The Iron Age 1915-11-11: Vol 96 Iss 20

New York, November 1], 1915 ESTABLISHED 1855 VOL. 96: No. 20 Machine Design in a Rhode Island School Practical Shopmen as Instructors to Produce Designers and Draftsmen Who Will Be Ac- quainted with Standard Modern Shop Practice BY W. E. FREELAND A Rhode Island business man who desired to place his son with one of the well-known manufac- turers of machinery of his home State was given this advice: “Give your boy three years at the Rhode Island School of Design and then send him to us. His training there will help him to grow faster with us.” This statement well expresses the attitude of the local machine builders toward this Providence school which was founded in a small Zround floor is equipped as a machine shop and ~ he upper floors for the teaching of drafting a: hematics. All the work is individual and and Is _Class work in either the day or night te Ss that a student has a chance to advance “aSt as his ability will permit. True to its name 1105 to consider himself as a designer when he receives his diploma; that he has only acquired the foun dation and that he must build thereon a structure of practical experience. Students in the day courses are received on indi vidual judgment of their fitness for their chosen vocation and are usually of preparatory school age. The night classes are composed mostly of mechanics who are seeking a better or a special education explain the somewhat unique standing of the school in the estimation of employers. The head of the department is John A. Taudvin, for eighteen years with the American Screw Company and now con- sulting engineer of the Eastern Bolt & Nut Com- pany. Baxter R. Waldron, for thirty years with and purpose, every effort is made by the school the American Screw Company, is in charge of the to deve any special aptitude of a pupil as a machine shop, and Annie ©. Clark, Ph.B., Brown designer, but in the instruction special emphasis University, is teacher of mathematics. With the 8 place the fact that no student has the right night students, Mr. Taudvin has charge of the ad- eg alge aR Pett RE Ng mn ty ws A ‘ 7 ; : S Work and Drafting Are Studied in Relation to Each Otl to I rs} M Desis : Way over thirty years ago. It also finds generous Some of the boys in the day courses are sent to the ; Support in numerous scholarships given by the school by their employers and the work done in f State and the city of Providence. The director of the school counts on their apprenticeship record. the school is L. Earle Rowe. One of the results of the past record of the school The mechanical department has an enrollment of is that but few of the Rhode Island manufacturers 35 day and 160 night students. At the open- now take apprentices into their drafting rooms, pre- : ing of the present school year this department ferring to employ graduates of the school or to I moved into a four-story building with about 15,000 send selected boys to the school for training. i 8q. It. of floor space available ivr its purposes. The A glance over the list of instructors helps to f ~ 1106 THE IRON AGE Novembe vanced pupils; Z. R. Tucker, head of the apprentice department of Brown & Sharpe Mfg. Company, has charge of the intermediate pupils; and Jacob C. Millard, designer of jigs and fixtures at the Brown & Sharpe Mfg. Company, has charge of the begin- ners. J. P. Burdick, a graduate of the Massachu- FF 0 b.- /4-B Linkwork In Brea hearers let A-6-8-4 C-/0—D-4-£-3° Power 1 nel shaft F which turns 1 times as fast «4 G _— rBs Large theel DE cccrieshitiiiocn oa Three views c 2p : parent detail _— setts Institute of Technology and connected with the Brown & Sharpe sales department, teaches mathematics. Four other assistants are employees of the same concern: Benjamin P. Graves, designer of milling machines; John W. Parker, tool designer; Charles M. Morrin, designer of safety appliances; and W. H. Margerison, machinist. The latter is assistant to Mr. Waldron in the machine shop. The work of the students in the first year is largely in the direction of securing a thorough knowledge of mechanical drawing and the subjects taught are freehand drawing, construction prob- lems in plane and solid geometry, orthographic pro- jections, development of surfaces, intersections, isometric projection, perspective, screw threads, bolts and screws, springs, cam design, lever design gear design, sketches, assembled and working draw- LINK AND LEVER CONNECTIONS R. 1. SCHOOL DESIGN WS.BAKER MAR 16, /9/5 L/NK OR ROLL RUNNING FIT LINK OR ROLL RUNNING FIT _ NY ar | PIN/44g WASHER = \COUN = NO. / NO. 2 LINK OR ROLL } Lojeiw } J 4 \ . \ / * f “| LEVER ~ LEVER NO. 3. NQ 4 | , LEVER 4 LEVER LINK OR ROLL LINK OR ROLL | RUNNING FIT RUNNING FIT V4) & Y COUN TERBORE PIN K ni K N —" ee NO. 6 aes viii Sciadioapennieaineditniall Blueprints Covering Details of Parts ings, shop arithmetic, algebra and shop school performs a notable work for em; send boys to the school by weeding ov or those who through mistaken ambiti: wisely selected mechanical drawing as tion. Ir the two following years the wo) problems in mechanical movements, the g resentation of forces, problems in shaft ings, couplings, pulleys, belting, rope-dr ing, levers, jig-work, patent-office draw plete designs and working drawings of gines and boilers, economizers and chin n- cluding with the design of a machine for a giyey purpose as the basis of a thesis report. there has been added an evening class in ji; and tool design for draftsmen or advanced student who have satisfactorily completed the elementar work. In mathematics the students are taught shy arithmetic, cutting speeds and feeds, pulley speeds and gearing ratios, lathe change gearing, change gears for milling spirals, milling machine indexing use of formulas and diagrams, angles and angular measurements, figuring tapers, horsepower of | ing and shafting, principles of levers, algebra geometry and trigonometry. When a pupil enters the school he ately started on shop work, of which least 5 hr. a week during his three years’ course This gives him a practical shop experience desirable in a draftsman. In his third year the given special instruction in pattern making in the woodworking division of the normal arts depart- ment of the school. The more advanced students frequently find opportunity to work part time in the plants of local manufacturers, thus their stock of practical experience. PROPORTIONS OF LEVERS R. t SCHOOL DESIGN W S$. BAKER MARIQ,19IS. ae - lo— J+ dj . : | “3? fan | Se | ec e J { nd cnajuaniiguens | A 8 .. 