pressure one point must compensated balancing de- 2000 1800 1600 1200 PRESSURE, PER 1000 600 600 400 1000 CYCLE OSCILLATOR om part (A) while the details the gage and the block diagram the PLATEN SURFACE PRESSURE GAGE (CYLINDER) ELECTRIC STRAIN GAGE RESISTANCE WIRE GRID. crease pressure somewhere else. Springback angle measurements clearly indicated that much more consistent results with 24ST mate- rial may obtained forming flanges with soft rubber. However, other considerations, such life the rubber and the necessity giving support against buckling during the shrinking convex flanges, requires that some sort compromise reached this point. Irregularities form block radii SHORE HARONESS PRESS LOAD 3500 TONS TABLE AREA=5580 SQ. IN. AVERAGE PRESSURE LB. PER Fig. pressure variation over the platen surface. THE IRON AGE, June 18, 1942—45 / ' 2400 1 ! / 7 200 DISPLACEMENT BLDCKS PRESS OPERATING AT 3500 TONS 54 SHORE HARONESS RUBBER TABLE AREA=5560 SQ.IN. PRESSURE, 4 6 6 DISTANCE ALONG CENTER LINE, FT. SHORE HARONESS 60 TO 65 PRESS LOAD 3500 TONS TABLE AREA 5580 SQ. IN. AVERAGE PRESSURE «132518 PER SO.IN ABOVE IG. The pres- sure distribution along the center line the platen. 2000 LEFT caused the dis- placement block the platen center. & 1000 7 ° ° soo / BELOW 600 / 12—Location displ acement blocks the ends the table. TABLE Increase Pressure Achieved Increasing Block Height Height Form Block, in. Increase Pressure Original New Difference Top Block, Lb. per Sq. In. 260 680 IRON AGE, June 18, 1942 caused objectionable variation springback angles for blocks having the same nominal radii and angles. Such irregularities are virtually impossible eliminate when radii are made Mechanical radius cutters should used standardization springback an- Application Results choice the various methods increasing pressure applied form block often limited existing facilities. However, when choice possible, the following steps are suggested: (1) Increase the applied press load the maximum; (2) place displacement blocks adjacent the form block that requires highest pressure, and, (3) increase the height the form block the maximum permitted the thick- ness the rubber blanket. Since compromise necessary between pressures obtained and durability, has been found that rubber having Shore hardness reading about the most satisfactory. When joggles and convex flanges are not formed completely, will usually found helpful increase the pressure the block well increase the rubber hardness. This may done effectively placing piece hard rubber over the part. Bibliography “Tests Pressurized Cabin Structures,” Howland and Beed, Journal the Aeronauti- cal Sciences, November, 1940. Jackman. Paper presented the San Diego meeting the Society Automotive Engineers, April 19, 1940. “The Development Electrical and Leaderman, N.A.C.A. Tech- nical Note No. 744, 1940. Proceedings the American So- ciety for Testing Materials, Clark and Datwyler. Vol. 38, No. 1938. “Springback Straight Flanges Hazlett, and William Schroeder, Product Engineering, March, 1942. “Elastic Theory Tool Sheet Metal Forming Problems,” Shanley, paper presented the an- nual meeting the Institute the Aeronautical Science, Jan. 30, 1942. 7) | = | | | | : 2200 / / / "7 SURFACE 4, Y 465iN. ALUMINUM KIRKSITE PIGS pp RODUCTION shells the pierce and draw method probably the oldest known method producing high explosive artillery shell forgings. Since World War new types equipment have been adapted for this work that assure greater pre- cision, faster operation and more economical production. firm the Pittsburgh district, for ex- ample, making 90-mm. shells this method two H-P-M self contained Fastraverse presses the rate approximately 3000 shells every hr. Instead using water hydraulic system and battery pumps and weighted accumulator, these presses are in- dividually powered with reversible oil hydraulic pumps and valveless, closed hydraulic circuit. One press pierces the hot slug and the second press “bottoms” the cavity and draws the pierced forging proper length and cross-section. Round billet stock first flame cut 20-in. lengths and these pieces are then flame notched and broken into two slugs equal length. Breaking the billet can accomplished coping ma- chine hydraulic press. The fractured ends are examined for piping seams other flaws before the slugs are heated gas-fired rotary-type furnace. The furnace attendant uses pneu- matically operated tongs load and unload the furnace. These tongs Forging Shells Presses Production the pierce and draw method ver- tical hydraulic presses with self-contained oil systems described herein. article describing simi- lar methods employed for larger shells, but radically different equipment, appeared the Oct. 1941, issue The Iron Age. For complete resumé shell forging practice, the reader referred The Age booklet entitled and Ordnance Manufacture”. are water cooled internally. Each 2170 deg. Uniform temperature throughout required prevent erratic deflection the piercing punch. this, each slug re- mains the furnace for hr. min. The furnace has maxi- mum capacity 280 slugs. After the hot slug removed FROM left right: Slug before heating, pierced slug, final shell forging and forging sawed two show section. THE IRON AGE, June 1942—47 ‘ q 7 4 : 7 ¢ billets that have been flame cut from bar stock are nicked torch, then fractured into two slugs equal length. from the furnace, tumbled be- tween two corrugated cast rollers remove scale. The temperature the slug this point around 2100 deg. The first step the forging proc- ess place the slug the die the piercing press. This press equipped with hydraulic ejector actuated small ram located be- low the surface the press bed. This ram acts cushion and holds the die ejector approximately in. akove the bottom the die. This the hot slug centering ring, held fitted over the top the slug. The centering ring fits into the inside bore the die, often re- ferred the “pot.” The hand manipulated centering ring serves two purposes: (1) centralizes the slug the pot. (2) guides the punch during the piercing operation. die pot rests spherical seat. case the punch tends NEUMATIC tongs, water cooled internally, are used load and unload slugs from the continuously revolving furnace. 