The Iron Age 1936-07-30: Vol 138 Iss 5

JULY 30, 1936 economical vice that must have uninterrupted power—for expansion where existing transmission and trans- former equipment are already working capacity —many manufacturers have found Morse Diesel Engines unfailing and FAIRBANKS, MORSE 106 Years Power, Pumping, 900 Wabash Ave.. Precision and Weighing Chicago. Equipment for DIES MUST ACCURATE WITHIN ONE THOUSANDTH INCH the manufacture Upson bolts, many little things take place behind the scenes insure perfection. Take roll threading dies example. The tool steel used the die blocks special grade developed Upson give the greatest life. Blocks are machined the requisite size. The threading forms, milled into the working surface the blocks with suitable hobs, must accurate within less than thousandth part inch give the required accuracy the threaded bolts that they will later produce. This careful work the machine shop necessary produce the quality for which the Upson name famous. When you examine handful Upson bolts, you see the results painstaking attention the little things—every bolt with clean, sharp, full threads that run easily, withstand power wrenching, speed production, hold tightly and save valuable time and money. Bolts and nuts all stand- ard and special shapes, sizes, It’s just such operations that you and finishes. Standard UPSON NUT DIVISION never think about that make specialties are our specialty, For quality headed and threaded VISIT THE REPUBLIC EX- GENERAL OHIO next order, and note the difference. HIBIT THE GREAT LAKES 2—THE IRON AGE, July 30, 1936 THE IRON AGE, published every Thursday the CHILTON CO., (INC.), Chestnut 56th Sts., Philadelphia, Pa. Entered second class November 1932, the Post Office Philadelphia under Act March 1879. $6.00 year S., Canada $8.50, Foreign $12.00. Vol. 138, No. &, = CHESTNUT AND 56TH STREETS, PHILADELPHIA, PA, Sales Offices WEST 39TH STREET NEW YORK, Owned and Published CHILTON COMPANY (Incorporated) Executive and Publication Offices, Chestnut and 56th Sts., Philadelphia, Pa. FRITZ FRANK, Executive Vice-President FREDERIC STEVENS, Vice-President JOSEPH HILDRETH, WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary FRITZ FRANK President J. H. VAN DEVENTER Editor Managing Editor Editor Emeritus Machinery Editor Art Editor Metallurgical Editor Associate Editors Resident District Editors Washington Chicago Cleveland Detroit Pittsburgh Editorial Correspondents London, England Cincinnati Boston Hamburg, Germany Milwaukee San Francisco SANDERSON ASA JR. ALLISON Toronto, Ontario Birmingham, Ala. Newark, St. Louis Buffalo Conten July 30, 1936 Normalizing Tubes Controlled Atmosphere Furnaces... Solving New York Roofing Problem.................. Sand Testing and Its Application the Foundry........ Putting Automotive Methods into Bath Tubs............ Artistic Bronze Work New Archives Building.......... More Steel for Boulder Copyright 1936 Chilton Company (Inc.) BAUR, General Advertising Manager DIX, Manager Reader Service Member, Audit Bureau Circulations ADVERTISING STAFF Emerson Findley, 621 Union Cleveland B. L. Herman, 675 Delaware Ave., Buffalo, Indexed the Industrial Arts Index. Y.. and Chilton Chestnut Sts., Philadelphia, Pa. tion Price: United States and Pos- Lewis, 7310 Woodward Ave.. Detroit sessions, Mexico, Cuba, $6.00; Can- Ober, 239 39th St., New York ada, $8.50, including duty; Foreign Robinson, 428 Park Bldg., Pittsburgh $12.00 year. Single copy, cents. Sweetser, 239 West 39th St., New York Cable Address, ‘‘Ironage, Warren, Box 81, Hartford, Conn. Member, Associated Business Papers # Go d 5 2h . ’ | | | famous conductor, symphony or- chestra gives rendition great musical mas- terpiece that brings thunderous applause. Yet with the same musicians playing the same notes the but guided the hand conductor who lacks the touch the master, the result entirely different per- formance that, though mechanically perfect detail, falls flat the ears the listeners. It’s the same other fields human effort. The work the genuine craftsman has excellence that cannot measured terms standards fixed for the elements. making Bethlehem alloy steels, the guidance masters the art making fine steels im- parts them super quality, added degree perfection, over and above the aggregate properties specified. IRON AGE, July 30, 1936 ESTABLISHED THE IRON AGE ... JULY 30, 1936 are really Lonservatives usually think the defenders capitalistic system lump the advocates socialism and communism And yet wonder haven't exactly reversed our definitions the radicals are not the real conservatives. terms single life-span, capitalism old and firmly rooted system. For 400 years has spread until today accept the title without question. compared that record, modern communism has been tried grand scale only since 1918 and still trial. That why all think But communism back far beyond the dawn history. Turn the scholars the field primitive human origins read any the authoritative books the and you find evidence that communism existed almost every primitive society. Visit any truly uncivilized portion the globe today and you will find communism actual operation. Only when civilization ambition desire for personal betterment have touched people find communism abandoned favor some other plan which gives scope individual initiative. That why the real reactionaries are the disciples Marx and Lenin. The true radicals are the men and women who insist that the capitalistic system has given more actual benefits and greater security for the average man within the last 400 years than did any and all other systems the previous 8,000 years. wonder America will continue the road progress even though CHARLES MOORE President, Moore Machinery Co., Los Angeles. Reprinted from July issue Moore Momentum Vol. 138, No. | WONDE 3 ° ° FRED PRENTISS Cleveland Editor, The Age ° TEEL tubing for boilers and other pressure purposes manu- factured the electric resis- tance welding process now nor- malized controlled atmosphere electric Steel and Tubes Inc., subsidiary Republic Steel Corp., its Cleve- land plant. This development production processes been made connection with the com- pany’s recent expansion program, which included the erection large extension