2 - 7 ¢ G inwecrna “SAtZ"| SB |.8/2B| 66D | 3750 66F Larceeno /SAtE | 7D | -— ~ ] rT eo * j ZEST sues) SI er aan i YOKE-ENOS Kae / - aK or r . &, VUtal CS, ear. ZS, Ccom- ? ‘ . Steam ep. neyvs [his Vear g, fixture he has student adding t wT 2h htt a UP ee ho ee M \SIZESTU LSH4+L) SIT | 66F | SY qk | 6251) i as = — = cecil Are Referred to in Evolving the Design November 11, 1915 THE IRON AGE 1107 / \ bo : } \ / Student’s Drawing of the Con three of the third year pupils are made the machine shop and a boy in his ear is given a first-year student to instruct the various machine tools. It has | that this experience helps the advanced rystallize the knowledge that they have and make it serviceable. It has been trated that the beginners advance much learning to operate the machines partly by another boy than they do vnen taught wholly by an older instructor. \ll the turning or other machining work is on rk, never as an exercise. In this way of the boys is held at high pitch by to their constructive instinct. At this students are engaged in building two | to the equipment of the machine e last half of his second year a boy nk together his work as a draftsman hinist, for at about that time he begins t parts that he has himself designed and actual experience some of the things ner must recognize and ever keep in s to do his share in keeping down + SLs the school to teach its students to nasized by the material furnished as problems in mechanical drawing. In the linkwork problem shown in the illus- data given the student comprise a ziving dimensions and speeds and two vering proportions of levers and link nnections. In this instance both of ts contain data based on the staridard the Brown & Sharpe Mfg. Company. indexing milling machine and an pointing machine designed by ad- Ss may be mentioned as examples of and skill exercised. e additions to the school plant now ‘ new building to house a power plant. tr + Here will be installed two 250-hp. Keeler dutch- oven boilers, a 160-hp. Ideal Corliss valve engine, an 80-hp. Ideal simple side-crank engine, dynamos and other apparatus. When the power plant is completed the advanced students in the mechanical! department will be given practical work to familiar ize them with power equipment, both steam and electrical. A Rhythmical Market Repor The market report of Rogers, Brown & Co., Cincin nati, dated Oct. 23, shows a state of rhapsody, th writer evidently having had a visitation of the divins afflatus since activity began to be felt in the iron trade The report is as follows: This week has been the best we have seen since leaves began to lose their green; the tonnage placed wa good and big, and covered all the grades of pig iron t be shipped throughout the land, showing progress on every hand. Good inquiries are floating ’round; $11.50 iron cannot be found. Steel makers inquire for price, and soon will close for a good big slice of basic iron for first half use, making that grade as scarce as goose (teeth) The stove foundries without fear continue climbing in low gear, and now the malleable shops, too, have ceased to mope and feel so blue. They’re buying iron to meet demands, for railroad buying still expands Chicago, where two weeks ago everything was deadly slow, is now almost the brightest spot, skipping along at a brisk trot. Last week a raise of seventy-five with out pause was eaten alive. Another good big jump ir price was this week gobbled in a trice. In fact, last week it was noted that higher prices were quoted just about universally because of the broad buying bee Low phos. aviates week by week; silveries higher levels seek: southern Ohio went up, too, but these are only a few of those who gradually are getting prices back up to par. Coke also is in good demand, with prices up on every brand. The future for all appears bright as better times disperse the night of depressed business, and it looks like all will soon fill order books. oe ee 2 aE gerene = yee 1, General Electric Practice in Sherardizing Electrically Heated Drums and How They Are Operated—Details of Salt Spray Test to Determine Life of the Protective Coating In the sherardizing plant of the General Electric Company, Schenectady, N. Y., the drum used is of It is rectan- The driv- the electrically heated revolving type. gular shape and is mounted on pedestals. Sherardizing Drums Having the Electric Located on the Top, Bottom and A Battery of ing motor is mounted on one of these pedestals and is geared to the drum through a reduction worm gear. At the present time two sizes of drums are manufactured, one having inside dimensions of 24 x 24 x 40 in., requiring 50 kw. to bring it up to the desired sherardizing temperature and 15 kw. to hold at that temperature, and a smaller one having in- side dimensions of 10 x 10 x 17 in., requiring 15 kw. to heat up and 5 kw. to hold at correct temperature. The heating elements are placed on each of the six sides of the drum and current is supplied to them through three collector rings at one end of the equipment. The connections are such that the drum can be operated on a three-wire direct-current circuit or a three-phase aig coger current circuit. The only change necessary for the latter circuit is to leave off one of the wires leading to the three- pole double-throw switch employed. The dust used in the process is Graselli zinc dust. View of One of the Drums Showing the Collector Rings Current to the Heating Elements at the Left, the Hopper Contents Are Discharged in the Center and the This is run through a magnetic separator at least once every four weeks to take out superfluous small particles of iron which are apt to become lodged be- tween the jaws of cotter pins, etc., and thus cause 1108 trouble in assembly. way the mechanical centages of iron dust in the coating vented. Heating All Four Sides Supplying the Into Driving Motor at the By cleaning the dust in thi, incorporation