The Iron Age 1943-04-08: Vol 151 Iss 14

MIGHTY Hundreds ball bearings permit the gun turret, treads, trans- mission shafts and instruments this heavy hitting brute revolve, They provide the freedom from friction and wear that makes possible today’s mechanized warfare. New Depar- New Departure Division General Motors Corp.. Bristol, Connecticut. ture ball bearings the millions are speeding the day Peace! THE FORGED EEL BEARING Nothing Rolls Like Ball Photo Office War > 1943 THE IRON AGE, published every Thursday the CHILTON CO. (INC.). Philadelphia under act March 1879. yearly North America and South America, Foreign $15. Vol. 151, No. 14. The precision operations worm grinding and gear hobbing illustrated above are typical Cleveland’s forethought producing Worm Gearing for endur- ing service Steel Mills. Even bookful pictures couldn’t tell the whole the priceless element Successful Expe- rience can’t photographed. But profit long years knowing-how when you install Clevelands. began applying Worm Gearing Steel Mill machinery years ago. Today thousands Cleveland Units are taking the punishment all types Mill equipment and the demand for Cleveland grows steel production expands. The Cleveland Worm Gear Company, 3252 East 80th Street, Cleveland, Ohio. Affiliate: The Farval Corporation, Centralized Systems Lubrication. Canada: PEACOCK BROTHERS LIMITED WORM Entered second class matter November 1932, the Post Office repared for Sing! EV — SSS APRIL 1943 VOL. NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager ° Managing Editor, LIPPERT Technical Editor, OLIVER Associate News Editor, JAMES 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 Toronto, Ontario St. Louis BACON Seattle ° ° ° ° ° ° Regional Business Managers Robert Blair, Union Cleveland Fitzgerald, 428 Park Bldg., Pittsburgh Herman, Chilton Bldg., Philadelphia Hottenstein, Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd St., New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd St., 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 North America, South America and Possessions, $8; Foreign, $15 year. Single Copy, cents, Annual Number, ° ° Owned and Published CHILTON COMPANY (Incorporated) Editorial and Advertising Offices 100 East 42nd St. Pub- Price Executive Offices Chestnut and Sts. Philadelphia, Pa. New York, U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, GEORGE 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 at Editorial Open Letter Uncle Sam Technical Articles Manufacturing the Light Carbine Reclaiming Porous Castings Production Short Cuts Training Welders for Industry Nitrogen Bearing and Cr-Mn Coring Kirksite Dies Rust Inhibitor for Shell Cases Automatic Riveting Vultee New Equipment: Small Tools and Gages Features Assembly Line Washington West Coast Fatigue Cracks Dear Editor News and Markets This Industrial Week News Personals and Machine Tool Activity Non-Ferrous Metals Scrap Markets Iron and Steel Scrap Prices Comparison Prices Finished Steel Prices 154 156 158 160 162 163 164 227 ini ] . Copyright, 1943, Chilton Company | 44—THE IRON AGE, April 1943 E’RE having better luck steel, said manufacturer the other 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 most apt get it. Whether it’s fast service, steady, reliable source, cutting fabricating operation that will facili- tate your production, and assist- ance, most apt get what 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 WPB 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, Philadelphia, Jersey City fs | | | | 4 | a Open Letter Uncle Sam Dear Uncle: About two years ago, you found jam. Hitler was over- running Europe and threatening the invasion England. Germany and Japan had been conspiring and conniving world domination for more than years and had millions soldiers and mountains munitions back them up. And there you were practically defenseless, with army speak and not enough guns, tanks, planes ammunition last week full scale combat, even you had had the soldiers use them. You were blessed natural resources. But you throw iron pigs steel ingots invader nor repel him with lumps ore. There was one industry this country that stood between the raw materials and the finished engines war. You called upon that industry for help and you got it. had not done what was next impossible job you would behind the eight ball today; Russia would probably have been beaten this time, and England would not dropping block busters Berlin. refer the machine tool building industry. You can’t make airplane, tank, gun, tin can torpedo without first finding the machine tools with which convert natural resources into munitions. APRIL You have complimented this industry, rightly, its performance. has expanded itself more than eight times productive capacity and because this you now have all the weapons hand sight that you need finish this job. ESTABLISHED 1855 think that you will admit, Uncle, that the machine tool builder is, all our essential industries, probably the most essential war and peace. not think that you want would intentionally put this extremely valuable industry the scrap pile soon the war over. But that just what may happen unless you watch your step. You have piled huge inventories machine tools all kinds your Defense Corp. plants, more than enough satisfy all normal demands machine tool users for several years peacetime produc- tion. If, the need for these tools lessens the war proceeds, when ends, you throw these tools the market you will kill this industry completely. Especially since through renegotiation you are prevent- ing from building surplus capital for maintaining after-the-war employ- ment You are not, sure, naive enough scrap all your tanks and guns and fighting planes after peace declared. You will slush them with oil and keep them ready next time comes. Why then, scrap the industry that makes them possible? if t i f N q | 4 | q | | } | | | | | | ® | | | | | | | | | } | | J i | arr Freighters Battle Ice Again Must Move Record Tonnages Iron Ore Since mid-March crews have been aboard