its plant and the installation furnace and other equipment. The new struc- ture connected the main fac- tory building and used for proc- essing, storage and shipping. Before the installation the new furnace equipment, the tubes were normalized after welding ordinary electric furnace and then air cooled. Pickling re- move the scale followed heat treat- ment. produce tubing abso- lutely free scale without the IRON AGE, July 30, 1936 necessity pickling (although normalized above 1650 deg. F., the critical point the steel), and improve the finish and surface the product, the use con- trolled furnace was adopted. Incidentally, the plant kept free from the sul- phuric acid fumes that formerly came from the pickling tanks. The normalizing furnace said the largest controlled atmos- phere continuous furnace that has been built and one the first used for the continuous heat treating steel tubing. The advantages tube en- tirely free from mill scale both the inside and outside surfaces have long been -recognized. were possible obtain tube which the scale iron oxide covers the entire surface the tube with possibility that any the scale would chip off during installation resistant corrosion. Most steel boiler and other pressure tubes are formed hot, and scale produced during the operation. Such scale not uniform over the entire surface and this gives opportunity for selective corrosion pitting due the electrolytic action caused the difference potential between the iron oxide and parent steel. There also danger that such scale may cover and hide defects the steel. may removed pick- ling sandblasting some cases cold working. Many users, particularly among the util- ity companies, order boiler tubes with scale removed one these methods. clean sur- face particularly important when the tube used refrigera- tion equipment some refriger- ants have strong tendency re- move scale from the surface the tube, causing poor circulation the unit even actual ob- struction the line mechanism. TRIP steel moving through the continuous welding machine formed into tubular shape while passing through series rollers and the butt edges are welded together form boiler tube. — has long been recognized that uniformity, not only gage, but also diameter surface inside and out, and the microstructure and temper, are very desirable fea- tures boiler and other pressure tubes. The esses followed making electric resistance welded tubing produce product that seems possess all these essential features with high degree uniformity. The wall thickness, diameter and out- of-round conditions are held close limits and the inside and out- side the tube free scale. Microstructure the weld slightly changed and the tube slightly harder the point welding. The method which the tubes were made heretofore has not been changed. The Johnson continuous welding process followed, this including forming, welding and sizing immediately after welding. The metal hot rolled open- and then sheared both edges being passed through pair rotating circular shears assure tube the proper diameter. The variation the gage the strip any cross-section rarely exceeds 0.003 in. and subsequent opera- tions have practically effect the wall thickness, concentric tube assured. The strip cold formed into butted tube passing through series rolls and the formed tube then passes through series rolls and the formed tube then passes through the welding unit which joins the butted edges. The cold rolling action forming and sizing the tubes improves the ori- ginal high grade surface. Chemically the steel not al- tered the welding operation, be- cause the heat generated the resistance the butted joint the flow high amperage current and pressure completes the weld without the addition any extra metal. The amount metal ex- truded both inside and outside the tube very small, because the factors affecting the welding proc- ess, namely pressure, temperature, contact and speed, are corre- lated that they weld the edges the steel only and the heat does not penetrate into the body the metal. With the welding heat confined the edges the strip, the sur- face not affected the welding operation. slight burr upset formed the weld and this removed inside and outside the tube cutting tools. smooth surface the weld, one which virtually impossible locate the weld, produced the out- side the tube cutting tool located directly after the welding unit, which shaves off the outside burr. When the tubes were first made the inside burr was rolled forged down while hot rolls in- side the tube about foot from the welding unit. These rolls were shaft fastened the entry end the welder where the tube butted for welding. While this method removing inside burr could employed because the process continuous, im- proved method removing the as - largest controlled atmos- phere continuous normalizing furnace yet built, steel tubing produced free from scale and without pickling. The process operated Steel Tubes, Inc., subsidiary Republic Steel Corp., new plant structures which are part the re- cent expansion program. burr was developed little later. With the present method cutting tool used and the upset re- moved instead being rolled into the tube. The tube comes from the welder subjected all conven- tional expansion, flanging and flat- tening tests prior the finishing operations, after which again tested. also subjected the tests called for boiler tube spe- cifications. Periodic samples are roller ex- panded with standard roller ex- pander, after which the tube flanged. Test specimens are taken while the tube being welded and tests are made immediately. there evidence any failure the weld, the tube rejected and further tubing produced until adjustment has been made and good weld obtained. obtain uniformity micro- structure and has been the practice the TRUNITE electric welded steel tube showing the left the before annealing grain structure, and the right the after annealing normalized structure. THE IRON AGE, July 30, as-welded tube temperature above the critical points the metal which the case boiler tube steel 9.08 0.18 carbon 1650 deg. Normalizing com- pletely recrystallizes the steel, re- lieving all welding and cold work- ing stresses and producing fine grain