of large per- : al SO pre. It is recommended that the weekly analysis of working dust show the iron oq. tent. zed For each different heat 400 Jb, of pie dust are used with the larger drum, This consists of 360 Ib. of used dus and 40 Ib. of new Graselli dust. This 0.0] dust is mixed in tumbling barrel o pos sherardizing drum and sifted through per an 80-mesh riddle before charging the ter drum. Once a week the used dust js mixed in a sherardizing drum and then sifted, and from this samples are taken for weekly chemical analysis, To obtain the best results, ma- terial to be sherardized must have a clean surface, free from scale. rust, oil or paint. This is accomplished | pickling, sand or shot blasting, the last Elements r hour Deposit pe Inches - 200 240 280 320 360 400 440 #0 Degrees C. Relation Between the Temper Depth of the Met Chart Showing the ture of the Drum and the Coating being much to be preferred. Material must be packed in the drum in such a way that no violent tumbling Ww! occur or else sharp corners ane threaded parts will be dama aged neither should it be packed too tight!) or a free flow of dust and heat will not result and consequently poor sher- ardizing will be obtained. By actual experience it has been found that 400 lb. of dust to any load, ranging from 400 to 1800 Ib. of material, can be use When small material is packed in dividual receptacles to be plac ed inside of sherardizing drum, a ng gry about 5 lb. of dust to 100 Ib. 0! terial is used. Before putting # cover on the drum an asbestos ing gasket is put under cover to make drum as nearly air tight as possible The drum is started revolving at about “+ 1 r.p.m. and switch thrown to the high heat wiriné. The high heat is used to bring drum up to des! inet temperature, 350 to 375 deg. C., and give the cor wick- Which the Right th Ww Novembe! 1915 + deposit, and then the low heat is thrown on to * t a temperature for the required period, ie he give the deposit. After this cur- are off and drum allowed to cool to ca leg. C., at Which it is safe to open the drum. The t ess of deposit to give she be ction is 0.0025 in. on a ae ews of 0.005 in. on a diam- sor. This deposit is considered the -ndard and Where threaded parts re to be erardized they must be ondercut or overcut, as the case may be, to allow for this de- posit. In the case of sherard- containing holes and pieces fitting these holes, the allow- ance for sherardizing is made in the ole: in other words, the hole is made 01 in. larger. This increase in de- posit is equivalent to 0.85 to 1.1 oz. per square foot. In every case, ma- terial sherardized as above will stand 170 hr. as a minimum in a salt spray without showing discoloration due to corrosion of the iron, and may endure the spray even very much longer. This is considered the most satisfac- tory and rational test on sherardizing. The salt spray test consists in ex- sherardized articles that ized parts Chart posing the rest on a series of glass rods in a box, into which there is projected by compressed air an atomized spray of a 2!» per cent solution of sodium chloride Care is taken to avoid placing the pieces in the path of the jet. The spray is pro- THE IRON AGE Showing the 1109 tom of the box. The specific gravity of the water is kept at 1.026 and 1.030 at 60 deg. Fahr. The object of the application of these metallic protective coatings is, of course, to enable the coated articles to resist atmospheric exposure with- — FF dk Tt HHH + +—+—+— $4. 4-4 $—F—_+_4-—_+—_ 4-4-4 4 4 4 fg 4 4 4 4 4 o—p—F— 4 4 tt +7 44+ $—4+—4—4—+ 4-4 4 4. 4 tt tt) HH HHH HH Pt 4+—+—-$—4—_4 pp pg Pd dd gd fg dg 40 Find eee ik ok eee ee ee & min a ede dp pet 30> | srr hl Rad teh See Ok ek eee 20 Sees es 10 SF MN LAR2BA KE BIT B*# Hours Run Relations Existingin an Electrically Heated Sherardizing Drum Between Power Input, Time and Temperaturs out rusting for a longer time than they could withstand such exposure without protection. Obvi- ously then, the only final test of the efficiency of a given type of coating is actual exposure to the same sort of influence that the material is supposed to resist in service. If the coating is at Pies Jered toangle press as spacers to keep ~-——~, all efficient this takes so long a time g/ass bars wn position the entire fength of box | : — nimi | Ce that more rapid means of determining _ Veen) angle brass soldered Lj} Sex | relative efficiencies become a necessity. LAL A Beth / oud aieaniii a The most commonly used methods of \ 7? 1 —_—~ test of such metallic protective coat- F = he 10 ie ings are methods of chemical attack, Srasshages a — ig | which in effect measure either the _ | re | 20x e thickness or the weight per square [Aree brass i ae penbece She eee ea ere Astach avhosewpremre wnit of the protective coating. Dis- Lae ol ae er a | cussing the subject the experts of the ‘ier data somssbitaiiel 11 d cha brass tubing General Electric Company hold that [ Watere a |: somnr | Thetuceenters HW oa such methods of chemical attack per- rit | Lay Zome muntare “UM Enlarged view of mit the comparison of results obtained , ' Spray Nozzle from tests upon the same sort of coat- + 24j inva 2 pine i ' ing, but difficulty is encountered when ests cae ae brain foe oon attempt is made to compare the ee ' i tT 7 Hii —_- results obtained by such tests on one meor | Y i} ae sort of coating with those obtained on i Brass hirees BH | 7 Ca eal wap. — |) | aM eee another character of coating. Cover | Cover DER SHPUTERU EER AD In the case of sherardized articles, Hil | ai He 1ai——> it has been suggested that the coat, ia | | ara ferbox which is a combined structure of zinc seviay atitgiummiemme teint’ Cover removed and zine oxide, together with some "ed and all sount’s so/dered zine-iron alloy, be removed in strong ~ — — ——1 alkalies which will not attack the iron | 2s = | [ beneath. This would enable one to de- Maa Spray worth | termine the weight of coating per unit ware. \ Ae 4 = ha) of surface calculated to metallic zinc, es | but the General Electric experience ior Pizpaees = has shown that the results do not ==. Grae Kt necessarily indicate the efficiency of NC ee ae i. ot the coat, and that it is not easy to a eer ae a determine the relative proportions of