ore carriers the Inland Fleet—preparing for another long season and tonnages iron ore from the Upper Great Lakes Region. Cargo holds have been cleaned, every piece machinery overhauled, boilers repaired, pumps repacked, and the ships painted— everything made ready for the first trips into ice-filled lake waters. Usually the season navigation opens early April and closes late November. Last year the first Inland ships left Indiana Harbor March and the last cargo ore arrived Dec. 13. The Fleet made all-time tonnage YY Yy, Offices: Milwaukee, Detroit record, and the Block, Inland flagship, established new mileage record for such vessels traveling 61,887 miles trips. Iron ore shipments the Great Lakes last year were twelve million tons higher than 1941, and the tentative quota for this year boosted three million tons more than last. But readiness equipment and men any indication, the Inland Fleet can depended upon carry its share this huge tonnage the busy season ahead. Seamen the Inland ships, like the Inland steelmakers, are fully aware their important part producing the “fighting steel” needed for Victory. 4 Ws Yy : al a a | new methods warfare soon revealed the need for more accurate and longer range weapon than the old service pistol. the other hand, this weapon had light, easy manipulate and use small size ammunition that large number rounds could carried the individual. Such weapon the carbine, light semi-automatic devel- oped the request the Ordnance Department the Army. Many private concerns well the Ord- nance Department’s Springfield Ar- mory, entered model guns for test and standardization. all the guns tested and proofed, the Army services involved selected the one now known the Carbine, cal. 0.30, M1. This new arm weighs about less than yard long, and fed from magazine holding rounds. While the same caliber the Garand, the cartridges are only about half long and the bullets are approximately half the weight. The extreme range the neighborhood 2000 yards, but this weapon primarily designed for close quarter defense. Semi-automatic self loading, the gun capable delivering large volume accurate fire upon any designated point area within range. Like the Garand, gas operated, that is, portion the gases liber- ated upon firing are led through small aperture the barrel into gas cylinder underneath. The pres- Lignt Detailed machining operations are published for the first time three the principal components the latest small arm added the weapens supplied the Army. Known the bine, cal. 0.30, M1, being produced leading manufacturer sporting rifles existing equipment, some which dates back 1875. BRIG.-GEN. JAMES KIRK Chief, Small Arms Branch, Ordnance Department ° ° rod slide which extends back ger. might state that requires engage and operate the bolt. minor change design con- the gun fired, the rod and bolt semi-automatic full auto- driven backwards, ejecting the empty matic and vice versa. shell. the same time, spring While the bolt and action the compressed which then drives the and Garand are very similar, bolt forward. During this forward material difference the movement, the bolt strikes against gas cylinders. The gas cylinder the zine spring, and pushes The forward end the oper- chamber. Only few degrees lid this the other hand, the cyl- recess the rod. forged the barrel close the cham- end the cycle, the piece cocked ber and bored for short piston which has play only about in. The short operating rod the carbine separate from the piston but held tight against spring. The force carbine, cal. 0.30, 4 THE IRON AGE, April 1943—47 M | | | | 1 | ~ q ~ ° ° ° j | | | itt : HAMMER SPRING PLUNGER HAMMER TRIGCER SPRING TRIGGER PIN HAMMER PIN PLUNGER HOLE CAMING LUG CAM RECESS GROOVE BARREL LUG HOUSING RIGS BARREL LUG CAMING HOUSING RIBS HOUSING q OPERATING SPRING PLUNGER HOLE LOCKING LUGS Fig. 3—Two views the operating slide the carbine. HAMMER SPRING SEAT TRIGGER SLOT RETAINING OPENING VARD CATCH SLOT PIN HOLE LEFT SIDE MAGAZINE OPENING HAMMER SLOT ? GUARD SAFETY LOCK HOLE RIGHT 48—THE IRON AGE, April 1943 MAGAZINE CATCH FRONT RETAINING HOUSING LEFT cal. 0.30, MI. BELOW side views ceiver, main body the carbine. LOCKING RECESS CARTRIDGE MAGAZINE OPENING REAR SIGHT BASE RETAINING LUGS pee (GUARD LEFT SIDE BARREL HOLE CARTRIDGE REAR SIGHT MACAZINE BASE OPERATING SPRING TUBE RECESS LEFT 4—Right and left side views the triqger housing. OPENING BOLT LUG RECESS SLIDE CATCH HOLE SLOT RIGHT SIDE with which the piston driven back the pressure discharge suffi- cient actuate the operating rod and bolt through the entire cycle turn being spring. the re- Simplicity Emphasized tary weapon vital, for the more parts there are the more machine op- erations necessary for production, and increased chances malfunction the field. The old manually operated Springfield has about parts, the Garand semi-automatic has parts, while the carbine semi-automatic has been achieved with only parts in- cluding screws and pins. number the parts the car- bine are forged large forging shop and among these are the receiver bolt, barrel, operating slide, magazine 2—Trigger housing group 5—Right and the re. tri | | BOW EAR ore Op- ind ted the in- ine catch, extractor, hammer, trigger, trigger housing and firing pin. Drop hammers various sizes are em- ployed and oil gas fired furnaces used for heating the stock. Many parts are forged from bar stock and three impression dies are standard one plant. Forgings are annealed prior machining heat-treating furnaces the batch type, fired with either oil gas. are When one the principal contrac- tors started making the carbine was already production the Garand, the trench gun, various sporting arms for training troops shoot and all kinds military ammunition. New machines were almost impossible procure and machine tool makers had one two years’ backlog orders. Undaunted, this company brought out old machines, some them and years age, built jigs, tools and fix- tures its own tool department and went work mass producing the car- bine. With but few exceptions, these