microstructure uniform hardness. This heat treatment re- stores uniformity such ex- tent that virtually impossible locate the point weld under the microscope. This shown accompanying illustrations, which show the structure the as-weld- condition and the after normalizing. ordinary continuous electric fur- nace loose scale was formed which changed free surface the original cold worked welded tube. This neces- NTRANCE end the air controlled continuous ing furnace through which the tubes are carried live roller conveyor that extends through the blueing furnace indistinctly shown the far beckground, Tubes move through the normalizing fur- nace one layer assure their being heated uniformly, The hood above the furnace entrance carry away any unburned may leak from the entrance. sitated pickling remove this scale and produce uniform surface. The tube after pickling did not have quite the same fine dense cold rolled surface had before being normalized and pickled, although possessed all the essential features uni- formity gage, diameter, mi- crostructure and hardness and surface condition. preserve the fine finish and unless bright anneal desired, continue the conveyor from the normalizing furnace blueing furnace shown this picture, which they are given thin blue oxide coating rust preventive. 20—THE IRON AGE, July 30, 1936 : : the blueing furnace the tubes move along the conveyor into the processing room, the discharge end the conveyor being shown the left center. From the conveyor they are automatically dumped into racks and crane delivers them bundles the straightening rolls shown the right. surface which results from the strip well away with pickling the tubes after normaliz- ing, the controlled atmosphere con- tinuous electric furnace stalled. This unit consists the furnace proper ft. long and cooling chamber approximately ft. long, the atmosphere the lat- ter also being controlled. The fur- ENERAL view the new boiler building which the tubes ened and cut length, hydrostat- ically spected ciled and then are either loaded cars placed storage. nace roller hearth type, its width being ft. in. across the rollers. The cooling chamber water jacketed the top, side walls and bottom, that the cooling rate may controlled. Tubes which average around ft. length are carried through the furnace and cooling chamber live roll- ers the rate 5000 lb. per hr. reducing gas made par- tially burning illuminating gas passed through refrigerating unit remove all moisture and fed into the furnace prevent oxidation rate which always keeps the furnace and cooling above atmos- pheric pressure that all the leakage outward. This leakage burned both the entrance and THE IRON AGE, July 30, exit doors the furnace. Hoods with exhaust fans are placed di- rectly above the doors remove any traces incompletely burned gases from the building. Automatic temperature control- lers are used maintain the de- sired temperature 1650 deg. which has been found yield steel fine grain size and which, though ductile and easy roll, tough and uniform its phys- ical properties. The cooling cham- The normalizing furnace 620-kw, 220-volt, 3-phase unit and was built the General Electric Co. The tubes after normaiizing continue their movement the roller conveyor, are inspected and removed bright annealed sur- face required. Boiler and pres- sure tubes, however, continue the conveyor and are carried blueing furnace which light blue oxide coating imparted storage section showing the conveyor rack for handling and storing tubes, the use which results much saving floor space. ber sufficient length that with the desired rate cooling the tubes leave temperature below that which form. The result homogene- ous tube uniform grain struc- ture and hardness with all its original fine, dense and scale-free surface preserved. Boiler tubes standard boiler tube analysis steel from in. outside diameter and heat ex- changer tubing various grades steel from 3-16 in. in. out- side diameter are normalized the furnace. 22—THE IRON AGE, July 30, 1936 the tubes similar the blueing gun barrel. temperature 650 deg. maintained this furnace, which gas fired. Blueing the tubes, was thought, would provide some mea- sure protection against rust shipment and storage. However, the oven has not been use long enough observe the efficiency the coating throughout yearly cycle climatic changes, that evaluate accurately the effective- ness the blue oxide coating rust preventive. The tubes continue the roller conveyor from the blueing oven into the recently completed boiler tube processing building. This arranged nearly possible for straight line production with minimum amount handling be- tween operations. Tubing han- dled bundles almost entirely overhead crane. The processing operations start with straightening, the crane car- rying the bundles tubes directly across the building straighten- ing rolls. Although the tubes are fairly straight when discharged from the furnace, they are run through the roll straightener assure product that will meet strict requirements. Ends suitable for roller expansion lengths tubing are secured trimming both ends each tube lathe. They were originally cut the approximate length di- rectly the welding machine with punch cutting device that synchronized with speed, making unnecessary stop the welder each time tube cut. Each tube after straightening pressure 2,000 per sq. in., while two air hammers play upon it. The weld kept top and inspector whose only duty in- spect the tube during testing keeps close observation the tube. The tester was specially designed and practically automatic opera- tion. tube rolled from the feed- ing skids into the tester and all further operations are automatic, the through levers one man. The ends are first closed, then the tube clamped position, filled with water, valves closed and the requi- site pressure applied. the com- pletion the test the reverse oper- ation takes place and the tube discharged. The requisite number flang- ing, flattening and crushing tests are made each lot accordance with the specifications the A.S. M.E. boiler code customer’s specifications. Each tube then given visual inspection for surface according A.S.M.E. specifications. The requi- site number test pieces