Spray Box Which the Sherardized Articles Are Tested zine and zinc oxide. ietomneth ikeckh at ' Several years ago, when testing electrical insulation such as is used : of compressed air lifting the water for overhead line construction, it was found that ss ‘ime whence it is projected as a cloud of material which stood fairly well when immersed in ™ chante air. The temperature of the water water failed badly when exposed to the weather, ed by a steam coil placed at the bot- especially if exposed during a hard rain. This led 14 (= cL ® O LZ c ) > 8) 8 s ‘ Wy _— > ~ Gy! 200 ‘ r 59 & 8 £ “ 8 % ~ 2 = 5 a ad m 5 eg ZC = Y 6 “ tt i O © % + q 31/00 8 S 4+ HH 5 . Q S 3| “” s WY | j/ 1 | - | on Pi ff Cc wraiz J ' rison of the Results Obtained by the Salt Spray and Preece Tests to the production of a rain by sending a stream of water through an ordinary rosette such as is used with a gardener’s watering can. The results were encouraging, but too severe, because the individual streams played steadily on one spot and produced erosion. An atomizing nozzle was then tried, pro- jecting a cloud of moisture into a chamber in which the test pieces were exposed. The results were better, but there was still a possibility of some wear if the article was directly in the path of the stream and near the nozzle. The problem seemed to be solved when care was taken in placing the articles to keep them out of the direct path of the jet issuing from the atomizing nozzle. As experi- ence was gained with this type of test, it was found that what seemed to be the essential requirement was the maintaining of an atmosphere substan- tially saturated with moisture, and this saturated atmosphere exposure has been one of the tests regularly applied. The problem of determining the resistance to weather corrosion of protective coatings is, accord- ing to the General Electric attitude, very similar to that of testing insulation for weathering quali- ties. The conditions of exposure are the same, and there seemed to be no essential reason why the saturated atmosphere test would not apply equally well to protective coatings as to insulation. Tests were begun several years ago to try out the method, and the only fault found with it was that it was somewhat slow. Good coatings did not show any signs of breaking down after several weeks of continuous exposure to the fog, yet there was en- couragement in the fact that bare metal began rusting in a few hours, and rust spots began de- veloping on poorly protected surfaces in from a few days to a week. The fact that more trouble is ex- perienced with trolley line suspensions along the seashore than with the same devices inland, led immediately to the trial of an atmosphere saturated with salt water with astonishingly satisfactory results. When exposed as described, articles have a very thin film of moisture over their surface, but there should be very few, if any, drops of sensible size on the objects. Obviously, the test is very searching, as all parts of the surface are exposed, and any pinholes or uncovered areas become evident. This, it is felt, gives an opportunity to learn something of the efficiency of any protecting process in taking care of edges, sharp corners, porous spots in the THE IRON AGE Novembe» 11, 19); metal surface, etc., and by noting the the general final break-down, a very good the evenness of the coating applied may obtained The salt spray test, as it is called, has been ys during the last four or five years, commer the General Electric Company as a ch: products of its process of sherardizi; It was described by J. A. Capp at a meeting June 39 1914, at Atlantic City, of the American Society é», Testing Materials, as reported at some length THE IRON AGE of July 2, 1914. The coated art) cles are exposed to the salt fog, and are examine from time to time to note their service conditioy When the coated material is iron in any of its eral forms red rust begins developing the coat breaks down. The appearance of this req rust may be in small pin points which gradually extend, or it may appear generally over the surface of the article. When the coating is relatively thi and poor, rust may develop in from 2 or 3 to 24 hy. or longer. A better coat will last two or three days but a well applied coat of requisite thickness wil) last at least a week. If no rusting is developed jp this time it is assumed that the life of the coating will be practically indefinite. These figures are based on experience with both sherardizing ; galvanizing. This method of testing sherardized articles \ offered in replacement of the Preece test. Some reasons for this may be seen by referring to one of the accompanying diagrams. As an example, we may take a sample with a deposit of 0.1377 oz. per square foot of surface which has stood three dips in the Preece test and a sample with 0.7 oz. per square foot of surface, or 0.5693 oz. more which stood only seven dips when it should have stood eleven or twelve. ally 1PON the 4 4 Sey. aS SOON as An 8-In. Cylinder Jolt Ramming Machine The Mumford Molding Machine Company, Chicago, Ill., has recently placed on the market an 8-in. cylinder jolt ramming machine of two-piece construc- tion. This form construction is bined with the other features of the con pany’s line of ramming machines, such as full table im- pact and a one-piece steel valve. The ma chine, which has 4 An 8-In. Cylinder Jolt Ramming ‘ 2 in., has Machine of Two-Piece Construc- table 30 x 4 a capacity of 2500 with an air pressure of 80 lb. and is designed particularly for heavy dt) steel foundry work. By employing a pit pattern draft machine it is possible to handle drawbars and knuck'e work. tion The first issue of the C. F. & I. Industrial Bullet to be published quarterly by the Colorado Fuel & Ir" Company, has just appeared. Its purpose, as % pressed in the “industrial representation plan” adop'®* by the directors and employees, is “a means of com munication between the management, the employe and the public concerning the policies and activities : the company; a means of co-ordinating, harmon!" and furthering the social and industrial betterme” work and of informing employees of the personne! proceedings of conferences, boards and committees. is