machines are millers, profilers and drill presses, whose only moderniza- tion occurred odd years ago when the millers were fitted with automatic returns place the hand feeds. Most the milling machines, both heavy and light, were the Lincoln type developed years ago for small with from one eight cutters milling many surfaces simultaneously. One interesting part the carbine ABOVE 6—Gang milling operation being performed Brown Sharpe elec- trically controlled miller. LEFT 1G. 7—An old Lincoln adapted for formed milling pro- filing operation. BELOW 8—Special rocking fixture used for circle milling the receiver Van Norman hand miller. THE IRON AGE, TABLE Operations the Carbine, Operating Slide Operation Machine Rough straddle mill ends housing and rough mill left side Rough mill right side housing and bar miller Rough mill top ‘of bar and housing and rear end finger piece............... Miller Rough mill bottom bar and housing, and rear end housing Finish mill bottom bar and housing and rear ends housing............... Miller Finish mill right side bar and Milfer 10. Finish mill top bar and housing and rear end finger piece............... Miller Finish straddle mill ends housing and finish mill left side 13. Mill radius bottom housing and bottom bar lug Miller 14. Mill deg. angle rear end housing below bar lug.................. 15. Mill 0.150 in. radius rear end housing bottom....................... Miller 16. Mill 0.125 in. radius rear end housing left Miller 18. Rough mill excess stock left side bar (front helix groove) 19. Rough mill excess stock left side caming Miller 20. Finish mill left side bar rear end and radius left side caming lug......... Miller 21. Handmill excess stock left side bar, front helix groove.............. Hand miller 23. Mill slot bottom bar rear end finger Miller 24. Rough mill opening top housing lengthwise Ist Miller 25. Finish mill opening top housing Ist step................. Miller 26. Rough mill excess stock out housing Miller 27. Rough mill opening top housing lengthwise 2nd Miller 28. Mill off excess stock left side housing, top rear Miller 29. Finish mill opening top housing lengthwise 2nd step................. Miller 31. Rough out excess stock, from bottom housing, with end mill................. Miller 32. Circle mill radius, right side front finger Hand miller 35. Edge corner, top right side caming Profiler 36. Rough edge bottom housing front Profiler 37. Finish edge bottom housing and piston seat front Profiler 38. Edge undercuts right and left sides housing rear Profiler 42. Rough mill helix groove 43. Finish mill helix groove ........... 44. Spline front left barrel lug.......... 45. Handmill qualify piston seat 46. Handmill barrel shoulder clearance cut 47. Burr 48. Edge 0.350 in. radius right and left sides ribs rear end 49. Edge 0.05 in. radius top guide lug ... special cam cutting machine cam cutting machine own 51. Drill plunger hole—large and small diameter, and endmill and drill spring hole 54. Stamp 55. File and corner £6. Inspect the operating rod slide, illus- trated, which forged from alloy steel. After heat treating and pickling they are cold trimmed crank press and restruck cold drop mer. the machine shop the opera- tions listed Table are then formed. achieve the cam cut the oper- ating slide which engages the bolt lug lock and unlock the bolt, specially tooled Brown Sharpe miller used (Oper. and 43). The work holding fixture mounted 50—THE IRON AGE, April 1943 52. Ream plunger and small diameter 53. Drill slide spring guide rod seat pocket housing rear end......... Drill press vertical arc some deg. The position the cutting tool spindle stationary and the work both ro- tated and traversed horizontally. The trigger housing, illustrated, tedious, although not difficult, part machine. This item first forged shape from carbon steel and then annealed. The complete list machin- ing operations shown Table II. The main forging any small arm the receiver. the part which most the smaller units are attached. The complete list oper- ations this interesting piece given Table III. the case the operating slide and the trigger housing, there are large number Battery being used perform Leland Gifford opening the trigge . ° ° ° ° ° ° « Bench machine being used size the magazine trigger housing. milling and profiling operations, r- well drill press work. Drilling the bolt hole lengthwise the piece, operation 12, somewhat out the ordinary. Special Leland- ° ° ° electrically driven drills with hydraulic feed TABLE Operations Trigger Housing Operation Machine Finish mill top and front Miller 12. 15. 16. 17. 18. 20. 23. 24. 25. 26. 29. 30. 32. 33. 35. 36. 37. 38. 40. 42. 43. 45. 46. 47. 48. 49. 50. 52. 53. 54. 55. 56. 57. 58. 59. 60. 62. 63. 64. 65. 66. 67. 68. 69. 70. 72. 73. 75. 76. 77. 78. 79. 80. 82. Rough mill single and radius front Miller Mill right side bottom rear opening Miller Drill guard pin hole, magazine catch pin hole, hammer pin Rough straddle mill right and left sides front lugs and central lug ..... Miller Finish straddle mill right and left sides front lugs and central lug ..... Miller Burr ream guard pin hole Edge excess stock from magazine opening ...... Spline magazine opening front and rear ends Stiles-Bliss press Broach magazine opening ................ LaPointe broaching machine Edge radius right side front hammer pin hold Profiler Burr ream safety lock hole ..... Drill press Edge left side hammer pin hole Profiler Drill clearance holes front and rear ends hammer and trigger slot..... Drill press Finish edge hammer and trigger slot, Ist depth Profiler Finish edge hammer and trigger slot, 2nd depth Profiler trigger slot from bottom Profiler Drill and end mill clearance for front end trigger Drill press Burr and ream safety lock hole Drill press Edge clearance for front end trigger Profiler Butt mill and drill trigger spring hole and guide Drill press Edge profile bottom guard bow Profiler Profiler Drill, countersink, and butt mill plunger magazine catch retainer Ream plunger magazine catch retainer hole Drill press Burr ream safety lock hole Edqe magazine catch cut ......... Profiler Edge assembling slots rear end, right Profiler Spline slot front magazine opening Horizontal spliner Spline bottom slot for magazine catch spliner Spline front trigger slot Horizontal spliner Hand mill two slots rear magazine opening miller Drill and ream hammer spring quide hole press Ream guard pin hole, magazine catch pin hole, hammer pin hole and trigger spring hole press Burr ream plunger magazine catch retainer hole File and corner ............. Hand broach catch magazine opening Bench — hi 4 ching in the THE IRON AGE, April Gifford drill presses this purpose. machines, illustrated, with each spin- are employed for These are three-spindle individually motor driven. The drill feeds are hydraulic and one motor and pump serve for group three. The drill pressure about lb. The principal feature the set-up automatic pull-out after every 5/16 in. drilling, that is, the drill backed out pull the drillings and then returned automatically. When the hole finished, the drill backed out for good and stops automatically. Drilling this 6-in. deep hole requires about min., during which time the drill will relieve itself some times. Lard oil with soda used for lubri- first, full size drill was tried, but left the surface the hole too rough. Finally smaller drill was adopted and the hole reamed size. After drilling chip clearance hole the bottom, the main hole rough and finish reamed four-spindle Allen drill press. One end the hole then double counterbored, coun- terbored two steps, give clear- ance start tap for internal tread. During these operations, the part held upright leaf-type jigs. Assembly Procedure the manufacture sporting arms during peace times, the parts for each gun are collected and indi- vidual craftsmen accomplish the en- tire assembly from smallest part complete gun. Today, assembly lines have been established, similar those developed the automotive industry, and the gun put together part part passes from hand hand. For instance, one man now puts the front sight and nothing more. first drives key into slot cut the barrel close the muzzle and then forces closed band holding the sight onto the barrel and pins the key. Another operator puts the piston into the gas cylinder and screws the piston lock nut. The piston has head and while free move back and forth the cylinder, the head and lock nut maintain the piston place. The head also acts seal keep the gases from leaking back through the lock nut joint. Still an- other operator screws the barrel and the receiver together. the barrel holds the front sight and the receiver the back sight, both must per- fect alinement. accomplish this, two indicator uprights are employed, one the barrel and one two- handle wrench the receiver. part the last turn, screwing the two parts together, forces the threads into tight fit. 52—THE IRON AGE, April 1943 TABLE Operations the Carbine Receiver Operation Surface grind right and left sides Demagnetize Mill front end Spot mill top Rough mill bottom and angle rear end Finish mill bottom and angle rear end Rough straddle mill guard lug, front end Finish straddle mill guard lug, front end Burr 12. Drill bolt hole 13. Drill chip clearance hole bottom 14. Burr 15. Rough ream bolt hole Rough straddle mill assembling lug, rear end and center 10. Finish straddle mill assembling lug, rear end and center Machine Blanchard grinder Miller Miller Miller Miller Miller Miller Miller Hand file spindle Leland-Gifford drill press Drill press Bench Drill press 16. Ream bolt hole, counterbore hole and counterbore minor and major diameters thread 17. Counterbore barrel seat 18. Edge front face, lower portion 19. Mill radius, right side and rear end 20. Rough mill top 21. Finish mill top 22. Burr 23. Rough mill right side lengthwise (two time) 24. Finish mill right side lengthwise (two time) 25. Rough mill right and left sides sight base 26. Finish mill right and left sides sight base 27. Mill cartridge opening from top 28. Mill magazine from bottom 29. Mill underside bolt way rear end 30..Rough circle handmill radius top hood, front end 31. Finish circle hand mill radius top hood, front end 32. Rough circle hand mill radius top, front end 33. Finish circle hand mill radius top, front end 34. Edge left side cartridge opening 35. Edge bevel right side cartridge opening 36. Edge bolt way, left side 37. Finish edge front end way, left side 38. Rough edge excess stock magazine opening from bottom 39. Burr 40. Spline cartridge opening 41. Spline locking cut, right side 42. Spline corner top right locking lug 43. Spline locking cut, left side 44. Edge operating slide slot 4-spindle Allen drill press Drill press Profiler Miller Miller Miller Bench Miller Miller Miller Miller Miller Hand miller Hand miller Hand miller Hand miller Profiler Profiler Profiler Profiler Profiler Bench Profiler 45. Finish edge front end operating slide slot, and operating slide release slot 46. Edge slot bottom operating slide slot Profiler Profiler Reclaiming Porous Castings RITING and sealing solutions for the reclamation porous castings, Bowman recent issue Foundry Trade Journal points out that sealing solutions Bakelite V.1845 and N.2106 can used.