The Iron Age 1945-05-24: Vol 155 Iss 21

$1.90 oop $1.50 $1.10 $142.50 58.50 VAN DEVENTER President and Editorial Director BAUR Vice-President General Manager LEONARD Assistant General Manager HAYES Advertising Manager JOHNSON, Manager Reader Service end Market Research BAUR, Production Manager CLEARY, Technical Research and Promotion Manager ° Executive Offices Chestnut and Sts. Philadelphia 39, Pa., U.S.A. Editorial and Advertising Offices East 42nd St., New York 17, N.Y., U.S.A ° ° ° Regional Business Managers New New York 100 East 42nd St. 100 East 42nd ROBERT BLAIR GIBBS Cleveland Pittsburgh Guardian Bldg. Park Philadelphia Chicago Chilton Bldg. 1134 Otis PEIRCE LEWIS WARREN Woodward Ave. Box RAYMOND KAY Los Angeles 2420 Cheremoya Ave. c ° ° Owned and Published CHILTON COMPANY OFFICERS AND DIRECTORS MUSSELMAN, President HILDRETH Vice-President GEORGE GRIFFITHS EVERIT FERHUNE BAUR Vice-President Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE HARRY DUFFY BUZBY THOMAS KANE CHARLES HEALE ° WILLIAM VALLAR, Asst. Treas Member, Associated Business indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price North America, South America and Possessions, Foreign, $15 year. Single Copy, cents. ° ° ° Cepyright 1945. by Chiltee Company (ine. This Vol. 156, No. Editorial Help Wanted—And Offered. Technical Articles Iridite Treatment for Plated Parts. Producing Frangible Plastic Bullets Conveyorized Welding Hardenable Steel. Lead Coated Steels Testing Wire Wrapped Steel Pipe New Features News Front Assembly Line West Coast Personals and Dear Editor This Industrial Week News Industry News and Markets Reconversion Wage Rates Established Fabricating Shops Find Suppliers Adequate WPB Modifies Inventory Controls RFC Training Additional Limitation Orders Revoked Seabees Improvise With Junked Materia! Construction Planning Urged CED Wilson Claims Aircraft Threat Survey Covers Government Plant Disposal Machine Tool Market Developments Nonferrous Metals News and Prices Iron and Steel Scrap News and Comparisons Prices Week and Year Finished Iron and Warehouse, Semi-Finished, Steel Steel Pipe, Tubing, Wire Products, Prices Pig Iron and Coke Prices Stainless Steel and Ferroalloy Index Advertisers May 24, 1945 : ° ° ° $1.23 102 108 0c. 8.75c. EVEN THE Here visible evidence why Mahon finishing any kind has Weldments cut machining and finish- done. costs. tells its own story the quality This unretouched photograph welding skill for which Mahon has gear housing section exactly earned such widespread recognition. came from the hands Mahon fabri- engineers will welcome the cators—with strips the marking collaborating your tape still adhering. welded steel plate requirements. Fabricators Machine Bases and Frames and Many Other Welded Plate Products 40—THE IRON AGE, May 24, 1945 . 4 > F 3 + 4 q ESTABLISHED 1855 May 24, 1945 VAN DEVENTER President and Editorial Directer BAUR and General Manager Editorial ° ° ° Associate Editors JACK HIGHT ALBIN JOHN ANTHONY BARMASEL Assistants HANSEN DAVIS Regional News and LLOYD Pittsburgh 428 Park Bidg. POST Chicago 1134 Otis MOFFETT DONALD BROWNE EUGENE HARDY Washington National Press Bidg. LLOYD Cleveland 1016 Guardian Bidg, BRAMS Detroit Woodward Ave. OSGOOD MURDOCK San Francisco Market St. Editorial ROBERT Cincinnati DEAN Buffalo FRAZAR Boston Milwaukee SANDERSON Toronto, Ont. Los Angeles John McCUNE Birmingham ROY EDMONDS St. JAMES DOUGLAS Help Wanted—And Offered ELLING, the sense the act persuading people buy, began out the window early 1940, after the fall France and the inauguration our defense program. has been virtually non- existent since the attack Pearl Harbor December 1941, and the beginning our war program. Since then selling has abdicated the originator the urge buy, favor Uncle Sam’s purchases and the shortages almost everything. this period new kind salesmanship has come into the picture. consists keeping people sold products that are now unobtain- able almost so. Witness the advertising hard-to-get cigarettes impossible-to-get radios and television sets hundred other prod- ucts short supply. This job freezing consumer demand for use after the war has been very ably done has been the task the individual salesman keeping customer good-will alive even without the ability supply prod- ucts. But this evanescent condition that will pass soon the Japs have taken enough pounding. When that time comes, and won’t long now, the need for the old fashioned sort individual selling that fetches home the bacon will come with it. The ability sell competitive market will sorely needed every branch industrial and commercial activities are maintain the necessary postwar employment. Selling leads the pro- cession the movement goods and certainly will riot reach the goal million more jobs than 1939 unless somebody goes out and gets the orders. This serious problem for every employer and for the country whole. Many thousands our younger salesmen have joined the ranks and are shelling instead selling. They will need retraining when they come back. Many more thousands salesmen are out practice because the buyers and not the sellers have been “accentuating the posi- tive” during the past several years. And add the difficulty, there has been absence the normal influx salesmen into industry and business through this war period. number one problem for employers all kinds will the selecting and training postwar sales personnel. Right now not too soon something about it. help solve this highly important problem, the Committee for Economic Development, through the National Society Sales Training Executives, has issued five helpful pamphlets this subject. Number deals with “Attitude and Preparation”; Number with “Planning the Program”; Number with “Getting Action”; Number with “Checking Results and Following Through,” and Number with “Postwar look for Sales Training.” The set five are available through the Com- mittee for Economic Development, 285 Madison Ave., New York 17, The price per set cents. you have not already secured this very helpful information very important subject, suggest that you promptly. ? a | | ‘ | | cts | | Skin rolls, shot blasted grades roughness, produce Inland Sheets that are easy draw. The roll shown above