to record social events and industrial developme™™ and diffuse information of material interest. An ope letter from John D. Rockefeller, Jr., in various Ian guages, together with portraits of him and of ord dent Welborn, also Mr. Rockefeller’s address st joint meeting of officers and employees at Pueblo ° Oct. 2, 1915, are features of the issue. (ase-Hardening Retorts and Furnaces* Different Materials Employed for the Former —Precautions to Be Observed in Packing the Boxes — Various Types of Furnaces —— BY R. A. MILLHOLLAND+ Th tter of retorts in which the work is to be bonized is of great importance, more than is the prevalent conception. The pots or boxes, which- aver they might be, should be of a uniform cross- section to insure an even rate of penetration in all F narts of the vessel. White, gray and malleable iron and cast steel are employed extensively for making these boxes, Many users claiming that the steel ¢ onger and hold their shape better under nger and more frequent heats than the boxes of er materials. It is not necessary to go that far afield for carbonizing retorts. MATERIALS USED FOR BOXES The writer uses various diameters of old wrought iron and steel pipe cut into lengths that vill just pass through the furnace door when stand- y on end. One end is plugged with a thin cast- ron disk and the pipe is then heated and the edge rimped over to prevent the disk from dropping out. After the pipe has cooled a %-in. layer of fireclay, mixed to a stiff dough, is tamped down on nside of the pipe forming a gas-tight bottom hat will last as long as the pipe itself. The lids | carbonizing boxes should fit the opening as snugly as possible, allowing for the expansion of heated metal. A whole book can be written on the subject of carbonizing pots, but for ordinary pur- poses the pots made from old pipe will answer as they stand from fifteen to twenty 6-hr. heats with- out wearing out and sealing through the walls. As soon as the pot scales so thin that small holes ap- pear in the walls of the pot, throw the vessel away, for it can not be repaired and the gas leakage is » cause the work to be imperfectly carbon- Old pipe is much cheaper than new castings ind lasts longer. Any junk dealer can furnish you with sound second-hand pipe from 2 to 12 in. in llameter. For gears and round work there is noth- ng to equal the pots made from old pipe. The pots nould be as small as consistent with the size of the parts to be carbonized to secure rapid and thorough ieating at the center of the pot. _ The cast-iron boxes are usually on little feet to allow the heat to circulate on all sides and between ‘he bottom of the pot and the floor of the furnace. ‘he lids should be ribbed on top to prevent warp- ng. This is not necessary in the case of pipe lids ecause they are entirely covered with clay and ‘heir area is not so great as that of the cast-iron ‘es, hence they do not warp so badly as the ex- posed cast-iron lids. The cast pots can be made number of different materials, but experience * Shown that steel castings will withstand a sreater number of heats with less warping than will pots. If the latter are used a very hard ‘ighly desirable. The unannealed iron makes » \celent pot, but care must be taken in handling ~ hew pots or loss from breakage will occur since neaied malleable iron is very brittle. 0m of the materials employed in case hardening HE IRon AGE Nov. 4, 1915, and it is planned to “count of the case-hardening process in a subse- £ metallurgist Millholland Tool Company, In- 1111 Pressed steel pots are used by many large con- cerns that have their own presses and forming machines. One of the illustrations shows a steel pot designed especially for the Stewart gas furnace. As will be noticed a rib running the full length of the boxes on each side allows the operator to handle the boxes while hot with a heavy charging fork. The boxes generally run about 12 in. long by 6 in. deep by 6 in. wide. The reason for the narrowness of the box is to secure rapid penetration of heat to the center, for the more quickly the heat reaches the center of the box the sooner will the parts begin ab- sorbing carbon. If the boxes are much larger than those described the outside rows of parts will begin to absorb carbon long before the ones in the center, and non-uniformity in the depth of carbon pene- tration will be the disastrous result. PACKING THE BOXES In packing the work in the boxes prior to the carbonizing heat, there are a number of minor de- tails to be borne in mind. The work should be free from oil or grease. Often screw machine products are very greasy due to the cutting oil adhering to the parts which can be easily cleaned by immersing them in a boiling hot solution of caustic potash for a few seconds and then washing them off in hot water. The hot water evaporates quickly and leaves the parts perfectly clean and dry. Do not pack the parts in the boxes while they are wet because an excess of moisture is detrimental to the case har- dening and the steam generated is likely to blow out the fireclay seal. Then all the carbonizing gases will escape and the parts will not absorb sufficient carbon to render them serviceable, for carbon like all other forms of energy follows the line of least resistance. It is certainly easier for the carbon to pass out of a large crack in the fireclay that the steam made than it is for it to force its way into steel. Before any parts are put in the boxes, a layer of carbonizer should be placed on the bottom, the thickness being governed by the length of the heat that the box will undergo and also depending on whether new or old boxes are being used. On heats of 6 to 10 hr. a 1-in. layer should cover the bottom and on shorter heats, 4 to *%4 in. is satisfactory. In new boxes the tendency is to absorb carbon, cast iron especially absorbing carbon in large quantities much more rapidly than does steel. When new boxes are being run for the first two times, always increase the layer of carbonizer between the work and the walls of the box by 25 per cent to guard against the decarbonizing effect of the new castings. It is always best to place the articles to be car- bonized in regular rows in the boxes, arranging them in such