* The former clear The American equivalents are and sold Bakelite Corp., East 42nd St., New used cases fine porosity, whereas the latter solution containing finely divided mineral filler and em- ployed when the porosity grosser nature. These solutions may used for both ferrous ferrous metals, and factory trials have demonstrated conclusively that the results produced are highly satis- factory. There are two main methods, one for small castings, which the seal- ing solution forced into the casting external pressure, and the other, for large hollow castings, which the solution inside the casting jected pressure, thereby forcing the solution through the walls from the interior. The small castings treated the well-known vacuum pressure process, which the cast ings are placed strong from which the air can evacuated. When suitable vacuum has been tained, the sealing solution allowed run from the storage vessel til the castings are covered, which pressure exerted for om omm wm an wo ings havi of oper solu cast veni Cast mac seal ing tive satis- one seal- other, which sub- from cuum- cast- Operation 47. Edge dovetail for rear sight 48. Circle mill bevel top rear barrel hole Mill clearance cut for bolt lug, left locking lug 50. Edge step left side, rear, from bottom Edge out bottom, rear end 52. Burr 53. Edge left side rear, below bolt hole 54, Finish edge rear end bolt way from bottom 55. Edge assembly cut for bolt, right side, rear from bottom 56. Drill assembling pin hole and drill operating slide catch hole Mill operating rod slide catch hole 58. Edge clearance cut rear magazine opening 59. Burr 60. Mill clearance, rear guard lug Edge cartridge cut, right and left sides 62. Edge cartridge guide cut, front 63. Burr 64. Edge profile, top, rear end 65. Edge radius top rear end 66. Burr 67. Straddle mill right and left sides plate recoil lug 68. Straddle mill top and bottom angles plate 69. Edge slot for guard, rear end 70. Burr Mill clearance cut for left bolt lug 72. Mill top lug, rear end 73. Mill bolt lug clearance bridge Spline cartridge leading cut 75. Mill cartridge leading cut 76. Mill deg. angle corner clearance cut, front end, right side (upright cut and horizontal cuts) 77. Mill clearance cut for liner hand guard 78. Ream and countersink guard pin hole 79. Mill clearance cut right side, front lug 80. Spline retracting cam cut Qualify rear bolt hole 82. Stamp draw line 83. Machine and hand tap barrel hole and gage for draw line 84. Qualify shoulders 85. Rough mill clearance for operating spring tube lengthwise 86. Edge clearance cut for operating spring tube —entire length Butt mill and drill hole for operating spring tube plug (from rear) Counterbore seat for operating spring tube plug (from front) 89. Edge corners lower right side, rear end 90. Mill slide operating locking slot Form notch for tube, operating slide spring 92. Burr ream bolt hole 93. Burr and corner 94. Roll inscription Carbine. Cal. .30, MI" top, front end Roll inscription maker top, rear end 97. Stamp serial number top, rear end Machine Hand miller Hand miller Profiler Profiler Profiler Profiler Drill press Hand miller Profiler Bench Hand miller Profiler Bench Profiler Profiler Miller Profiler Bench Hand miller Hand miller miller Special horizontal spliner Hand miller Hand miller Hand miller Drill press miller Reed lathe with slider base Tapping machine Miller Profiler Drill press Drill press Profiler Hand miller Power press Lathe Bench Bench Bench With BakeliteV.18 N.2106 venient time. The solution thus into the body walls the pressure applied the open port, casting, filling the pores. After re- moval from the vacuum-pressure chamber, the castings are submitted baking operation. the case larger hollow cast- example may taken one having several outlets. All but one these apertures are closed, the one being used port for filling the casting with the sealing solution and opening through Which pressure may exerted. The casting may either the trimmed untrimmed condition, since final machining can out after sealing, desired. When the remain- ing exits the casting are effec- plugged and the hollow casting filled with the sealing solution, air that the solution forced from the interior into the pores the metal. Any available pressure from 250 lb. per sq. in. may used. any porosity exists, the solution forced through that sweating occurs the outside surface the casting; although the case gross defects the solution emerges spray. While probable that casting showing such leaks would returned the foundry, may stated that even severe porosity can cured two impregnations the solution N.2106, followed mediate stoving. this impregnation process, which carried out normal atmospheric temperature, some the sealing solu- tion remains within the walls the casting; the next step therein. The solution consists chiefly Bakelite synthetic resin which, the application heat, con- verted from soluble and fusible sub- stance into solid which longer soluble fusible, and which highly resistant nearly all forms at- tack. This transformation known polymerization, and Bakelite this cured condition has known solvent. The first stage the baking process removes and further heating leaves the pores the casting filled with chemically inert solid which cannot removed any pressures applicable the casting service test. order effect this polymeriza- tion, the following adopted, although much latitude permissible: (1) After the pressure exerted for some time considered necessary, the casting drained and lightly wiped with cloth moistened with thinning solution order remove the excess material adher- ing the surfaces the casting. This advisable because, after stoving, the hardened Bakelite adheres strongly and would difficult remove ex- cept machining hand-tool work. (2) The casting now placed suitable oven, well ventilated, ordinary atmospheric temperature. Heat applied that during the first hour the casting brought (185 deg. F.). (3) After the solvents moved, the temperature raised about 110 deg. (230 deg. F.) for hour and finally raised 135 deg. (275 deg. F.) for similar period. When the stoving cycle complete, the casting sometimes refilled with sealing solution and again subjected pressure. This second impregna- tion will test whether all the pores are filled; any sweating can ob- served, the casting ready for second stoving, which, however, seldom required. will noted that the castings have not been subjected the usual hydraulic test; nor this necessary, since the sealing solution itself acts pressure test medium which will detect any porosity and the same time will charge the metal with the filling fluid, thus effecting saving time. fact, water must test liquid, the casting must dried thoroughly before the solution placed therein. course, after the process impregnation and stoving has been completed, the usual hy- tests