has been ground, then shot blasted one end show contrast between ground and shot blasted INLAND that revolutionized deep drawing Several years before the start World War improve die performance. This surface for Inland engineers and metallurgists developed anew severe draw jobs” held the die compound, permitted type cold rolled sheet that solved baffling deep control slippage, required less hold-down drawing problem. The part was deep and provided freedom from scoring, result- front fender which breakage had been running ing more uniform draw distribution necessary from 50%. The special sheet produced desirable meeting the intricate drawing re- Inland thousands these modern designers and fabricators. fenders formed with only average breakage. This only one the many product improve- This Inland development was special pioneered Inland—improvements that preparing rolls for the temper mills. Instead are making better equipment for war and that will the usual smooth and bright surface, the Inland help produce finer peacetime products. sheets were given new type surface that per- Inland specialist awaits your call tell you mitted radical improvements about these developments their processing. also enabled fabricators many applications. Bars Floor Plate Piling Plates Rails Reinforcing Bars Sheets Strip Structurals Tin Plate Track Accessories INLAND STEEL COMPANY South Dearborn Street, Chicago = News FRONT Cutbacks effected the medium artillery program were not ouite large expected, amounting about per cent. This cut cut affected 105, 75, and mm. artillery shell production, but and mm. mortar schedules were left untouched. The construction project New Martinsville, Va., for $6,000,000 plant for tungsten carbide shell core operations has been cancelled, have large orders for miscellaneous artillery accessories, including gun tubes. Deliveries transport planes for the air lines under relaxed WPB tions are not expected before the first quarter 1946. Shortages engineering manpower and clearances for plants will hold production. Early assistance for light plane manufacturers will very limited under the "spot authorization" plan. Republic expected get away early start production its light amphibian for personal use the Evansville plant where P-47 production ceasing. Jones Laughlin will close its foundry the Lakeside plant the Otis works Cleveland. Too severe competition from more modern operations stated the cause the gradual curtailment operations the year old plant. Following strike the open hearth department Jones Laughlin, Pittsburgh, men the soaking pit group have been replaced new hires. The company states that considers the men have quit. start automobile production will come July earlier. tions will soon lifted the production spare parts, and truck production will amplified. Production 214,678 passenger cars authorized for this year, subject review the steel situation develops. calling for unlimited production immediately the specter unemployment again haunts industry. Steel officials predict that the auto industry will pay per ton more for steel than before the war, probably anticipating OPA price increases. Farrell, Pa. ordnance plant being shut the 400 employes will absorbed into steel operations there. Producing armor plate for tanks, cutbacks and cancellations have made possible the shutdown. Construction electric furnace melting plant produce high quality steels from California magnetite, located adjacent the Shasta Dam project California being studied the Bureau Mines. Low cost power would the key the project. Most probable postwar annual market for finished steel the far western states will about 3,300,000 net tons annually. This represents.a per cent increase over the average for 1936 1940. The chemical reaction chromium salts with zinc cadmium surface will produce corrosion resistant film that intimately welded into the part This Iridite mixture can also applied hot dip galvanized parts and zinc die castings. The treatment does.not increase dimensions since removes about 0.00003 0.00004 in. the plate while the average thickness the film deposited 0.00001 in. Iridite films are extremely ductile and will normally withstand any bending operation that the plated surface beneath will stand. Lead coatings steel when less than 0.00025 in. thick, whether deposited hot dipped, afford very protection steel exposed the atmosphere. Thinner coatings show more pinholes for given time exposure. industrial, and seacoast atmospheres, copper coat acts retard the initial appearance rust spots the lighter coatings. Where lead coatings are plated directly raw steel, cold rolling will reduce the size and number pores the coating. well the surface. ~ i — to 4 un | | > LLL and cadmium, both basically good protective films steel, are still actively capable corroding. forming coat which keeps air and moisture away from the metal surface, Iridite protects the cadmium plate marked degree. Iridite corrosion resistant surfaces can obtained several colors and finishes. ANY the soluble compounds and salts chromium are able impart some degree passivity metal surfaces. Chrome salts have been used variety conditions for this purpose, for exam- ple, pipe and duct systems through which other corrosive liquids are pumped. Zine chromate primers common paint applications. The Iridite process method treating zinc cadmium surface that will combine with chrome salt such way that the newly formed compound will intimately welded into well the surface. The process permits the deposition sufficient quantity thickness protective compound withstand reasonable amount wear, resistance 44—THE AGE, May 24, 1945 spray, liquids, condensed etc. Iridite the trade name for chem- ical mixture developed Rheem Re- search Products, Inc., 2523 Pennsyl- vania Ave., Baltimore 17, totally owned subsidiary the Rheem Mfg. Co. The larger portion normal business the parent company the manufacture steel drums, hot water tanks and water heaters. Research undertaken increase corrosion re- sistance galvanized hot water tanks, especially critical water areas, led the development Iridite. Primarily Iridite applied cad- mium zine plated surfaces, but the finish now being applied well hot dip galvanized