a manner as to have at least four times the depth of case desired between each piece and being extremely careful not to get too close to the walls of the boxes. Keep the same distance from the walls as the bottom of the boxes. It can not be emphasized teo strongly that the pieces must be kept from touching one another. It is the hap- hazard packing of the parts that is the cause of non- uniformity in both the depth of case and the in- ae nag FP mee eri ee eae Ser) = fe A il , 5 ne eee wv i) SRT PRRs Ps ear nee 1112 tensity of hardness. The thickness of stratum of carbonizer between the layers of pieces should be just one-half the thickness of the bottom layer, but the covering of carbonizer between the work and the lid of the box should be equal to the bottom layer. The sealing or luting of the boxes is of importance, and if improperly spent in packing will not “save the heat” as the fur- nace man would say. In other words if the lids are not sealed on the boxes securely and gas tight, the carbonaceous gases will not penetrate the steel but will escape through the cracks and blowholes in the seal. Fireclay mixed to the consistency of putty is the best luting material yet discovered. Even this cracks away at times, but if the clay shows that tendency mix a little salt or borax with it and it will be found that the tendency to crack and flake off is almost entirely eliminated. A small handful of salt or borax to 10 lb. of fireclay will give the best results. A little trick that the writer has found to be very useful in luting up boxes is to make a long roll of fireclay and lay it around the inside edge of the box just before the lid is laid on, so that when the latter is pressed on firmly and rapped sharply with a wooden mallet the fireclay forms a gasket or packing between the edges of the lid and the sides of the box. Now seal the lid with fireclay and wet the fingers and slick over the seal. Avoid using a trowel; the fingers are much more efficient for this particular operation and are the best for the whole process of luting. After the packed avoid jarring them for the to work loose and leave a gas vent. Now comes the vital part of the whole process of case hardening. In former many men who claimed to know all about case hardening followed this one rule—‘Heat the work as hot as possible without melting it’—regarding the temperature to which the work to be case hardened or carbonized should be subjected. The writer has many times had case-hardened parts brought to him with the query, “What makes these pieces warp so in quench- ing?” prime done, all the care boxes are fireclay is apt day S Nine case out of ten I merely answer one Charging a Case-Hardening Furnace THE IRON with Boxes Having a Special Rib on the Sides to Facilitate the Use of a né Handled Fork AGE November /1, 19} of two things, ““Don’t carbonize at such | or, “if you bring the pieces out of { straight and dip them straight they wo; a badly.” The warping in most cases come . high carbonizing heats. It is not warping a all the true sense of the word; it is the same thing ¢ happens to a Christmas candle when it is left op . hot air register; it sags rather than warp Exae . the same thing occurs with steel under extre, high temperatures. Steel becomes very s peratures above 1800 deg. Fahr. and will s: commodate itself to the supported. Now that the danger line for the carbonizing heat has been drawn it is possible to gain a clearer idea of what is the most practical temperature range for this particular process. Perhaps it may seem foolishly arbitrary to some when it is stated that 1600 to 1650 deg. is the best possible tempers. ture range. Here is the reason why, and it is borne out by exhaustive experiments and by results ob. tained in commercial practice. In the first place, steel with a carbon content of from 0.10 to 0.25 per cent has a critical temperature at which the carbon changes from annealed carbon to the combined state or hardened carbon. It is also an established fact that at this temperature the crystalline structure of the steel apparently disappears and if a piece low-carbon steel is heated to this critical tempera- ture, which is between 1600 to 1650 deg. Fahr. and is quenched in oil, it will show a very fine vel- vety structure when broken. This phenomenon in steel is of great value in case-hardening mild steel for as long as the steel is being heated within its critical temperature range no larger crystals will form in the steel and a soft tough core can readily be obtained when the subsequent operations are performed. If higher temperatures are reached and maintained long enough for the heat to penetrate the carbonizing boxes the size of the crystals in the steel will increase in direct proportion to the crease in temperature. At a temperature below 1600 deg. Fahr., the carbon is absorbed by the steel + of al tem- » and ar. surface on which it il sab 1915 THE IRON AGE of Case-Hardening Furnaces Showing Both be a commercial proposition and, be- the amount of carbon that mild steel will ab- temperatures will seriously impair the hardness of the case. V ssible, the heat control of case harden- ng should be regulated according to a pyrometer, ften the case that no instrument is avail- | the question arises of how can the critical ture be attained and held. The simplest way riter has found is to charge the furnace and g it up to the heat that the eye approximates e within the critical temperature range. When xes have been heated through and through, i small scrap of the same kind of steel that eing carbonized on top of the boxes. Let it me thoroughly saturated with heat, then remove juench in oil as quickly as possible. If, after ng, the piece shows a velvety fracture, then safely assume that the critical tempera- has been satisfactorily attained. It is almost ! le axiom that the critical temperature is t temperature for carbonizing. If the frac- ery crystalline in structure, it is evidence her the critical temperature has not been it it has been exceeded. It takes con- ice to tell which has been the case. rg tals in the fracture generally indicate rneat but if the fracture is identical with an annealed specimen as it comes t is evident that the critical