48—THE IRON AGE, June 18, 1942 creep any one direction, the pot can moved slightly compen- sate, and thus maintain uniform wall thickness. The press cycle semi-automatic and started the press operator depressing two electric pushbuttons. Pressure re- quired pierce the 90-mm. slug, 125 tons. the upward movement the piercing punch, the pierced slug sticks the punch and brings the centering ring with it, until square flange the top the centering ring strikes two project- ing lugs. This action strips the slug from the punch. The tong man, who originally put the slug the pot, transfers the pierced slug table located between the piercing and drawing presses. The temperature the slug this point around 1750 deg. Besides piercing the slug, the closed end nib lathe center during machining operations. The tong man the drawing press picks the pierced slug and inverts over revolving spindle which removes scale frem the in- side bottom the slug. The slug then placed into the hand manipulated bottoming die the drawing press. The bottom- ing die tapered cup positioned directly top the draw rings. The advancing punch enters the pierced opening the slug, forcing the slug into the bottoming die. The travel the draw punch limited two vertical stop posts which strike square stop blocks the lower die. The length the two vertical stop posts can ad- = 4 = 7 ° ° ° H-P-M hydraulic presses set forge high explosive shells the pierce and draw method. Press right pierces the hot slug, while the one the left does the bottoming and final drawing opera- tion. Only one heat required. justed take care any shorten- ing the punch regrinding. The bottoming operation accom- plishes several purposes: (1) The thickness between the inside cavity and the end the shell forging determined. (2) The metal closed around the tip the punch and chilled that the punch will not push through the closed end during the drawing operation. (3) The pierced slug pered the closed end, that will enter the draw rings easily. After bottoming, the press re- verses soon predetermined pressure (50 tons for the built the two die stops. When reversal starts, the press op- erator pulls lever which slides the two square die stop blocks for- ward, uncovering openings through which the vertical die stops posts travel during the drawing opera- tion. the same time, the opera- tor the right pulls the bottoming die clear the slug. Tongs, chained the press slide, grip the slug keep intact with the punch. The punch advances the second time, forcing the pierced and bottomed slug through the draw rings. Thirty tons pressure re- quired draw the 90-mm. shell forging. When the slug has passed below the last draw ring, spring controlled above it. The press slide strikes electric limit switch which re- verses the press. The upward ac- tion the punch strips the forging from the punch and drops chute which carries out point REMOVING pierced steel slug from the piercing press, the first operation the heated slug. THE IRON AGE, June 18, 1942—49 i operations are performed the drawing press. The pierced slug has just bottomed and now ready forced through the draw rings the lower die. easy access. The temperature the shell forging this point around 1650 deg. There are three draw rings the lower die, located one after an- other with space between them. The rings all have the same outside diameter but have progressively smaller bores. they wear, the lower ring can reground take the position the middle ring and the middle ring reground replace the upper ring. Each completed shell forging checked for depth ensure enough metal make finished shell. 50—THE IRON AGE, June 1942 Every often shell forging placed vertical spindle, where pressure foot pedal accurately centers the inner wall the shell and starts revolving. roller connected dial contacts the outer surface the revolving shell forging and the movement the dial needle indicates any eccentric- ity lack uniformity wall thickness. These two tests warn any changes needed adjust- ment long before the forgings get the government inspectors, thus avoiding any large number re- jects. Final rejections average per cent the total production. ACH shell forging checked for depth see that there enough met- for machining the punches, pots punch guides are swabbed before each operation with oil graphite lubri- punches are cooled between opera- handled, water filled cup lifted over the punch operator. Most the cooling accomplished cir- culating water internally through water passages built punches and around the liners the die pots. Punches require removal for re- and shaping. The change, including adjustment length stop posts match the length the punch, can