may carried out. THE IRON AGE, April — ine der iller iller iller iller file ress filler ench Ailler { Ailler niller ofiler ofiler tical pliner pliner rofiler rofiler — | i uated. lowed after / ABOVE LEFT Baskets sheet metal parts, each bearing the inspector’s stamp ap- proval, are slid gravity conveyor and rolled point where they are picked overhead electric crane. LEFT CENTER The overhead crane picks six bas- kets time. single operator controls the crane push-button. LEFT The overhead crane entirely handles the parts through the sequence chromic acid cleansing operations, raising and lowering them into the vats, shown here. The efficiency has effected 100 per cent increase vat capacity. Aft bas low jac the sho pos the con the each ap- veyor are ectric bas- erator ton. andles ations, the cent mechanical handling all sheet metal parts from inspection the prime paint conveyor line has been devel- open Vultee Aircraft, Inc., Dow- ney, Cal. This continuous process has cut the handling parts from five times twice and has increased the capacity the chromic acid tank 100 per cent. ABOVE RIGHT After the cleansing operations, the baskets sheet metal parts are lowered the gravity conveyor ad- jacent the prime coat line. They then roll work stations where, shown above, they are shunted into position for transfer the parts the swiveled trays the powered paint line. RIGHT CENTER The empty baskets, tripping lever, slip the lower section the roller conveyor. they roll gravity the end the line, they are picked special conveyor, shown above. RIGHT Carried overhead, the empty baskets are returned the main sheet metal station, where they are lowered the start the gravity line and released automatic trip, ready for their, next journey with parts. « | Plastics Aircr ITH the enthusiasm young industry some plastics engineers not concede metals any part plane except perhaps, the motor, and not all that. This perhaps extreme viewpoint, but would unwise record against such possibilities some future date. the present time there is, how- ever, great deal interest the suitability plastic bonded materials for primary structural parts air- craft. The existing shortage metals has stimulated swing less critical materials, and much investi- gation substitutes now under way. many cases the aircraft de- signer probably regards this just another headache, and looks forward the day when will longer necessary. Others, however, feel that the inherent property low density structural advantage which basic, and not any other material field. They look confidently the research laboratories cure the ills which have discouraged many, and stopped entirely some am- bitious attempts substitute plastics for metals. The writer has been asked for his opinion the subject. This fair question but very few realize how in- volved is. first thought seems easy select the most suitable mate- rial for aircraft structures the simple promise strength-to-weight ratio. Unfortunately, the problem not that simple. The fact conceded that tensile and compressive strength important, but the ultimate value material based not one property, but the integration all properties. comparison with available metals, plastics have definite advantages; and present, least, just definite deficiencies. mentioned previously, low density gives the structural superiority many appli- cations, and particularly monocoque and semi-monocoque structures where strength against buckling portant. the other hand, there are some cases where densities plastics are disadvan- 56—THE IRON AGE, April 1943 efficiency, and where restrictions impose overall tage—where limitation aerodynamic design necessary tion dimension. Continuing this comparison, the im- portant factor fabrication must considered. conventional designs weight necessarily added joints and fastenings, and aerodynamic effi- ciency decreased external riveted construction. Plastics may some day prove have fabrication advantages, but far the close control required obtain sound cemented joint and the relative brittleness most the structural plastics have proved disadvantageous. Also, not safe assume that metal structural de- sign will remain its present stage development while the plastics in- dustry catches and passes on. Temperature Changes Severe Another serious consideration which faces new structural that uniformity. material For example, con- sider the case sand castings metal compared with forgings. Even the strength sand castings under ideal conditions great that forgings, the fact that cast- ings are comparatively lacking uniformity sitate their use with higher factor penalty against their use. other words, necessary design for the lowest possible strength obtain- able actual production. This where new material, requiring new manufacturing and fabricating tech- nique, serious disadvantage. Allowance has made for the probable difference between the prop- erties ideal test sections made un- der laboratory conditions with skilled help, and the complicated shapes con- tended with under less favorable con- ditions with less skilled help actual production. Usually perience necessary determine what these allowances must be. the case plastics and plastic cements, attention also must di- rected the effects aging. Some times artificial aging will give much the information required, but tests have been made over period tune under present conditions, when time utmost value. Perhaps thé greatest enemy the use aircraft structure the wide tem- perature range which encountered under actual flying conditions. peratures from —100 deg. +165 deg. break down some plastics and adhesives completely and cause grad- ual disintegration others. The lower temperatures make some other- wise superior plastics too brittle, and other useful ones become too soft the higher end the tically all are affected some gree, and again the necessary factor experience rises the disadvan- tage plastics. Provision also must made against dimensional instability stant load which sometimes causes cold flow and which aggravated varying