temper- reached. This method is a very crude t good results are being obtained with good way to check up the pyrometer. + E CONSTRUCTION AND FUELS f the proper furnace for case hard- me and it is the candid opinion of some of those sold are worthless, s intention to discuss the virtues or irticular make at this time. One of the Hinge ind Counterba ed 7 the illustrations shows a type of case-hardening furnace heated by gas which is built by the Chicago Flexible Shaft Company. Such a furnace for small work has many advantages over a larger size in that it requires less time to bring to the desired heat, and it is most economical in fuel consumption The Bellevue Furnace Company, Detroit, Mich., and also the American Gas Furnace Company, New York City, manufacture a similar type of furnace, all of which are reliable and serviceable furnaces A whole battery of Stewart illustrated. These are very similar to that shown in the other engraving, save that some have the suspended and counterbalanced door instead of the hinged arrangement. There is very little differ ence in advantage between the two methods of hang ing the doors. The essential principles of all carbonizing fur naces are evenness of temperature throughout the entire heating chamber and reliability in other words, a reliable means of regulating and furnaces are also of cont rol . maintaining the proper carbonizing temperature. There are three distinct types of furnaces for this purpose using different kinds of fuel. The coke- fired furnace in the past has been used extensively for this purpose, but coke as a fuel for heating case- hardening furnaces has been largely displaced by crude oil burning furnaces and by gas furnaces. For practical purposes, the oil burning furnaces have many advantages over the other two types and maintain temperatures sufficiently close for most case-hardening purposes. If natural gas is avail able at less than 35c. per 1000 ft., the gas burning furnaces will be found more economical. The fuel cost will be lower than for oil, and the finer heat control adds materially to its virtues. Besides gas is cleaner and a trifle safer to pipe through a build ing than oil, especially where the pipes cannot he run underground to the furnace. I have known of several cases where a day dreaming pipe fitter took emote” one wonege eoatie eS VOR Ne Re ew peal ey eneepet Fee aA Sexy e aan 1114 a cap from a 60-lb. pressure oil line, thinking it was an air line and a good deal of oil got away before the pumps could be stopped. Gas is really the safest fuel to use, though it is in most in- stances more costly than oil. EXPORT PRICE RECORDS Informing Foreign Sales Office of Changes in Production Costs BY H. A. -—RUSSELL Prices of articles for the domestic trade are usually obtaffied by means of list and discount or net figures. In either event the record is com- plete and easily understood even by those outside of the sales department. Export prices, however, are not. so-easy for the outsider to grasp, and while the outsider is not the one to be suited, yet the price records should be in such shape that a new man stepping into that particular branch of the sales department should have the minimum amount of studying to do. Export prices must include cost of the boxes, cases or other covering; extra labor in- volved in dismantling or separating the various Co, ] PRI ES Form 61-? | at Natl —Aaolahdee ee ee ee Date | DESCRIPTION Disc. | ae Frt. | Ht. Y. Price Date DESCRIPTION Disc | and | Fret | ie | || Packing | | 76 Oomblte Typical Card Used by an Exporter of Agricultural Implements to Record the Prices Charged on Foreign Shipr parts, over and above the amount required for domestic shipment; freight to steamer port, etc. The prices given on the cards shown are made upon the basis of actual cost. The shipments are made on the orders received from our export office. We have nothing further to do after shipment is made from the factory. The first card shows prices on one type of feed cutter, which are fictitious, but will serve to illus- trate our method of recording them. This card shows prices for two sizes of cutters. Usually only one item is recorded on a card. On Oct. 14, 1912, we quoted the export office $16.80 for one No. 6 Eclipse feed cutter boxed, packed and delivered. On Dec. 15, 1912, we received their order No. 4814, which was subsequently filled. These cutters were not exactly what the customer required, and while they were accepted he requested that certain changes be made. Before making these changes we estimated the additional cost and advised the export office under date of April 9, 1913, what the price to them would be for the improved style, also speci- fying it as No. 6A, and further stating that there would be an additional charge of four or five dol- lars for new patterns. On Aug. 14,1913, the export office sent their order No. 5271 for the new style THE IRON AGE Noven cutter at the new price. When shipn on Aug. 24, the additional charge of terns was included in the invoice office. A notation was made at the card for future reference. The other card gives a list of cepair Dart shipped, order number, date and price. Op (ju ; 1913, we completed a price list of all parts for jy new style feed cutter and advised the export offi that the cost to them, including packiny and freight could be ascertained by taking 20 per cent fro, the list price. There is no other card record that the write is familiar with that’ needs to be kept as gey, rately as this one. The index must be well qj divided. The index cards should be of good m. terial, suitable for hard and constant usage, Ty ordinary subdivisions of the alphabet can be use but much better results will be obtained if th cards are printed specially for this record systen, We use celluloid tipped index cards, and they hay paid for themselves several times over, besides keep. ing the wording free from blurs, etc. There is one item of cost which is often over. looked and which pertains more to export ship ments than to domestic, and that is the variow methods of packing the same article for different customers. One will want his shipments packed # that one complete item is in each case. Another will wish to have all the wood