are taken certain that the run meets the physical tests specified the various codes. After inspection completed the tubes are stenciled and directly cars spotted track within the building are carried the crane farther back the building for storage. The storage racks are par- ticular interest they provide not only facilities for storing but also (CONCLUDED PAGE 80) a AMP salt air plus the by-products combustion combine make New York atmosphere severe taskmaster metal roofs. One the interesting developments meeting this situation the employment Monel has been used with satisfactory results this district the New erecting York public library, the Pennsylvania terminal and other build- ventilator exhaust the roof the Museum Art. ings. Most recent adaptation Monel roofs that shown these pictures applied the Brooklyn Museum Art. LEFT view skylights and roofing the Brooklyn Museum Art. Monel plays large part this construction, even the nails being that material. BELOW cap flashing being applied the new museum roof. THE IRON AGE, July 30, 1936—23 >. | om ° DIETERT Chief Engineer, United States Radiator Co. MOLDING sand the foundry most essen- tial. However, sand handicaps the foundry when the melter fails exercise most care- ful control over its many variable properties. Sand testing equipment now available which will enable foun- drymen control molding sand within certain range required for the production high-quality cast- ings. The purpose sand control obtain and maintain desirable moisture content, permeability, green and dry strength, expansion, deformation, sintering and fineness. After suitable workable sand obtained, the maintenance uni- form sand will more set productive routine than any other procedure available the trade. Forcing molders work with sand that varies from day day makes impossible for the molder the foundry personnel set stand- ard routine practice which essential modern production quality goods. system for testing molding sand foundry required de- termine the exact condition the 24—THE IRON AGE, July 30, 1936 sand. Sand testing may incor- porated the foundry routine with very little effort, and the outline which follows the usual pro- cedure: (1) Number each sand floor sand system. (2) Collect representative quart sand samples from the front, center and rear each sand floor from each sand system every hour. (3) Test sample for moisture. (4) Test sample for permeability. (5) Test sample for green strength. (6) Test mold for mold hardness. (7) Test sample for dry strength once each week. (8) Test sample for clay content and fineness once each month. Test Data Application Figures obtained from testing sand are value only when the data are compared with castings produced. outline method applying sand test figures given below: (1) Record test figures. (2) Compare test data with the castings produced. (3) Compare test data with the castings produced and with the floor system producing the best cast- ings. (4) Set sand test figures that produce best results. (5) Condition the sand close these test figures possible order reduce fluctuation sand char- acteristics. (6) Maintain standardized mois- ture. (7) Maintain standardized perme- ability. (8) Maintain strength. (9) Maintain standardized mold hardness. (10) Maintain standardized fine- ness. has been repeatedly demon- strated that controlled molding sand will reduce scrap loss and im- prove casting quality. Production increased uniformity and good working sand. Supervisors are relieved the constant worry OUNDRYMEN must bal- ance refractoriness, po- rosity, grain size, strength, temper and binder sand nicety they expect best casting results. Patently there are many variables, and not surprising that quite few melters neglect some factors and apply uncertain rule-of-thumb methods their sand conditioning seek remedies. All these cost savings can not fail reflect the financial condition foundry. Moisture Control Molding sand may obtained factured material. always re- mains the foundrymen’s task add water the sand make suitable for use. Upon the amount water added depends whether the sand will practical value. Moisture con- trol the most important step the preparation sand for mold- - = FOUNDRY ing. variation “points” will cause the sand function entirely different material. Such moisture variation, besides causing defects, reality the same furnishing unfamiliar new sand the molder. Due molder’s inability feel exactly the moisture content methods. this article, the author reviews the need sand control, and points out the influence each sand characteristic the physical properties casting. This manuscript late February before the Birmingham section the A.S.M.E. with the cooperating. sand, some form testing equip- ment necessary. Through the use Moisture Teller, quick and accurate moisture test pos- sible. Sand moisture should deter- mined the time mixing. De- terminations the rate one per minute may made with the use Moisture Teller (made Harry Dietert Co.). great variety casting defects result from moisture variations. Defects termed “washes” are those caused the sand being low moisture. Low moisture results low dry sand strength, and this causes the sand lack firmness when molten metal flows over it. Should the moisture high, large amount steam formed when the molten metal lays against the mold surface. The edges the casting contour may poorly de- fined and the surface will contain blow holes. When the moisture content very high, large blow holes with jagged edges will result. The finish casting marked- influenced the temper (mois- ture content) the sand. sand tempered the dry side will cause the surface the casting con- tain areas irregularly shaped de- pressions. Sand tempered with in- sufficient water will eroded molten metal due its low dry sand strength. sand tempered with excess moisture causes many sand grains stick the pattern, which re- sults the appearance void spaces the mold surface into which molten metal will flow. rough casting surface results. Sand that correctly tempered will pro- duce the smoothest casting surface finish. Temper molding sand may best controlled continually determining the moisture content the sand mixed. Test figures thus obtained should used govern