The Iron Age 1930-07-10: Vol 126 Iss 2

ESTABLISHED 1855 r 3, 1930 NACE VOL. 126, No. 1 Metal Pellets, Produced by Spark Tests, Used to Identify Alloy Steels LTHOUGH the Actes” test for identifying al- loy steels is a very re- cent development, it has already given evi- dence of valuable pos- sibilities as an adjunct to the spark test. As a matter of fact, it is what may be called an outgrowth of the spark test, since it originated from certain effects noted dur- BY WALTER G. HILDORF AND C. H. MCCOLLAM ELLET test is not a substitute for the spark test, but an excellent supplement. Alloy steels readily identifiable by the spark test are not easily distinguished by the pellet test. Conversely, steels whose identification is doubtful by the spark test can be distinguished beyond possibility of error by the pellet test. ing an investigation of physical and chemical aspects of spark phenomena. During the course of the investigation microscopic *Metallurgical engineer and chief chemist respectively Canton, Ohio. This articlé i further elaboration of an article by the same authors in THE IRON AGE, Timken Roller Bearing Co., Oct. 10, 1929. HOTOMICROGRAPHS (30 X) of Pellets: Fig. 1 examinations were made of the cold res- idue, or dust, collected from the spark streams of different alloy steels. It was found that the dust was really made up of two distinct types of particles one, which was in the ma- jority, resembling first cut machine turnings, and the other in the form of small globules, or pellets. Pellets Are Globules Driven Off by Grinding Wheel The former were apparently particles of metal torn off by the action of the grinding wheel, but not af- 1 fected by heat, or chemical reaction. The pellets, how- ever, had quite evidently been heated, at least to the (Left) Represents an S.A. E. 1095 Steel % ith Fig. 2 (Center) an S. A. E. 1015 Steel (0.15% C) and Fig. 3 (Right) an (1% Ch, wit ig ( S. A. E. 1045 Steel (0.45% C) pP' {OTOMICROGRAPHS (30 X) of Pellets: Fig. 4 (Left) Represents in Cr. and Fig. 5 (Right) an since so many of the particles are not subject to any chemical reaction, and therefore are worthless as indicators. For another, which developed later, there was every possibility that the recognizable characteristics of the pellets which had changed chemically would be destroyed, or altered past rec- ognition, by the force of their impact on the glass. Separating Pellets From “Turn- ings” Earliest examination of the cold pellets, however, gave indi- cations of rather remarkable results. But, first, it was found necessary to perfect a_tech- nique for making a detailed ex- amination, since that of the en- tire mass of residue was not particularly satisfactory. The pellets are usually in the distinct minority, and the presence of a large mass of “turnings,” or unoxidized particles, made it difficult to examine them closely. This was soon remedied by the development of a simple, but very effective, method of separation and A large sheet of white paper is held about 30 in. from the grinding wheel, in a plane that segregation. cuts across the spark stream near the end of its tra- As soon as a sufficient quantity of dust has collected on the paper, the latter is shaken to concen- trate the whole mass in a small area. The paper is then tilted, and, since the pellets are rounded, while the “turnings” are very irregular in shape, it is a simple matter to roll the pellets off on to another sheet of paper, leaving the “turnings” behind. This pro- cedure has been refined to secure a more uniform size of pellet by passing the whole collection through a 100 S. A. E. 52.100 Steel (1 Co icee S. A. E. 5145 Steel (0.45 i. be koe n plas ; ( chemical reaction, due with- t doubt to the heatn had taken place. It was as- imeda rom tnelr appearat that these particles ved mportal irt he production of the racteristic spark ] mena. Given tn r? assumption, the next rl i} ther words, if the pres ( ff re! steel affected the spark, l I ils peal ‘ y} son r racteris Bi nd Pit iectorv. nl i a I VV ( held in tne ar} real | 3 ! Pitois, tl nec} ns ( S glass woul ! 1 ld var liff nt alloys Ww! rs e} mvinced ol! iracyv oO n li tion, for seve} reasons. Fo. MICYFOSCO] xan 01 he incrust rom several .d to show any readil Te ne hard] - prising JHOTOMICROGRAPHS (30 X) of Pellets: Fig. 6 (Left) a Steel Containing 1% C. and Shows an S.A. | . 6195 Steel (1° The Iron Age, July 3, 1930 Lz? ale mesh sieve. The sample is then transferred to the hol- low of a= glass microscope slide for examination. Vary Widely in Shape and Color Due to Alloy Content So much for the technique. It was found that the pellets obtained from various alloys vary widely both in shape and in the texture and color of their surfaces. They appar- ently follow a readily identi- fiable form, the characteris- tics for any given pellet being determined by the alloy con- tent of the steel in conjunc- tion with the amount of car- bon present. The uniformity of these characteristics has been thoroughly checked and 1! Va., While Fi Cr. and 0.1 Represents rechecked by countless exami- g. 7 (Right) nations, that have shown no >% Na.) variation in any of them. The 4 alot AR: pC a ce error by means of the pellet test. The table has been pre- pared to show the