parts and die castings. The coating ALBIN semi-hard amorphous character and produced dipping for short length time the Iridite solution. get Iridite finish with colors other than the standard olive drab bronze, necessary dip the coated part dye solution. coatings irrespective color possess approximately the same degree resistance corrosion, thickness and opacity. Iridite cannot applied directly steel. necessary for chem- ical reaction set between the Iridite solution and the plated metal before true Iridite coating can produced. The compound does not react with steel the same way that does with cadmium and for this reason one way determine whether not part has been prop- erly zinc cadmium plated dip the part Iridite solution. coat will not form areas that have left uncovered the plating metal. The Iridite does not increase the dimension part. The removes about 0.00003-4 in, the plate while the average thickness the film 0.00001 in. The film Aircraft propeller com- ponents made Nash-Kelvinator Pro- peller Division. the upper left part after has re- ceived coating. Compare its luster with the untreated part the right. Below- right propeller hub. finish largely de- termined the sur- face the plate. reduced luster may attained prolonging the dip the hot rinse. ° if ex sis | in t an tor Pro- has re- ompare ith the art Below- yely de- the sur- plate. luster the dip rinse. 2—Variety parts given treatment. The effect external di- mensions negligible. extremely ductile and will normally withstand any bend- ing operation that the plated surface beneath will stand. cleavage plane regarded exist- ing between the base metal and the film. Iridite classified having mild re- sistance abrasion, but has been found general practice that will stand rough handling better than many tyes paints—for instance, Iridited wire has withstood wire drawing operations under standard wire mill practices. great variety products have been produced with Iridite finish, among which may mentioned the following: Aircraft propeller hubs, landing gear struts, gas mask parts, radio panels, zine die castings; and hardware such bolts, washers, and plates, (Figs. and 2). Available Several Colors The most widely (olive drab). Because its camou- flage matching properties and high corrosion resistance, widely used many ordnance components. the preesnt time Iridite comes these colors: Olive drab, bronze, black, green, blue and red. The olive drab and bronze are natural colors, gen- erated result the reaction the Iridite solution with the metallic surface. All other colors are obtained dyeing operation following the Iriditing operation. The dyes are sold separate packages mixed with water and acetic acid and main- tained working range 3.5 4.0 subsequent additions dye acetic acid both maintain range. The Iridite the which all dye operations are done obtain the above dyed colors, and the resulting dyed colors are colorfast and not affect the anti-corrosion characteristics the coating. possible for user have several dye tanks his produc- tion line, but have only one Iridite tank. With this combination can provide corresponding num- ber finishes from one basic Iridite treatment. variation plating and op- erating technique, Iridite olive drab well the other Iridite colors can made lusterless bright ap- pearance, depending the finish the base metal, type plating and Iridite procedure followed. takes the characteristic the under- lying plate. bright plate will tend produce bright Iridite, and, course, both these are affected the finish the underlying metal. bright can also subse- quently dulled variation the time the hot rinse. There another field the use Iridite and that undercoat for paint. the Iridite has char- acteristic providing very satisfac- tory bond for paint protected sur- 3—These three carburetor parts made zinc die castings have been exposed 432 hr. salt spray. The part the left was given olive drab coat before immersion, that the center black coat and the one the right was left untreated. IRON 24, 1945—45 ° ° { { and lors All : that for mine prop- dip have netal. the the ° ° ° THE Worker is Detroi ted setup the Jacobs plant inse adjoining and finally put steaming water bath ight. extreme o c Cc hich will transferred rinse ite tank and ing arrangeme ing shell fuses from tank rack 4—Show lift Propeller hubs suspended racks are de- being lowered into tank Nash- Kelvinator Propeller signe IRON AGE, May 24, 1945 46—TH | Vorker is bath Propeller suspended cks are ered into Nash- Propeller face without sacrificing any the anti-corrosion characteristics the Iridite coating. Extensive tests are now being carried out number paint companies and laboratories, for both air dried and baked enamels. The Iridite treatment essential for both zinc and cadmium surfaces where corrosive atmospheres are en- countered. plated zine surface will show the formation corrosion prod- ucts after only few hours exposure salt spray atmosphere whereas Iridited zine plated surface will with- stand several hundred hours salt spray (Fig. 3). much 700 hr. salt spray resistance has been record- Iridited zinc. The solutions are obtainable concentrated form units—a unit consisting one 12% gal. carboy solution, and one 12% gal. carboy diluted 1-1-8 ratio (one part one part and parts water). Methods Treatment The Iridite treatment extremely flexible and readily adaptable all types processing lines (Figs. and 5). For instance, where user Iridite would like include the operation part his fully automatic plating line which the time cycle must fixed (Figs. and 7), this can accomplished the concentrated solutions maintain the which commensurate with the time cycle required. the case users who wish operate Iridite subsequent operation either the still semi-automatic plating, can follow one two methods operat- ing his solution. may run the working solution complete depletion, dump it, and make entirely new one; may maintain his operat- ing solution his selected optimum working range the additions equal parts and has been found that maximum life the Iri- dite solution can obtained main- taining the the Iridite solution between 2.5 and 3.0. proven that under these conditions, the square foot production the solu- tion