temperatures, especially the higher range. Reviewing these considerations you will see that new material penal- ized with high factor safety til certain that will the job under the worst sible conditions and over able period time. Until paratively recent date there have other disadvantages associated with known for extensive use plastics for major structural parts. The problem applying the high temperatures and pressures ordinarily required large and complicated members nearly insurmountable. Only recently have developments uncovered group plastics combining interest ing physical properties pressure setting properties. Before leaving structural ations, some mention must the many so-called plastic planes which synthetic resins have used plywood bond. The develop ments are most interesting and able, but except for the adhesives used, are not greatly principle from those developed pre stri pro cur mol phy bef i 4 fre ail sol ler int ler pl: CO until eriod isfor- when thé tem- tered Tem- +165 and grad- The and e de- factor dvan- con- you penal- hat com- major and large been new terest- low nsider- given planes nesives Lockheed over years ago, where pressure was applied plywood strips cold-bonded casein glue, produce beautifully molded plywood structural member having compound curvatures and considerable resistance moisture. The newer resins are undoubtely more weather-proof than the first casein glues, but hardly enough warrant all the publicity. The writer recently had tunity examine Lockheed Vega molded plywood fuselage which was years old, and still very good physical condition. would seem that years would good life expectancy for any machine, automobile, motor boat airplane. Certainly, obsolescence sets long before airplane years old. All this may discouraging from the standpoint true plastic airplane, but should not con- cluded that the problems cannot solved eventually. They lems chemical research, and the science chemistry boasts history achievement that should make any intelligent person afraid say, “It cannot done.” fact, these prob- lems will likely solved time, and post war planes may use structural plastics great degree. far the discussion has dealt with primary structural parts, but the largest field plastics aircraft date, and field that very at- tractive, lies accessories and the thousand and one minor parts varying importance that make modern airplane. Their number rate limited only the ability the plasties industry tool and produce. Extensive Secondary Use Undoubtedly the most important secondary use plastics modern aireraft the transparent semi- structural members widely cock-pit enclosures, windows, turrets and gun emplacements. such fields there competition with plastics, lucite and plexiglass, well some the newer transparent resins such those developed Dr. Muskat. All have won their place through. sheer merit. They are indispensible modern aircraft design, basic usefulness has been greatly augmented resourceful develop- ment forming and cementing tech- niques which enable the designer draw transparent structures al- most any size and shape, with the assurance that they can made the industry. which maintain good optical qualities are invaluable contribution the efficiency aircraft, they enable the designer maintain adequate vision with little sacrifice aerodynamic form. new air- plane carries new and larger trans- parent bubble covering some gun emplacement sighting station, and doubt some day the 15-in. guns the coast artillery will com- fortably housed transparent en- closure big the dome Mt. Palomar. From transparent down, almost everything air- plane has been could formed plastic materials. Control wheels, control handles, seats, floors, window frames, trim tabs, pulleys, and pulley brackets, ammunition chutes, electrical apparatus, landing wheels and fuel tanks, are only few the many necessary items which plastics have been used with success. One the organizations that has especially active the use plastics the Glenn Martin Co. who have carried extensive re- search the subject for several years. They have made quite large assemblies, some primary structure, with evident success. Another use which plastics ap- pear better than metals their own merit the construction bullet- proof fuel tanks, compartment linings where such tanks are housed. such locations the fact that bullets may pass through the material without cracking, bulging the structures, very great advantage. One the most important uses aircraft connection with the ex- tensive electrical system which necessary part modern war planes. JOHN NORTHROP President, Northrop Aircraft, Inc. Here radio masts and cases, antenna housings, junction boxes, switches, re- lays, and thousand other gadgets are better parts because they are molded plastic. recent interesting development having wide possibilities stallations. Here ammunition boxes, feed and ejection chutes, ammunition rollers, access doors and gun con- trols all may made well better from fiber plastics than they can metal. such use largely replaces stainless steel, which highly critical war material, doubly valuable. Most interesting have been the re- cent applications plastic parts airplane engines. Complicated cool- ing baffles, push-rod housings, elec- trical harness supports, and similar parts have been prove durable service, and lighter weight than the metals they replace, and their part re- leasing thousands pounds criti- cal metals for service where sub- stitute can found. possible sort and still not cover all the places where sheer merit has warranted the use plastic parts aircraft aircraft accessories. Enough has been said, however, indicate that the field virtually unlimited ex- cept the engineering time and brains available for such develop- ments. plywood structures bonded with synthetic resins are eliminated—which should done, calling such planes plastic surely misnomer—it the writer’s considered opinion that plastic having all the qualities necessary major structural mem- ber, just now emerging from the chemist’s test