interlocking character of the two tests. This can probably be brought out most clearly by a consideration of the pellets themselves, with special regard to their characteristic appear- ance. Those selected for dis- cussion come in a group of steels not readily identifiable by the spark test, but accurate- ly segregated by the pellet test. Pellets from a high-carbon steel without other alloys (1095) have been selected as a control specimen, these being shown in Fig. 1. It will be seen that the pellets are quite uniformly round, or at least rounded, the sur- face is smooth, with an al- most polished appearance, and the color is very dark. The color is one of the characteristics of pellets from carbon steel. Chromium Makes Pellets Gray and Round At this point it might be mentioned that the carbon content of plain carbon steels apparently has but little This is brought out in effect on pellet characteristics. peculiar thing about the results was the fact that steels readily identifiable by the spark test are not easily distinguished by the pellet test. steels whose identification by the spark test is doubt- ful at best can be identified beyond any possibility of Conversely, For example, which has no chrome. HOTOMICROGRAPHS (30 X) of Pellet: Fig. 8 (Upper) of an S. A. E. 4195 Steel (1% C., 1% Cr., 0.15% Mo.) PHOTOMICROGRAPHS (30 X) of Pel- lets: Fig. 9 (Left) Represents an S. A. E. 4615 Steel (0.15% C., 1.75% Ni., 0.25% Mo.) with Fig. 10 (Center) an S. A. E. 4615 Steel Carbur- ized and Fig. 11 (Right) an S. A. E. 3312 Steel Carburized (0.15 C., 1.50% Cr., 4% Nii.) cr oes up the shape ol cent they most perfectly round with 1 per cent chrome; at 2.5 guished from steels of the same carbon content that have other alloys present. take a steel with 1 per cent carbon and 1 per cent chrome (52,100) as compared to 1095, An examination of Fig. 4 which shows pellets from such a steel, makes the difference quite evi dent. The pellets are uniform ly round, and smoother, but the greatest distinction is one of color. The chrome imparts a gray, frosted presence of appearance to the surface of the pellets which is found in no other ¢ ase, This distinctive characteris tic of chrome pellets diminishes somewhat as the carbon con- tent goes lower, but it is still present to a degree that enables easy distinction between 5145 and a 1045, as can be seen from a comparison of the pellets in Fig. 5, which are from a 5145 (0.45 per cent carbon, 1 per cent chrome) with those in Fig. 3, which are from a 1045 steel. The same is true in the case of 5120 and 1020. another There is characteristic of chrome that is worth men- tioning. As the percentage the pellets changes; they are al- per cent they start to become irregular and at 4 per are decidedly lumpy in appearance. Vanadium Forms Truncated Shells Figs. 2 and 3, which are pellets from 1015 and 1045 steels respectively. uniform for all three. Comparing them with the pellets in Fig. 1 shows that the characteristics are practically But, on the other hand, these steels fit into the category of those readily identifiable by the spark test, and the pellets are easily distin- carbon and 1.25 per by means of the pellet test. Alloys of the vanadium group are difficult to iden- tify by the spark test, but they are remarkably easy Fig. 6 for example shows pellets obtained from a special steel having 1 per cent cent vanadium. This steel was The Iron Age, July 3, 1930—3 r chosen principally be- cause it gives such a clear idea of what may be called the basic va- Table of Comparative Fields of Spark and Pellet Tests in Sorting Alloy Steels alloys. In the case of the pellet test, condi- tions are reversed. As has been said nadium characteristics. : . , sariier } -¢ discus |] Steels Spark Test Pellet Test earlier in this discus- An examination of 1015 and 1095 Yes No sion the pellet charac- the pellets shows that 4615 and 1095 Yes No teristics become more : ier annie oaks 5 and 4615 Ye N , in every case oxidation, 1019 anc —. . ° and more accentuated : , ze ta 1095 and 52100 Doubrful Yes 7 5 or some other chemical 1045 and 5145 Doubtful T- as the percentage of reaction, has been car- 6195 and 1095 Doubtful Yes carbon content rises. S . 6195 and 52100 Doubtful Yes . ried to a poin ¢ as s 7 ay I t that has 4195 and 6195 Doubtful Yes This may or may not left the pellets mere 4195 and 52100 Doubtful Yes be due to greater heat truncated shells, the resulting from the in- inside being hollow, and the end blown off. The color is jet black, and the surfaces are heavily pitted, with a somewhat polished appearance. Pellets shown in Fig. 7 are interesting as showing that the pellet characteristics of any alloy are never altered beyond recognition by the presence of other alloys with characteristics of their own. This ex- ample is a 6195 steel having 1 per cent carbon, 1 per cent chrome, and 0.15 per cent vanadium. Examina- tion will show that the characteristics of both chrome and vanadium are present. The pellets have the char- acteristic frosted surface of chrome (see Fig. 4) com- bined with the blown out interior which is charac- teristic of vanadium. Alloys of Molybdenum Are Remarkable Molybdenum alloys offer a remarkable example of the interlocking of the spark test and the