increased per cent FIG. 6—An automatic setup Nash-Kelvinator. above that working the solution depletion. The ability regenerate the Iridite solution indefinitely de- pends the size the installation, naturally 500-gal. tank can replenished over greater period time than can solution operating out 50-gal. crock. Due the acidic nature the Iridite and the dye solution used for coloring, necessary have either rubber lined acid resistant brick lined tanks. Stoneware crocks are also satisfactory, but lead lined tanks are not recommended. All solutions give optimum performance room temperatures, but can worked high 100 deg. However, definitely recommended that solutions maintained close room tem- perature practical. plated surfaces, Iriditing opera- tions work best when they are com- ponent part the plating line. (See flow diagram, Fig. 8a). Under such setup, the parts should thoroughly rinsed after removal from the plating solutions, Iridited, cold rinsed, and then hot rinsed. The hot rinsing for the express purpose facilitating drying. This hot rinsing character- istic advantage that greatly reduces labor costs and the need for drying equipment, which otherwise would follow cold rinsing. recom- mended that the rinsing temperature approximately 160 deg. F., which adequate for rapid drying. practical handle the parts imme- diately after drying and some op- erations parts are assembly hr. after Iriditing. Where Iriditing not component part the plating line, and the plated parts have become oxidized, bright dip per cent nitric acid solution, rinse and then Iridite (See Fig. 8b). the parts have been handled are greasy, alkaline cleaner should precede the bright dip. Iriditing galvanized surface, the Iridite part the produc- tion line necessary allow the hot-dip galvanized part cool down approximately 100 deg. F., less, before giving the Iridite treatment. If, however, the galvanized part has become oxidized, necessary also give treatment the bright dip referred above. Iriditing zine die castings (Fig. THE IRON AGE, May 24, 1945—47 4 4 ° q 8c), not necessary condition the die casting with flash plate zinc, but merely clean ac- with the following: Soak hot type cleaner, without current, 200 deg. concen- tration oz. per gal. for several minutes. cold running rinse fol- lows this, after which neutralization (a) Flow diagram continuous plating line with (b) Procedure for removing oxide from previously plated work (c) Procedure for zinc die castings. Cold (a) running rinse Soak Cold (b) type running cleaner rinse Anodex Cold running per gal. rinse 48—THE IRON AGE FIG. 7—Close-up bath the automatic line shown Fig. muriatic sulphuric acid solu- per cent sirength for few seconds. Then cold running rinse, followed Iriditing. Operating Conditions pointed out before, the action the Iridite plated surface Cold running rinse IRIDITE (Alternate) Cold running rinse IRIDITE Cold running rinse Cold running rinse IRIDITE chemical nature dependent upon the three factors time, temperature and pH. these important aspects the Iridite treatment that will now The time and the Iridite bath should closely controlled for desirable results and especially for color. the color may vary over considerable range, from pale blue green deep olive green, the salt spray resistance tests indicate little change corrosive resistance the surface the parts. freshly made Iridite, average thickness plate takes from sec. for complete coating. the solution depletes the process- ing time increases sec. cold solution requires longer immer- sion than warm one. The length time often good index the tem- perature the weakness the bath. some cases longer immersion time may required the result specific plant operation. this case dilution the Iridite solution with equal quantity water will run This may best determined the individual case trial. The time may greatly extended very cold final rinse after plating. fact. this retardation may sufficient prevent the proper forming the Iridite thinly plated work. such case moderate heating the zine rinse tank recommended. definite commercial advan- tage this process that the immer- sion time may varied this simple dilution the solution. Many plants are equipped with full auto- Hot rinse Hot rinse q = 4 HNO; Bright dip als fac HNO3 Hot Bright rinse rinse col (room temp.) upon spects now for for over blue salt little the from ec. mmer- gth tem- bath. sult case with run min. the time very fact, ent the such advan- mmer- this Many auto- matic systems and some protective coating applied over the zinc plating must done process that can fitted the already established cycle the machine. Since simple process figure the neces- sary dilution give trouble-free op- eration any time cycle. Air mechanical agitation can FIG. 9—Part the setup the Chrysler plant also applied the Iridite tank facilitate the action the solution all surfaces the plated objects and especially deep recessed areas the parts. Two Rinses Preferred Two rinses after the Iridite are pre- ferable. Normally, the first rinse running water rinse, the second hot water rinse. The latter kept 150 180 deg. The temperature the hot water rinse has some effect the final appearance the coat- ‘ng. general, the hotter the rinse the less luster the work (Fig, 1). The color tends occasionally lighter after hot rinse. die cast- ings, the reverse may occasionally true. Inadequate rinsing contaminated rinse tanks, due too infrequent tank cleaning, should guarded against. Alkali notoriously difficult remove cold rinsing. When such i alkali carried over the Iridite dip, not only the solution unneces- sarily depleted but blotched and un- even films result, quiring reprocessing. Ragged gray splotches are indication this trouble. Since inadequate cleaning before plating can give similar results good check, where alkali carry-over suspected, hot final rinse be- fore Since the sole purpose the hot practical matter, the hot rinse should kept whatever temperature a 2 4 found give the proper drying the time allowable. This will vary with the work. Drying time largely determined the method handling. Thousands small parts are best rinsed hot water, centrifuged and allowed dry their shipping con- tainers. Centrifuge baskets filled order