the amount water added. Fineness—Permeability Molding sand grain size defines the weight casting that should molded the sand. addition the size the various sand grains, the variety the various grain sizes and the quantity the various grain sizes, designated distribution, are great impor- tance. Grain fineness and distribution largely determine the permeability molding sand. Equipment used quickly determine the permea- bility sand consists rammer for preparing standard specimen which subsequently tested permeability meter. The permeability sand governed the quantity and dis- tribution the fine small sand grains, i.e., from 200 mesh pan material. Grain size and distribu- tion are determined sifting sand through series sieves shown Fig. First thought may suggest the use sand possessing high per- meability well the safe side. This good practice, though may the source casting defects termed “pin holes.” combination high permea- bility and high moisture may pro- duce casting whose surface con- tains large number pin holes. Each pin hole small void space caused steam pocketed the molten metal arising from the fact that the moisture the sand flash- steam. The rate which steam generated the mold in- creases the permeability creases. reduction permeabili- moisture may eliminate pin holes steam origin. The other extreme would use sand possessing permea- bility too low for the weight metal. Casting defects caused low permeability are termed THE IRON AGE, July 30, 1936—25 = 5 we q “blows.” large pocket steam may hold molten metal away from the mold surface. remedy this, the permeability should creased. Occasionally the permeability sand slightly the low side with the result that when the mold rammed little too hard the cope side, where ferrostatic pres- sure the least, sufficient steam pressure formed cause the molten metal agitated. This agitation the molten metal erodes the mold surface, causing casting defects termed “seams.” The reme- increase permeability. The finish casting depends largely the fineness and distribu- tion the sand. sand high permeability will give rough peb- ble casting surface the point where the molten metal will pene- trate into the sand. reduction grain size will usually increase the smoothness casting, par- ticularly when certain grain sizes are removed that are much coarser than the average grain size. reduction the variety grain size increases the permea- bility. sand can, therefore, much finer for given permeabili- when distribution small, thus giving best finish for the chosen permeability. The fineness permeability sand can controlled best us- ing new material which possesses fineness and distribution de- sired the shop molding sand. This reduces the constant struggle maintain the permeability the sand its chosen value. The reduction fineness air suction shakeout provides excel- lent shop control the fineness. Strength Control The strength molding sand must considered first strength the green tempered state, and, second, the strength the dried state. The green strength molding sand the ability the sand hold tegether when the mold lifted from the pattern and when the mold closed and transported. also adds the sand’s ability hold its molded contour the fer- rostatic pressure the molten metal tends distort the mold sur- face. The dry strength molding 26—THE IRON AGE, July 30, 1936 sand must present soon the moisture the sand evapor- ated either mold oven the heat molten metal. Should sand grain size and distribution can determined sifling the sand through series sieves similar the ones shown here. the molding sand fail possess in- sufficient dry strength, the sand would easily washed the molten metal. The green strength molding sand secured normally clay substance, and the quantity and quality the clay substance are the controlling factors imparting green strength. is, therefore, practical value determine the percentage clay substance with rapid sand washer, illustrated Fig. The actual green and dry strength, produced the clay sub- stance such cereal binders may added, can determined using sand strength machine, The casting defects most com- monly caused low green strength are drops and swells. The casting defects which result from high green strength are, sand burns, rough finish and high clay content will reduce the sintering point and flowability the sand and will result rough casting surface finish. low dry strength, such may caused insufficient quan- tity plastic clay substances, will responsible for casting defects which are termed “dirt inclusions,” “cuts” and “washes.” Most fre- quently, low green strength the cause low dry strength that the dirt inclusions and wash defects are ascribed low green strength. The green strength sand may controlled establishing uniform daily addition new sand bonding material, such clay Bentonite, the used molding sand. The quantity new mate- rial added adjusted when re- quired order maintain established green strength. The dry strength sand may controlled selecting new sand, clay Bentonite which pos- sesses the dry strength properly de- sired. The addition cereal bind- ers, sea coal and molasses sugar also furnish means controlling dry strength. Expansion-Contraction Control The expansion and contraction molding sand are determined subjecting in. diameter sand specimen various temperatures. The variation the length sand specimen measured and ex- pressed expansion contrac- tion per inch sand specimen length. mold made from sand with high expansion will show cracks the surface, illustrated core the left Fig. The core the right the same illus- tration made with sand low expansion. Molding sand, like any other ma- terial, expands when heated. The expansion molding sand begins wal — | approximately 300 deg. and ends approximately 1200 deg. yond 1200 deg. some sands may be- gin contract while other types may remain their expanded vol- ume until temperature high 1800 deg. reached before begin- 1900 deg., molding sand begins contract rapidly, due the fact that portion the clay bond sinters rapidly this temperature. 