made about min. change the piercing pot draw rings greatly facili- tated the use the press platens lifting mediums. Change either the lower dies can made approximately min. New dies require greater tonnage for the first few operations until they acquire hard, smooth surface. Use powdered coal dry graphite re- duces the tonnage required new tool. Greater tonnage often needed the metal temperature low. The life the tools quite var- iable. average would around 300 forgings for punches and around 3000 forgings for die pots and draw rings. previously mentioned, these tools can reconditioned and reused. During the piercing operation, regardless whether the punch forced down through the metal whether the metal forced around the punch, there bound scoring the punch. There very little movement metal dur- ing the drawing operation—just the “ironing” the metal around the punch. What important that the drawing punch perfectly smooth that smooth inside cavity obtained the finished forging. The concentricity the forging depends upon the accuracy the piercing operation, and only very slight correction can made dur- ing the drawing operation. There- fore, important that the pierc- ing punch start central and con- tinue central. This can fairly well controlled with short punch but extremely difficult, not im- possible, with long and more less flexible punch. | | New Loader Increases Freight Car Utilization utility device for more effi- cient loading freight cars has been announced Col. Evans, president Evans Products Co., Detroit, freight loading au- thority noted particularly for de- velopment the Auto-Loader for double decking freight cars. The new equipment said insure load stabilization and save movement goods rail transit, “up” the carrying capacity freight cars and away with dunnage ordinarily used for brac- ing, bulk-heading securing freight boxcars. The Evans Utility Loader makes use tooth-notched bars racks attached the sides the freight car, with cross members attached these racks special metal fit- tings. These fittings lock place and can adjusted in- crements lock loads position. these elements possible pro- shipping arrange- ments for almost any type prod- uct. Besides eliminating the use dunnage, the Utility Loader per- mits close and efficient packing goods and adds average five tons the individual car loads. Depending the product shipped, the increase carrying capacity the individual cars ranges from 200 per cent. Metal stamp- ings, farm implements, bombs, shells, machinery, tractors and parts, are among the shipments al- ready made with per cent the damage claims eliminated. interesting aspect the de- vice, which has been used for ac- tual revenue shipments 108 commercial loads over 18-month period, the possibility using wood cars for the duration, necessary. claimed that, since the Utility Loader puts all strains into the vertical beams stan- chions, can stabilize the load permit the use wood sheath- ing for the outside cars. DAPTABILITY the Evans Utility Loader for universal loading shown this view car loaded with variety farm implements. beams mav located anywhere along the length the boxcar half-inch intervals, including the joint two bay members. ex- pansion joint compensates for possible side movement the car. SPECIAL tool tightens cross member against load five hundred mm. shells. The Utility Loader has cut shell loading costs almost per cent and reduced the loading time per cent. THE IRON AGE, June if if : q ° ° Mass Production Anti-Aircraft Gun tremendous importance the gun carriage is, unfor- tunately, overshadowed the more readily evident impor- tance the guns themselves. The introduction aerial warfare and the restoration mobility mod- ern armies has wrought trans- formation gun carriages and brought into being entirely new types. For many years officers and engineers the Ordnance Depart- ment the Army have been designing, creating, building and testing gun carriages all kinds. The results are marvels engi- neering skill and thought. the 52—THE IRON AGE, June 18, 1942 anti-aircraft field, new carriage was called for from which the gun could fired high angles elevation and all around the circle, from one position. One these the 90-mm. anti- aircraft gun carriage which, along with several other types and sizes gun carriages, are now pouring streams under Ordnance supervi- sion. One these manufacturers New England company which did heroic job tooling plant from scratch when tools were had. placed orders with nearly 100 subcontractors. 4 thermore, went into mass pro- duction complicated structure with which had had previous experience. Some idea the complications encountered the manufacture anti-aircraft carriage may gained from the fact that between 4000 and 5000 drawings are re- quired against only 300 400 for the gun itself. However, Ord- nance engineers had incorporated one design feature that eased the production Most the parts these compli- cated structures could cut out plate steel with torch and as- 7 arriages sembled welding. This elimi- nated the long process preparing molds and cores, pouring, cieaning and machining castings. also saved metal and made the carriage lighter. There- fore, this article dwells partly welding and partly machining. might stated right here that this carriage has four princi- pal parts. First the pedestal from which spread out the outrig- gers and trail and which the top carriage mounted. dome sets the center the pedestal. The second