avoid abrasion from tumbling. Other parts may- ae q 4 Detroit for plating and rockets single line. dried racking them still air, placing dry oven, usually tunnel with warm circulating air. ingenious conveyor setup for taking care the different dipping periods the zine bath and the Iridite solution may found the rocket division the Chrysler Corp., Detroit. Two stages dipping are shown Figs. and 10. The rockets travel the continu- ous conveyor pairs, and the con- veyor raises and lowers automatically, dipping the rockets the various baths they hang from fixtures. THE AGE, May 24, 1945—49 7 Hot rinse $$ fixture from which all the rockets are suspended lowered chains for the immersion period. The motor attached the left side the tank for agitation purposes. This conveyor operates rectangu- lar merry-go-round approximately ft. long and ft. wide. The converyor itself ft. long and operates time cycle 25.65 min., loading unloading, which produces 130 rockets per hour. There are nine dips and drying electro clean tank, then cold rinse, then acid dip, then cold rinse, then plating, then cold rinse, then the Iridite, then two cold rinses and finally into the drying tank. Immersion time the same all these tanks except the zinc plating bath, where the pieces re- plished tripping device which un- loads the rockets automatically from the conveyor belt they dip into the zinc, whereupon they are carried supplemental belt the end the zinc bath slow speed, after which they are picked again the main conveyor belt and moved tank. First the rockets into along. main for min. This accom- ° ° ° ESIGINED facilitate the unloading soft coal where the coal frozen and congealed and will not pass through the unloading trapdoor the gondola hopper car, two drum elec- friction clutch worm-geared hoist operating coal slicer has been developed Silent Hoist Winch Crane Co., Brooklyn 20, The hoist raises and lowers the slicer bar which chops the coal that will flow freely. The hoist mounted any overhead bridge crane that may service and operated from the crane cab. Capacity the hoist 1000 105 ft. per min. With fingertip con- trol, one operator can slice coal all day where formerly several men were needed operate crowbars, sledges and shovels and some cases, too, elaborate thaw- ing ovens torches. ° ° 50—THE IRON AGE, May 24, 1945 rec sta “or sig the dir q . sid kn tio shed un- from into end after ain moved Producing 0.30 caliber molded plastic bullet, developed the com- bined efforts the Bakelite Corp. and Duke University, com- posed essentially lead powder with plastic resin binder. The molded bullet sufficiently strong with- stand the shock firing, but disin- tegrates into fine, harmless powder upon hitting the target plane, spe- cially prepared Bell Aircraft P-63 Kingcobra fighter. The target plane equipped with several pickup devices which automatically record the gunner’s hits stantaneously signal him when “on target.” The plastic bullet and sighting devices are designed that the lessons and techniques learned the gunner during this training are directly applicable combat gunnery using the standard 0.50 caliker com- bat ammunition. Not only this pro- gram inestimable value the bomber gunnery men, but con- siderable help the fighter pilots overcoming the feeling being shot the target planes. well known that there such thing “easy job” until the know-how obtained. The realiza- tion the production requirement for the molded bullet has been ex- ception this, and the story the important part played the tools and equipment the accomplishment these requirements quite inter- esting. The splendid cooperation given the program the plastics molders and tool makers evidenced the fact that five months from the time that the commercial molders were first called together discuss the mass production the plastic bullet, over multi-cavity molds had been constructed. This represented total capacity approximately 3300 cavities, and this time production the molded slug had attained peak over million per month for the industry. This accomplish- ment like many others the field has been possible because the technical skill the metals in- Frangible Plastic Bullets Problems the manufacture the transfer molding dies for the lead powder-Bakelite breakable bullets used training gunners are described the author who was responsible for the development the tools and equipment when was research engineer the Bakelite Corp. Success this heretofore secret gunnery training device and the concurrent training program largely due the efforts Maj. Cameron Fairchild the Army Air Forces Training Command. dustry and those en- gaged the fabri- cation tools and equipment. Fortunately, when the go-ahead signal was given for mass production, the molding ma- terial, molding technique and funda- mental principles mold design had already been established the Bake- lite Corp. small seven-cavity pro- duction mold the transfer type had been designed the writer during his active association with the proj- ect, and one mold this design was constructed and installed the Bake- lite Research and development labo- ratories Bloomfield, J., for trial and evaluation several months prior the initiation mass production the industry. This mold design was the result very careful and exhaustive study all possible de- signs and methods molding the plastic bullet meet the required specifications. The fundamental prin- ciples involved this original design have been used almost exclusively the construction all the production molds now being operated through- out the industry this program. Mold Design Fig. illustrates schematically the general type semi-automatic mold used the production the frangible bullet. most installations the mold the form subpress assembly having top platen and “force,” intermediate platen with transfer pot and sprue plate, and bottom platen with cavity retainer plate and cavity inserts. All three platens are cored for steam heating. These three major WELCH Industria! Hard Chromium Corp., Newark, components the subpress assembly are located relative each other with the aid guide pins, and the entire assembly mount- vertical type, bottom ram press. The novel feature this design the sequence movement the various