3—Molding sand specimens after being heated 2500 deg. The specimen the left has high expansion characteristics and the one mass shorter. This change length termed the de- formation sand. Deformation measured thou- sandths inch decrease length per one inch length. The deformation new strong- bonded molding sand may high 0.080 in. and for weak sand with low moisture may low 0.010 in. Molding sand with high de- the right has low expansion characteristics. The expansion and contraction molding sand are influenced large extent the physical prop- erties and the mold hardness. Many casting defects are caused excessive expansion excessive contraction. rat tail defect ona light casting caused high expansion 0.020 in. Where the section casting heavy, suf- ficient heat present cause the sand first expand and then con- tract and cause scab. The control expansion and contraction materially resolves the reduction expansion and con- traction inasmuch low expansion and contraction are desirable. The available methods reduce expansion and contraction are follow: (1) Reduce moisture. (2) Increase grain size. (3) Reduce ramming. (4) Reduce clay. (5) Increase combustible material. Deformation Control Whenever load applied molding sand, the shape the mass sand changed. com- pression load will cause the sand 2—Clay substance con- green The percentage clay sub- stance determined with this type rapid sand washer. formation per unit load will tend produce swells. will also con- tribute drops, due the fact that flask twist will tend crack and weaken the sand. Crushes may also caused increase number when the de- formation low. This due the fact that the sand not capable deforming sufficiently take the crush the mold. Considerable research required thoroughly understand the meth- controlling deformation. Sintering Point Control The sintering test offers the best method available for testing the 4—The specimen the left high flow- ability (90) and the right specimen low flowability (56). Low flowability encourages the formation voids. ability molding sand with- stand sand burn. high sintering point will much improve the finish castings. The sintering point sand may increased follows: (1) Increasing the grain size. (2) Increasing the mold hardness. (3) Reducing the clay content. (4) Reducing the fluxes. Flowability Control The flowability molding sand may visually determined ap- proximately may deter- mined exactly flowability indi- cator attached sand reamer. sand with low flowability will show large number open void spaces, while sand with high flowability will present apparently voidless mold contour, shown Fig. high flowability one the essentials the production smooth casting surfaces. High flowability may obtained the following procedure: (1) Decrease green strength. (2) Decrease grain size. (3) sea coal. (4) Temper the sand either dry heavy side. THE IRON AGE, July 30, 1936—27 4 # 4 & Me : tee aq its earlier experience the automotive field, was natural for the Briggs Manufacturing Co. Detroit, apply "conveyor line its new pressed steel bath tubs and kitchen sinks. These pictures show some the steps used turning sheet steel into modern, light weight tubs and sinks. 4 acid resisting enamel mixture sprayed the prepared stampings means spray gun operated com- pressed air and utilizing overhead conveyor system. preparation—pickling—follows sequence seven dips. First alkali solution, next two water rinses, then sulphuric acid immersion followed water wash and neutralizers. 28—THE IRON AGE, July 30, 1936 ser d t 4 RIGHT FTER the tub drawn from the sheet, utilizing some the largest existing presses, the surface must roughened that the enamel will adhere permanently. This done modern, overhead lighted booths with adequate ventilating systems. coats enamel are applied addition the ground coat. Each one “burned on" gas fired ovens 1500 deg. Here see procession tubs going the ovens. LEFT ODERNIZATION keynote all through the process will noted this picture which shows gas fired oven and its electrically operated loading machine. THE IRON AGE, July 30, 1936—29 4 4 ; 4 - <4 4.6 doors opened and the grill work above the entrance. 30—THE IRON AGE, July 30, bronze gates that stand the hall. THE ornamental bronze work the new ar- chives building Washington out- standing example artistic han- diwork metals and has elegance appearance that har- monizes with the beautiful struc- ture that design and construc- tion one the distinguished architectural achievements the Capital City. The bronze work also conspicuous because the size and attractive appearance doors and gates that have been installed the building and the amount money involved the construction these highly deco- rative embellishments. All the bronze work building was fabricated and in- stalled the John Harsch Bronze Foundry Co., Cleveland. The ex- tent the use bronze the finishing the building cated the contract price for the bronze work, which was $250,- 000. This included, addition the doors and gates referred particularly this article, small doors and gates, grills, stairway railings and other decorative work bronze. The main entrance the build- ing guarded two massive 5 exterior view the Archives Build- ing. doors which are said the largest bronze doors They are ft. high, ft. thick and each ft. wide. Each weighs structed steel sections welded and riveted together. Extreme accuracy was required fabricating the cores, which carry the entire load and rigidity was also essential or- der that the doors would always hang plumb. The doors are built in. bronze plate, extruded bronze sec- tions and bronze the lat- ter being used for numerous ro- settes that give decorative effect and for trim. The face made two plate sections ft. long and welded together, the seam being massive doors ground and polished that the joint cannot seen. fact, there Ib. the face edges. The bronze plate placed the en- fastened the core with invis- trance the build- ible screws and the rosettes are ing. attached the plate screws cast the back the rosettes. The doors slide forward and backward and out pockets the building wall either side, overhead track and through he THE IRON AGE July 30, 2 v 4 | 3 groove the sill the bottom. Each door operated 5-hp motor with push button control. Crating the doors for shipment prevent their weaving while be- ing moved the train presented quite problem. For this purpose heavy strong steel crate