main part the top car- riage which carries the gun and recoil mechanism, the traversing and elevating mechanism, etc. This mounted the pedestal means socket, built into the bottom, which rides the dome. The other main sections are the two rubber tired carriers bogies. perforated steel platform, four sections, goes with it, the LEFT line. Gun fore- ground ready for final touches. Gun back- ground being in- spected for firing range. RIGHT ing mill forming trail end pedestal. NEALEY ° order get into production fast, New England heavy cquipment manufacturer used much ingenuity improvising tooling standard machine tools available short delivery and building special purpose machin- ery fast for producing the 90-mm. gun mount. World War the concrete bed coming back, since heavy cast- ings are difficult obtain. equalizing cylinder, the equipoise cylinder and the buffer cylinders. the traveling position, outrig- gers and platforms are folded and the entire gun and carriage picked the wheels. The wheels are removed the firing pos:tion and the mount lowered the ground. The gun and car- riage are then leveled means the dome and socket joint. The first contract for the new anti-aircraft gun carriage was signed about the middle last year and the management imme- diately set work assemble welding equipment, machine tools and operators. quickly reno- vated old abandoned foundry, tearing out the cupola for office and drafting room, and turning the pouring floor into factory. The cranes, disuse for years, repaired. This building was con- THE IRON AGE, June 18, 1942—53 | } ° ° ° G | 4 q q i — verted into machine and as- sembly shop; new building was erected for the weld- ing. Fifty-five boring mills were needed immediately were available, but none were obtainable anywhere any price. The sched- ules all machine tools makers were filled for year more spherical dome into socket with special eccentric driv- ing mechanism motor- driven worm gear and crank with ex- tended angular pin. LEFT HAPER with wooden fix- ture added for shaping outrig- ger journals pedestal. This set-up tem- porary relief for boring mill. ABOVE outriggers are profiled this ma- chine which has been improvised from two Bridgeport unit mill- ing heads mounted horizontally each side the table. Traverse the ta- ble two directions provided the two ball crank levers. ahead with war orders carrying the highest priorities. The plant went into production with make- shift machines until the single-pur- pose machines could designed and built. Four old boring mills, stored one the Ordnance ar- senals since the last war, were ob- tained. Motors and gone, was the factory that built them. New beds were designed and built. D.c. motors were pro- cured, thereby giving these old ma- chines modern drives and variable speeds through rheostat control. Improvisations One example Yankee ingenu- ity was the conversion 24-in. shaper into miller. was brought the requisite height putting 12x12 in. timbers under and angular locating fixture, which hold the work, was built timbers and plate steel. Pre- appearance, this ma- chine, nevertheless, turned out work. radial drill was set boring mill job. Two Bridgeport milling heads were mounted hori- ONCRETE founda- tions purpose, way type ma- chines. Heavy rolled steel plates are bolted the piers. zontally improvised base profile square holes outriggers, thereby taking the place ex- pensive broaching machine. de- vice for lapping the dome into the socket was made from old weld- ments and offset Nu- merous other out-of-date machine tools were borrowed purchased from local mills and retooled pinch hit until better and faster ones could obtained. So, very few months, the had been completed, and with make- shift tooling, gun carriages were rolling out. the meantime plant engineers had designed single-pur- pose machine tools that were fast and efficient, and easy construct. They could built fraction the time takes construct standard machine and with only part the metal. They are de- signed that unskilled workman can operate one with less than week’s training. The machines INGLE-PURPOSE machine for mill- ing outrigger journals pedestal and forming trail end pedestal. The heads are fed angle through hydraulic cylinders, controlled through hand-operated valves. Note the large inserted blade slab and side mills. ~_ are not automatic. They are op- erated manually through hydraulic controls, but perform three more operations simultaneously. Speeds are within the normal lim- its good machining practice. Like the gun most the parts could cut from plate steel and these parts were bolted together. Instead heavy cast iron pedestals, the heavy steel base plates these machines were bolted concrete foundations. Mo- tors and hydraulic pushers were installed and there are four five heads each machine, one oil pump and tank was made serve all. The remaining parts were THE IRON AGE, June 18, = | 5 ° ° « ANOTHER single-purpose, way type machine for drilling and reaming holes pedestals for outriggers. These units heads are also hy- draulically controlled and pedestals are concrete. highly engineered make preci- sion units. Examples include three-way-type machines that three separate groups operations the ped- estal. the first machine, the pedestal weldment centered pilot post and located with side stops. The milling move from four different direc- tions mill the three outrigger slots and the contour the nose. The weldment then