components closing and opening the press. order at- tain the semi-automatic feature, necessary that closing, the inter- mediate platen remain stationary un- til the cavities close against the sprue plate powdered molding material being used. The mold charged and then the intermediate and bottom platens move together against the stationary force plunger thus extrud- ing the material into the cavities. preforms molding material are used, then the pot may charged with material before the closing the press begun thus eliminating the necessity stalling the press load the mold. Since not possible provide ejector pins for ejection the molded bullets from the cavities because the necessity for extremely smooth surface finish the ogival section the bullet, imperative that the intermediate platen remain absolutely stationary upon opening the press un- til the cavities strip off the molded slugs which are held the under side the sprue plate the “pinched” sprue. the press continues open, collector inserted under the sus- pended bullets, and, when the strip- per bolts finally contact the inter- THE IRON AGE, May 24, x 4 4 = 4 ql q se get mediate platen, the cull and sprues re- main the stationary force with the sprues breaking the “pinch,” allow- ing the bullets fall clear and the collector. After the mold fully opened, the cull then knocked off the dovetail holding slots the under side the force, and the mold then ready for another eycle. The required relative motion the major mold components accom- plished simply mounting slotted friction plates rigidly the top platen, installing adjustable friction devices the intermediate platen. The friction device merely bronze washer held tightly against the friction plate means heavy coil spring and cap screw aligned the slot and threaded into the inter- mediate platen shown Fig. There are three popular arrange- ments the cavity inserts. These are circular, square and hexagonal with the number cavities varying from 100 for the various multi-cavity production molds now operation. The force, pot and sprue plate are made either circular, square, hexa- gonal combinations depending upon the design and disposition the cavities. The hexagonal arrange- ment the cavities with sprue plate approximately in. thick very rapidly becoming the most popu- lar design since has higher efficiency material utiliza- tion. However, the square arrange- ment can made comparable effi- ciency large molds. One commercial molder successfully producing the molded bullet using Lauterbach press equipment with Sprue Cavity ret. 52—THE IRON AGE, May 24, 1945 Cavity insert Bottom platen’ molded bullet and com- pleted round used training aircraft gunners. Cutaway shows section hobbed die. ° transfer molds. This installation has high efficiency material utiliza- tion. the majority installations, the cavities which the bullet molded were hobbed into the cavity insert, after which the insert was rough- finished, hardened and then ground 2—Schematic diagram cavity frangible bul- let. tion. size the external dimensions, circular cross-section cavity in- sert cut away expose the hobbed cavity can seen Fig. Hobbing Tool Steel Dies Hobbing process whereby cavity the desired shape formed hardened steel hob the proper dimensions into the block cold metal shaped. This done either mechanical hydraulic press. general practice, the cavity block usually soft low carbon steel which may case hardened after hobbing and finishing obtain the necessary wearing qualities and re- sistance localized indentation dur- ing the molding operation. the case the bullet cavity inserts, however, was found necessary use oil- hardening tool steel order at- tain the required dimensional toler- ances the completed cavity, since the steel used must possess high degree dimensional stability dur- _ing heat treatment the effectiveness the hobbing technique produc- ing consistent duplicability dimen- sions from cavity cavity nulli- The use tool steel for the insert considerably increased the hobbing difficulties. technique was finally developed, however, which the cavity was hobbed sev- eral stages with subsequent annealing between steps alleviate the hardening resulting from the severe plastic deformation the metal dur- ing the sinking the hob. The de- velopment this phase the gible bullet tooling was pioneered and perfected John Hohl the New- ark Die Co. and his associates. Cavities Chrome Plated 7 Quite early the program was ascertained that particular molding material had been developed for the molded plastic bullet exhibited severe ten- dency adhere the unprotected polished steel mold surfaces, thus seriously impeding the proper semi- functioning the molds. However, through the extensive co- Industrial Hard Chromium Co. and methods were developed whereby the various parts the molds such the force, pot, sprue plate and cavities could precision hard chromium plated. This not only eliminated the sticking difficulties, since this material like most other plastics, does not seriously adhere hard, chromium, but aided (CONTINUED PAGE 128) wm rn — mee 2s ai : | | | -Slotted friction 0 0 rity in- hobbed reby formed rcing proper cold done ydraulic cavity steel after the and re- ion dur- the case oil- at- ty, since high dur- produc- dimen- nulli- for the increased technique rever, sev- the etal The the eered the ates. ted erimental molded evere ten- nprotected ices, thus semi- molds. ensive ler Co. developed pot, sprue precision not only difficulties, nost other adhere 128) versatility the “Water Buffalo,” officially designated LVT (Landing Vehicle Tracked), negotiating various types terrain due the tracks which keep moving through water, over land and mountains. These tracks are part paddle and part tread and are called grousers. When the amphibious vehicle hits the water, the grousers act like paddle wheel, whereas land they dig and pull the vehicle along. Dozens these grousers are attached two tracks, one each side the vehicle the manner caterpillar tread. The tank itself manufactured the Food Machinery Corp. River- side and San Jose, Cal., and Lake- land, Fla., while the United States Spring and Bumper Co. was as- signed the task making the grousers. Because the tremendous importance