requir- ing tons steel was built and prevent sliding the car the crate was fastened the Massive highly decorative bronze gates stand the entrance the exhibit hall which the Consti- tution the United States and other priceless documents will preserved. These gates extend across entrance opening ft. in. wide between two walls the building. harmonious color effect provided the use three non- ferrous materials the fabrica- tion the gates. The gates are ft. high and have four posts the supporting member. Two gates swing from the two interior posts, the two outer sections the gate assembly being stationary. The posts are extruded bronze in. diameter and the spindles used constructing the gates are white bronze rods in. and in. diameter. The bottom rail bronze, this being hollow permit the insertion the lower ends the spindles. Medallions that decorate the tops the gates are white bronze inlaid with yellow brass. The spindles are capped with white bronzed spears. American eagle cast from yellow brass mounted the top each the four posts. The construc- tion these gates required 6000 lb. brass and bronze. Each post mounted over in. diameter steel pipe that ex- tends from the top the post down ft. in. beneath the floor. Below the floor reinforced con- crete column built around the pipe. These columns provide rigid support for the posts. When the gates are opened and closed the adjoining posts which they are attached move with the two movable gate sections, the section the pipe that extends through the center the posts serving shaft, which the post rotates. assure easy movement the gates they are mounted ball bearings. The archives building was erect- the George Fuller Co., Washington. John Russell Pope, New York, was the architect. 32—THE IRON AGE, July 30, 1936 OULDER DAM, with its vast system heavy machinery, has been immense consumer steel. Recently purchased units for the dam are 72-in. 60-ton needle valves now being made Thomas Spacing Machine Co., Pittsburgh. Some 570 tons steel and 150 tons bronze will used the valves. The two main housings for each valve account for approx- imately 75,000 steel, and each bronze needle body weighs ap- proximately 10,000 Ib. The 40,000 sq. ft. floor space devoted production these valves arranged that three units are progress production one time. Many operations are vidual parts each valve prior assembly. The two steel housing sections and the bronze needle body are each put through three major tooling operations. steps they are worked the bor- ing, milling, and drilling machines. These three large parts alone re- quire the drilling cast steel nozzle one the 60-ton needle valves the process being bored preparation for placement the valve liner, which guides the 20-ton moving mechanism when operated. : | ‘ ranging size accommodate Special jigs were made aid all drilling operations. These jigs were used insure that the holes all mating parts would fit cor- rectly. The largest ring-shaped with outside diameter 138 in.; the others, all, varied size and shape spit the many parts drilled. total 540 bolts and studs, many which are specially heat treated, are used joining the 125 parts which into the assembly each valve. All valves are completely assem- bled the shop floor, after which they are placed operation and run through their full movement. one test, the valves are operated under pressure 400 per sq. in. insure that all parts will ACING the end the bronze diaphragm tube, one the each the twelve 60-ton Boulder Dam needle valves. This one many ma- chining operations required the job. The tube in. long and has out- side diameter when finished. the bronze needle body for each 72-in. needle valve delicate operation. worked machine using wide tool eliminate tool marks, and final finish imparted with emery cloth. This part the valve in. long with outside diameter in., and machined thickness in. withstand the punishment bi- passing 25,000 gal. water per min. velocity miles per hr. The valves will installed two batteries six each the 2-ton tunnel plug outlet works lo- cated, respectively, the lower Arizona and lower Nevada pen- stock tunnels Boulder Dam. THE IRON AGE, July 30, 1936—33 4 ° ° ° FRANK OLIVER Detroit Editor, The Iron Age ° ° ° HEN because expanding business, executives Me- chanical Handling Systems, Detroit, decided more than double its floor space for manufac- turing, they incorporated num- ber ideas keeping with good layout. the same time unit system was devised take care future expansion along logical lines. the present development, the original building was lengthened ft. and two bays were added, one stock and machine shop bay ft. wide, the other work assembly bay ft. wide. The plan make future extensions the basis 40- and 60-ft. alter- nate bays. The 40-ft. bay high enough that additional floor for dead storage can added such space needed. The company’s principal prod- ucts are equally divided between industrial conveyors and “haul- away” trailer units for transport- ing automobiles over the highways. Both products are fabricated from 34—THE IRON AGE, July 30, 1936 ACHINE shop and stock room, with chine deck and bus bar casing the background. This central bay high enough provide for extra floor for dead storage space needed. structural shapes and variety special shapes formed from plate the press brake. Both riveted and welded construction are em- L-form material flow has been adopted; that is, material— mainly structural shapes, plates west side yard, heads east through shear, friction saw, and punch and sent south down either two work bays right angles. The building steel and steel sash construction, with only low wall brick running window height. Roof wood, tar paper covered. There are columns be- tween bays and Austin roof truss, electrically welded, spans the 60-ft. bay. Incidentally, the original building the same de- sign and was the first welded in- dustrial building erected Detroit. 