transferred second machine, which drills holes the three outrigger sup- ports and pin hole the trail, and welds slot the nose. third machine drills five trail hinge holes and pin hole and mills top side pedestal positioner. Single pass fillet welds are used IRON AGE, June 18, 1942 angle slot the nose for the trail link. Welding Practice ardized machines and equipment feature the weldery. Weldments are sectionalized and progressive straight line production methods are employed where possible with the following mind—(1) Ease handling and welding small weldments subassemblies, (2) reduction welding the final weldment assembly and (3) ease inspection. Each the sub- the parts strict alinement with full allowance for shrinkage distortion. This minimizes tacking and fitting that the welder can easily maintain alinement the jigs and eliminate the tackers and fitters that usually handle such work. The work mounted power driven positioners and can turned any direction that the welder can his work the most using down-hand welding. Electric welding used through- here considered better and faster. Machines 300-amp. capacity are employed rents ranging from 180 315 amp. are used, according size and location weld and material. Diameters welding rods are 3/16 and in. and they are min- eral coated. Single welds the practice all work and including in. thick. The weldery housed building almost 1000 ft. long, length cranes. Two-thirds this build- ing divided three lines welding booths, divided two aisles. The booths are completely inclosed with flame proof canvas suspended from steel pipe frames. There are 125 these welding booths and most them are served with individual jib cranes. indication how the car- riage sectionalized and the sec- tions distributed various weld- ers, consider the pedestal. Subas- semblies weldments are put to- gether individual welders and these are finally welded together make the pedestal. Strength and rigidity are obtained and plate con- served employing box and sections the construction design. Inspection controlling fac- tor all welds are gone over plant inspectors and then again Ordnance inspectors. This starts with the smaller tions, the welds being cleaned shot blasting and given visual inspection first. Next, they are subjected Magnaflux inspec- tion, and all faulty welds marked and repaired. The welds are then X-rayed machine that will penetrate in. steel. The pictures are taken exposures running from 120 ac- cording the thickness the work. All defective welds are chipped out and re-welded. The carriage complete with socket and leveling jack. This weldment carries the gun and recoil traversing and elevating mechanism. in. concrete walls and the doors are covered with sheet lead in. thick. Roentgengrams the work are made the points greatest stress and the number pictures taken determined Ordnance engineers. With the exception the out- riggers and cylinders, all weld- ments are stress relieved fur- nace the car bottom type. The fixtures for the final assemblies are for the subassemblies and indicate mechanism ready for as- sembly top carriage. any out alinement that may have crept in. Here again, allow- ances are made for shrinkage and distortion during the final weld- ing. When finished these final as- semblies are inspected outlined, and then moved crane table with stops for checking for aline- ment and dimensions. Parts likely distort during stress relieving have supporting struts braces welded tempo- rarily during the heating period. While stress relieving produces hard scale, iron oxide powder adheres the work tenaciously that necessary shot blast off. Back the tables the final assemblies are given final inspec- tion and check and are laid out for subsequent machine operations. They then the machine shop. = THE IRON AGE, June 1942—57 — 4 i il ? ° ° ° beds produced fixture the table yooling on Use manufacturers, the Monarch Machine Tool Co., Sidney, Ohio, has had the problem the past two and one-half years in- creasing production its product —metal-working lathes several times over. What the company has story which distinctly individual and unusual. num- ber factors, including the basic- ally important one establishing the outset thoroughly adequate training program for new em- ployees. When, the middle 1941, was decided make substantial increase the floor space and ma- chine tool equipment satisfy de- mands for lathes for the vastly in- creased government program defense preparation, skilled workers the force were picked instructors for the new men hired. Meeting for one hour day during the approximately weeks’ time required for the con- struction new wing the plant, this group men was put through comprehensive course “sprouts” and drilled their new training. Each man was assigned most other machine tool 58—THE IRON AGE, June 1942 to gong definite number teaching units and was helped working out his own job studies. These rough job analyses were worked out the blackboard that all the men each the seven eight groups could benefit the criticism given the director. The initial subdividing the various jobs was done the plan- ning department. The main re- sponsibility the educational di- teach the new instructors how analyze these jobs and organize in- struction sheets them. Each new instructor worked his own notebook, that the conclusion the training course would thoroughly conversant with his as- signment and well prepared train the new men. This plan was carried o