and need for this type landing barge the invasion pro- gram the war and the large num- bers grousers required per vehicle and for replacement, rapid production was most essential. The complicated shape, the ma- terial from which the grousers are made, the means welding the shapes together, and other steps the manufacturing operation were part the production problems which confronted engineers Spring. The graphs and tables illustrate how these problems were worked out success- fully with efficient and high rate production. Fig. shows the two in. plates welded together deg. The length the base plate 13% in. and the width the curved section in. There approximately in. fillet welding extending completely around the curved plate, with the exception two small skips allow bolts fit into place. The weld specified 3/16 in. continuous bead using AWS type E6013 mineral coated electrodes. The grouser preheated weld- Conveyorized Welding Hardenable Steel Requirements for mass production grousers treads for the amphibious "Water have been met the installation conveyor line with eight welding stations. Passing the tack welded assemblies first through preheating furnace solved the problem holding the preheat temperature within narrow range, best suited for N-A-X 9130 high tensile steel. ing and heat treated after weld- ing, descaled and coated with pri- mary coat zinc chromate. The base plate, after welding, heat treating and shot blast- ing, must flat 1/32 in. Material used for this plate N-A-X 9130, which heat treatable alloy steel furnished the Great Lakes Steel Corp. containing approximately 0.30 per cent carbon, 0.60-0.70 manganese, 0.60-0.90 silicon, chromium and 0.05-0.15 per cent zirconium, with sulphur and phosphorus the usual range. Some the factors which have been taken into consideration can thus readily First, there the welding the complicated shape involving locked stresses the weld. Secondly there the metal- lurgical problem are welding 0.30 per cent carbon self-hardening alloy steel. heat treating factor and resulting warpage, plus addi- tional warpage from descaling op- eration, also enter production problems. HANDOVA Assistant United States Spring Bumper Co., Los Angeles study mod- ern welding meth- ods proved that the greatest speed and efficiency could achieved through modern continuous methods manufacture. Manpower shortage was also important factor deciding upon this method oper- ation. So, conveyor system weld- ing, heat treating, descaling and painting was worked out that provided high speed production, decreased the necessary man hours, brought minimum the time elapsed between the start the operation and the final finished product, and resulted uniformity the product. Preliminary Tests The method manufacture hav- ing been decided upon, was then necessary make thorough study metallurgical factors order guarantee this uniformity product. First, was vitally important select electrode which would give sound, crack-free weld deposits and would acceptable for welding conveyor line. test was therefore grouser for the fabricated arc welding hot formed section N-A-X 9130 high tensile steel flat plate the same material. THE AGE, May 24, 1945—53 | 54—THE IRON AGE, May 24, 1945 FIG. 3—Setup man assembling grousers opposite side table shown Fig. conducted follows: Two in. plates were together the form and fillet weld was run along each side. After welding, the various assemblies were carefully cut apart intervals approximately in, and inspected for auto-cracks, fusion zone cracks, porosity, depth penetration, slag inclusions the root the weld and the formation crater cracks the finish the pass. Two electrodes which appeared give the desired results were selected. The next factor considered was the proper preheating tempera- ture. After careful study the prob- lem, the “single bead” test was de- cided upon means for selecting this temperature. Strips the ma- terial welded were secured and single bead was laid these strips which were preheated 200, 300, 400 and 500 deg. respectively. Data were recorded for burn-off rate, elec- trode used per inch weld, depth weld penetration, cracks, porosity, maximum hardness area, and the weld ductility. The ma- terials used this test were Fleet- weld 3/16 in. electrode and N-A-X 9130 in. steel plate. The machine setting was 160 amp., volts. Re- sults this test are given the table. The conclusions drawn were that the 500 deg. preheat would most satisfactory gave low hardness the metal being welded with increased ductility. also ap- peared that slight saving elec- trode would obtained. extensive series tests were made compare the use 3/16 and in. electrodes with the conclusion that the in. electrodes would in- crease production per cent, though more weld metal would de- posited. The larger electrode would also save over 6000 man hours fill- ing the original contract, was es- timated. However, the larger elec- trode produces fillet slightly larger than required and hence was not used. Welding Conveyor Material processed the follow- ing manner: From the steel yard the steel moved blanking press. There, both the curved upper part and the base plate are blanked. Holes the base plate are punched simul- taneously with the blanking opera- tion. From the blanking press, the base plates are taken large quanti- ties the start the welding opera- tion. The upper plate moved hot forming press where curved and stamped with designating sym- bol the United States Spring Bumper Co. Then these plates are also moved the welding lines. FIG. 2—Tacking the curved section the grouser the flat base plate. i dis thi the cut ately acks, the pass. pera- prob- de- cting ma- and strips 400 Data elec- depth osity, ma- chine Re- the were low ap- elec- were and lusion in- cent, de- would fill- es- elec- larger used. yard press. part Holes simul- opera- the opera- toa curved sym- ‘ing are the starting point this line, tack welder placed between both welding conveyors. Opposite him sits setup man who places the two parts into tacking jig and then turns the tacking table 180 deg. that now front the tacker, who per- forms the tacking operation and re- moves from the jig (See Figs. and 3). While tacking the part, the setup man assembling