5-ton underhung crane 40- ft. span suspended directly from the roof trusses. The bridge the struction that the crane trolley can run directly off monorail traversing the ends the bays line with the material flow east. Such arrangement feasible since none the haul- away trailer units taxes the crane capacity. Because the assembled product often runs ft. overall length and must driven away, large doors ft. wide ft. high are provided the end each bay. tion ample, fact brilliant, the glass encased walls, but high- intensity mercury vapor lamps al- ternating with filament lamps pro- vide the necessary foot candles late afternoon and night. Since great deal electric welding performed the fabri- cation the product, the provi- sion for adequate welding facili- ties was paramount. The company has generator sets, which are set two mezzanine cat ORTABLE welding generator sets are mounted up- per deck out the way stock piles and finished work. Connecting switch boxes are mounted directly the bus bar distribution cas- ing and control each set from central panel board. SUIT THE walks suspended from trusses along the line bay col- umns. Ultimate capacity welders per deck. This arrangement accomplishes three purposes: gets the weld- ing machines out the way where they are not subject abuse having stock piled dropped them; keeps them cleaner, and simplifies the connections. Power bought from the local utility and comes Transformers outside the building cut this down 220 volts and dis- tribution through bank oil Power for the welders passes through 800-amp. switch three copper bus bars in. These bars divide into two chan- nels and are encased 18-gage steel trough painted with alumi- num. Removable covers are placed intervals, which permits knife switch boxes installed for flexible conduit connections each welder unit. Control the bat- tery welders separate rheo- stats mounted central board the wall. Welding current supplied through standard rubber- covered cables present, but ulti- mately the intention bring these connections strategic points conduit the floors. Troughs are already prepared the concrete receive these con- the end one the weld- ing machine decks, the bus bars enter panel board from which the power distributed the va- rious machines, pipe conduit the floor (as for the press brake, shear, etc.) and the air the small machine shop. Flexible B-X cable connects unit heaters separate conduit distribution sys- tems. Each heater thermostatic- ally-controlled from point about head height from the floor. Shop deg. winter. Incidentally, the expansion program boiler installation with automatic stoker was made the heating plant, which the motor-driven air com- pressors are also housed. Another novel feature this layout the location the super- intendent’s office what amounts pulpit ft. above the floor. With glass walls all sides, can view all parts the shop merely rising from his chair. the same time the office well lighted and relatively free from noise, considering the usual din structural shop. There blacksmith shop used principally for simple forging op- erations and for hot bending beams, channels and angles. separated from the rest the shop corrugated steel partitions, and its outside walls are the same ma- terial. For hot bending operations there are two portable forge fires mounted casters and capable heating 6-ft. section in. width. Coke used the fuel, and the blower mounted integral with the unit which itself built structural shapes welded around the brick work. Such arrange- ment adds flexibility the opera- tions when awkward shapes are encountered. Most the bending performed tables with hand tools. _THE IRON AGE, July 30, 1936—35 | 3 4 f Auto production shows gain over previous week when hot weather curtailed schedules. Small car market being watched Big Three Willys shows signs strong comeback. ° Shortage skilled workers handicaps both ma- chinery builders and tool and die shops. Unionization drive making little progress, and industrialists’ fear trouble this fall seems un- founded. July 28. upward turn last week, although reality the rise rather reflected the fact that the previous week production had been curtailed slight extent owing excessively hot weather. Ward’s Automotive Reports esti- mate total production for the week ending July 99,329 cars and trucks the United States and Canada, compared with 97,768 the previous week. year ago the cor- responding week’s production was approximately 81,490 units. In- creased activity General Motors and Chrysler groups accounted for most the rise, Ford Motor Co. holding its own for the past three weeks. This will probably the final turning point from the hundred thousand unit mark. Although as- 36—THE IRON AGE, July 30, 1936 semblies will continue fairly high level throughout August, sea- sonal shut-down and change-over periods will reflected the ex- pected decline this time the year. Ford Motor Co. shuts down for inventory for its usual two weeks beginning Aug. that during that period total production will reduced approximately 24,000 units week. under- stood that Chevrolet has scheduled approximately 100,000 assemblies for August, but shortly after the first the month the motor plant will shut down for change-over. All the assembly plants will have been supplied with motors and other components, including stamp- ings fabricated during July. Plym- outh, which has very small change-over program sight, will continue its present output ap- proximately 12,000 units week for indefinite period, long present sales continue. Furthermore, large bank motors being built since motor changes are contemplated 1937 models. Change-over work already going high rate several the independents the industry and the staggering announcements anticipated will not permit the total volume produc- tion for the industry reach low comparable with last year’s September. fact, this year will have situation where three four manufacturers will an- nounce ahead show time and where others will find themselves only with dummies exhibit the show place running models. This owing the delivery situ- ation the machine tool plants, situation that has been further aggravated the extremely hot weather recent weeks. Total output cars and trucks the United States and Canada for June, reported the De- partment Commerce, was 470,- 887 units, only 10,000 under the May figure. April represented the high point the year, with 527,- 728 units. The corresponding figure for June, 1935, was 372,085. Pre- liminary reports indicate that new passenger car sales du