tube, fact has yet emerged. the other hand, only comparatively small portion the total gross weight air- plane basic structure, power- plant, and everything else, including the pay load, can well product this amazing infant industry that has grown almost over night out bottle the proportion in- dustrial giant. THE IRON AGE, April q ¢ ¢ 3 q j q f é f | ¢ The author pleads for closer cooperation between schools and industry and for more practical training and qualification pro- cedure. details what equipment schools should have and indi- cates the best procedures for either plant outside schools. JOSEPH KLIEB Welding Engineer, Easy Washing Machine Co., Syracuse, fo} ° WANTED: Qualified welders who have knowledge all types welding electrodes; welding techniques and procedures; must un- derstand expansion and contraction, acquainted with existing codes. addition, working knowledge hand and automatic burning, un- derstanding welding symbols, chip- ping and caulking, and layout work. Ability read blueprints would useful. Yes, this the type man every em- ployer would like employ, but where can such men found? present and probably present emergency, welder this sort would very hard locate, but the future the above “wanted” ad- vertisement will the requirement for welders and shall have them, too, because the young welder to- day being taught these things, and furthermore the welders realize these requirements will necessary or- der hold any job after this crisis over. Let’s just back more years, before the organization welding schools throughout this coun- try. The welders that time did not always have the proper training the start, and only through years experience did they become qualified this trade. The tendency that time was that usually both the good and the bad faults welding were 58—THE IRON AGE, April 1943 ° learned and carried the new man who was trained the old time welder. Therefore, there was no- ticeable improvement the work the new man over that the old. that time, men who wanted learn welding asked the welder the job they could try run bead and time they were doing the weld- ing for the welder. Generally the practicing was done joints where the final dressing could done the experienced welder. this man- ner new welders were developed but many them were depositing metal not knowing whether they had the correct polarity the electrode; whether they were obtaining the cor- rect penetration and proper control molten metal eliminate undercut trapped slag the weld. re- sult, there were some failures welding, and the advancement this new field was held back some oc- casions. Then came the realization the faults guard against, and through research and_ the proper worker training again began advance. The men engaged the develop- ment this field came certain con- clusions: There must testing materials welded, testing elec- trodes and finally the qualification the individual welder. Thus, the old time welder and the new man coming had tested before doing the particular job. Many companies set schools train these men for par- ticular classes work. Besides this training there were many welding trade schools started throughout the country. these schools had little knowledge just what teach the student welder and how equip him meet ent conditions encountered the field, Many these schools have been cessful training men while others, due poor management, inadequate instruction, etc. have not been able satisfy employers with the product their schools. Since many companies are now training and qualifying their own welders, might well point out some the best teaching practices and some the faults found trade and vocational schools. Besides, there should more cooperation and under- standing between employers and these schools training and employers should position evaluate the methods and used these schools. Often this question arises among welding men: “How many hours actual training are required duce good arc welder?” The answers will vary from 300 hr. train- ing. all cases these men are prob- ably correct their statements. Gen- erally depends what the welder being trained do. Some men work repetitive production jobs, while others are required work all positions, use various types electrodes and capable coping with many different layouts. man this type would require the 300 hr. training and considerable ence, while the former could learn his operation hr. Still both men are welders. Such factors aptitude for the work, age, sex, physical condition and the effort expended will determine marked extent the time required for training. conscientious learner deposit acceptable fillets and butts any position after the completion his training, but still lacks experi- ence the different conditions exist the beginning, all “ ing ent sho jok the an a Industry ing the actual job, such differ- ent fits joints, root opening varia- tion and different welding machines and electrodes. These are problems which not sure himself when starts new job, but short time acquires this knowledge and gradually gains confidence his ability weld. many cases newly trained welder and often experienced welder will experience “stage fright” when attempting qualify for new job. Employers should learn bear with these new welders giving them fair trial show their ability and skill. Trade and Public. Schools The subject trade school versus public school (vocational) has long been topic for hot debate. The welder does not depend the type school. Good welders have been developed from both sources where schools have had the proper equip- ment, materials, and last, but most important, good instructors and specific course training. has been observed that students paying learn trade show more interest and work harder during their train- ing than some students public in- stitutions. the start this “training era,” there were many poor welding schools, but most these have been eliminated because the more ex- acting requirements, and the fact that the men seeking this training demand that they get the best. This has led f