new grouser the opposite side the table which again rotated 180 deg. when the first piece has been tacked. The grousers are now ready placed the welding conveyor. man placed the start each continuous welding conveyor place the grouser the line. the same time puts small plugs into two the holes the base plate where the weld metal comes close proximity. This necessary because bolts having specific clearance are later placed through these holes as- semble the grousers the track. Each grouser also painted the base plate with lime wash. This prevent the adhesion the spat- ter from the weld. The parts now move into the preheat furnace zone, Fig. The preheat furnace rectangu- lar box covering the conveyor for distance ft. and approximate- the walls this preheat chamber small gas burners inserted through holes. These are fed with low pressure natural gas. the grousers come out the preheat chamber their temperature exceeds 500 deg. F., but they continue (CONTINUED PAGE 130) 4—Tacked grousers being carried through preheat furnace continuous con- veyor prior welding. Single Weld Bead Test for the Determination Proper Preheat Temperature for Welding Grousers NAX-9130X Steel Preheat temperature, deg. Burn-off rate, in. per Electrode used per inch weld, Maximum hardness heat-affected Weld ductility: Bend in. pin, Electrode used: 3/16 in. Fleetweld Machine settings: 160 amp.; volts. 5—Five the eight welding stations each which small pass welding bead laid out. Welding done along the conveyor for distance ft. THE IRON AGE, May 24, 1945—55 in. ™ | 200 | 300 | 400 §99 : 1% 2 2 1% None None None | 44 35 37 34 q Lead Coated Steels Appraised investigation the virtues and limitations lead coatings steel, and the possibilities substituting them for terne and galvanized materials. Also described efficient method strip- ping lead and lead-alloy coatings. the instigation the Office Production Research and De- velopment the War Produc- tion Board, the Battelle Memorial Institute June, 1943, was designated investigate lead coating steel electrodeposition and other methods and evaluate the quality such coatings. Identified project NRC- 533, the following abbreviated account the experimental work and conclusions this investigation. corrosion tests rela- tively short duration show initial cor- rosion electroplated lead steel two types which appear de- termined atmospheric conditions. The lead coating either darkens ap- pearance acquires film white corrosion product. The next stage atmospheric corrosion involves the ap- pearance pinhole rust spots which either disappear merge into ap- preciable areas rust. The present condition the atmospheric exposure panels leads the following conclu- sions: (1) The lighter electro dipped coatings (less than 0.00025 in.) afford very short-lived protection steel exposed the atmosphere. (2) There significant dif- ference between the behavior elec- tro-lead coatings deposited from the two commercially available (sulfa- mate and fluoborate) baths investi- gated. (3) The number pinholes the coating, which appear rust spots exposure, dependent largely the coating thickness, thinner coat- ings showing more pinholes for given time exposure. (4) industrial, semi-industrial, and seacoast atmospheres, copper undercoat retards the initial appear- rust spots the lighter coat- 56—THE IRON AGE, May 24, 1945 ings, although the rural atmos- phere State College, Pa., the cop- per undercoat appears detri- mental. (5) The effect copper under- coat independent its thickness within the limits investigated (15 (6) Pores the lead coating tend plug with corrosion product and disappear continued exposure the semi-industrial atmosphere Columbus, minimum coating thickness 0.0005 in. greater thickness, initial porosity appears definitely harmless and lower thickness the pinholes spread rather than disappear. Data from panels exposed other types atmosphere are inconclusive this point date. (7) Neither electro lead terne plate having coating thickness 0.00025 in. less affords the equivalent atmospheric protec- tion steel commercial hot-dipped electro-zinc. what thickness lead and zinc the same degree protection can obtained cannot determined the present stage the tests. The atmospheric tests, with the ex- ception those Columbus, are be- ing continued under the auspices ASTM, Committee B-8. The above larly) are subject revision the basis the results more extended exposure New York, Y., State College, Pa., Kure Beach, Wilmington, C., and Tela, Honduras. Conclu- sions and above, will prob- ably not altered subsequent re- sults. number the panels were sub- jected salt spray deg. and controlled fog density. Failure was considered have been reached when rust spots were visible arm’s length. The hot-dipped coatings failed the same length time the 0.000085-in. electro-lead deposits. Under 0.000085 in. electro-lead, copper plate did not appear aid resisting salt sion. Cold reduction did not appre- ciably increase resistance salt cor- rosion. Electro-terne appeared cor- rode more rapidly than electro-lead the same thickness. The resistance salt atmosphere corrosion 0.00025, 0.0005, 0.001, 0.002-in. electro-lead de- posits increased copper under- coat. Early failure heavy lead de- posits may laid imperfections the surface the basis metal. The wax coating (molten Cercon wax, Petrowax, and Petrowax and Dutrex) the lead deposit ultimately failed the salt spray cabinet after 2350 hr. Wax coatings obviously greatly increased resistance salt atmospheres. group panels were subjected controlled humidity test. There was indicated increased rust resistance for lead with copper undercoat humid atmospheres. Deposits more than 0.0005 in. lead, although heavily coated with white corrosion product, showed rusting this type atmosphere. The hot-dip coatings, terne and tin- antimony-lead, showed remarkable re- sistance for the thickness the coat- ings. The alloys did not form the white corrosion products. odd panel, one-half which was dipped molten Cercon wax, definitely indi- the advantage wax. Two scratches visible the waxed area were under the wax, and corrosion started these scratches and traveled just beyond the wax boundary and stopped. Cold rolling tarded the appearance rust. t