parts in one case and the iron parts in another. Again someone else will require five sets of irons in a case and five sets of woods in another case. All these variation will affect the cost and must be noted where nett sary. Usually it is cheaper to pack the irons sé the woods separately; that is, where a number ® sets are included in each case, but even here N. Y. PRICES—REPAIRS AND EXTRAS — . ¢ ir am Reverse of Card Which Is Used for Prices of Rep®* tra Parts 1, 1915 ng may be more than offset by the knocking down the various parts so pack closely in the cases. of export prices must of course be te. Our record of a quotation is made same day the quotation is sent. The recorded in black ink and no further e until a new price has been quoted. ay be necessary for various reasons, lesign, additional equipment which in | be a part of the standard machine, S el of the Seraper Type at Work in the Hok Material from Inaccessible Corners to the Hatch Bucket Can Pick Up a Full Load at Each Gr or a high-priced material in place of what rmerly been supplied, for instance, a vana- teel shaft in place of an ordinary steel excessive advance in the cost of the ma- erials entering into the machine and which were figured on a considerably lower market, or the drop- ff in the size of the specification, as 100 annot be made as cheaply as 1000 or Any of these may necessitate advancing e. On the other hand, increased output, or titution of some other material which may it be equally as good or better for the purpose than the material it takes the may cause a revision of the prices down King up the cards all the various ways ng the machine should be taken into To some parts of the world certain tachments are necessary, while these same parts here would not be used. Therefore, the com- record must include the various combinations. rood policy to destroy the older cards seem to have served their purpose. The known of instances where a customer, t sent in any orders for a number of up the thread again and sends in a equirements. The old card serves then “ing the export office in close touch with the ‘ orders. The dates and order numbers will ‘te the proper correspondence and when wer is sent to the customer it contains the that he requires and not a request nformation. A duplicate set of cards ept in the export office; the records from the same source, namely, the *t r ¥ hich was quoted at San Francisco in >37.50 per flask of 75 lb., is now selling THE IRON AGE 1 Where the He 1115 Power Scraper Shovel for Ore Boats A power scraper shovel intended particularly for the cleaning up of ore and coal in the bottom of boats is being placed on the market by the Brown Hoisting Machinery Company, Cleveland, Ohio. It is designed also for handling material on docks that cannot be reached by dock machines and for han dling various other materials in yards and on the floors of buildings. This machine was developed by S. J. Russell, superintendent of the Buffalo, Roch ester & Pittsburgh Railroad Com pany’s dock at Buffalo, N. Y., and was first used on that dock dur ing the season of 1914. Various improvements were made on an other shovel that was built for the season of 1915 and further im provements have been made as a result of the experience with the two machines. The power scraper shovel con sists of a high power gasoline en gine operating a raisable located at the front of the ma chine. When the shovel is raised as far as it will go, it is turned over in a dumping position and the load discharged. The machine is mounted on two rubber tired driving wheels, and a third wheel at the rear which serves as a trailer and steering wheel. The two driving wheels are connected to the engine by gears and clutches. The hoisting drums for raising the shovel and dumping it are also connected to the engine in the same way. The operations are controlled by levers located in front of the operator’s seat. Brakes are supplied to give better control of the operations The machine is approximately 12 ft. long, 5 ft. wide and 6 ft. high. The width of the shovel is ap proximately 41% ft. In unloading cargoes of ore and coal a certain amount of material that lies between the hatches cannot be reached by the unloading buckets. The shovel is used to place this beneath the hatch open ings, thereby doing away with the hand shovelers The use of the shovel to keep enough material be neath the hatch opening permits the unloading bucket to get a full load at each grab and the time of unloading the boat is reduced. When possible the shovel pushes the material to the desired point, making the handling more rapid than if it were necessary to carry a shovelful at a time. How ever, when working in the bow or stern of the boat or against bulkheads it is necessary to carry the material to the hatch a shovelful at a time. To save time in unloading the shovel is also used for delivering material from two to three hatches to one opening from which the ore is being taken by the grab bucket. The machine can be quickly let down into the bottom of the boat by the ore handling equipment and is quickly taken out when the entire cargo has been removed. The advantages claimed for the shovel are speed and economy. It is said that with its use a boat ean be released from the unloading dock in from | to 5 hr. sooner than when hand shovelers are used and that it saves cost of from two to forty shovelers, depending on the type of boat. The saving in time and labor is indicated by various records that have been made. One of these was in the unloading of the steamer W. J. Mather in 2 hr. less time with two shovels and two laborers, than without the use shovel aia Ginmsiod of an Ore Vesse sting * Se er) ORT ete +e eet es oe en ee ee rere ia Foy et Res» é, ol eee ee : Jip aoe 1116 THE of the power shovels, when thirty-nine laborers were required for shoveling. In taking the ore from the bow of the boat and delivering it to the hatch the shovel has moved 100 tons in 45 min. or approxi- mately in 2 hr. less than was required to do this same work with hand shovelers. SAFETY IN CRANE CHAINS* New Table of Working Loads Needed—Anneal- ing Relatively Unimportant One can readily obtain from most any hand- book a table of so-called safe loads