pellet test. In the lower carbon ranges the characteristic spark of molybdenum is readily recognized by the trained spark tester. In this range the pellets, however, are not readily distinguishable from those of straight car- bon steel. As the carbon approaches 1 per cent, the situation is reversed. The molybdenum spark charac- teristics are obscured but the pellet characteristics be- come easily distinguishable. Fig. 8 is a group of pellets obtained from a 4195 steel, containing 1 per cent carbon, 1 per cent chrome, and 0.15 per cent molybdenum. The characteristic frosted surface of chrome was still present, but the shape of the pellets was entirely different, as can be seen by a comparison with the pellets in Fig. 4. The characteristic of molybdenum seems to be a pellet having a slightly hollow, hemispherical form, the sur- face of the hollow being rough while the outside sur- face is comparatively smooth. Unfortunately this is not too clear in the photomicrograph because the pel- lets tend to rest on the flat surface, but some of them show it quite plainly. This determination has been checked over and over to make sure that the shape is due to molybdenum alone, and the conclusion has been reached that it is. Carburized Steels More Easily Identified One fact remains concerning the pellet test that proves its value as an adjunct to the spark test. Or- dinarily with the latter it is extremely difficult to sort carburized steels accurately because the presence of a high percentage of carbon in the case destroys or ob- scures the characteristic spark phenomena of the other 4—The Iron Age, July 3, 1930 crease in carbon. Be that as it may, pellets from carburized steels show great accentuation of the alloy characteristics, so that identification of carburized steels is actually easier instead of more difficult. Characteristic Shape Found Only in Conjunction With High-Carbon Content This is borne out by the two groups of pellets shown in Figs. 9 and 10 respectively. Both are from a nickel-molybdenum (4615) steel, the former uncar- burized and the latter carburized. As has been said, however, the characteristic shape is only found in cases where there is a comparatively high carbon con- tent in conjunction with the molybdenum. A low-car- bon molybdenum steel pellet will show a structure similar to those from 1020 and 1095 steels. This is apparent in Fig. 9. In Fig. 10 the effect of the excess ‘arbon in the case is perfectly evident; the molybde- num characteristics are greatly emphasized. As a further check on the effect of carburization, Fig. 11 is offered as a comparison with Fig. 10. The former shows pellets taken from a carburized nickel-chro- mium steel, and shows the chrome characteristics very plainly. So much so that there is no chance for error in distinguishing between the nickel-molybdenum and nickel-chromium pellets. Test Has Proved Its Practical Value All this may seem interesting academically, and of a somewhat doubtful value from a practical stand- point. As a matter of fact, the test has already proved its practical value in several instances. It is compara- tively simple to devise a technique for examination that will compare favorably in speed and cheapness with that developed for spark testing. And, further- more a set of standard pellets covering the essential S.A.E. steels can be easily prepared, and preserved for reference purposes, that will add much to the ef- fectiveness of the method generally. Preparation and Use of Standard Pellet Slides Essential In preparing these standards it is suggested that each sample be placed between two glass microscope slides, which are then glued together. The slides can then be indexed and filed in an ordinary slide box. On the whole, considering the ever growing necessity for accurate and reasonably cheap methods of sorting steels, the pellet test seems to have a very definite place in practice. It cannot ever take the place of the spark test, but as a supplement its value seems unquestion- able. a Jj <reeatthon 6b 0h a Sallie ct te eRe A et 2 Saal ins Sn Nate ee aati ER Casting Shake-Out. The conveyor line takes the castings at once to sand-blast department UPPLEMENTING the article on molding and pouring practices at the plant of Eastern Steel Castings, Newark, N. J., which was published in the March 27 issue of THE IRON AGE, the story of handling the castings between pouring and shipping is one of great interest and suggestiveness. Rarely is a period of more than three to four days permit- ted to elapse from the time a casting is poured un- til it passes through the shipping department. This is in contrast with operations under the old methods, so long in vogue in this industry, whereby castings are cleaned in the order in which it is most conve- nient and, correspondingly, some are delayed, through getting to the bottom of the pile, by periods which frequently stretch into weeks. All of this confusion and delay, with the coinci- dent difficulty of keeping customers satisfied and of keeping track of castings and parts of orders, is avoided by the methods now in use. This is part of a general revamping of the entire system, whereby the production of castings has been put upon a man- ufacturing basis under close control. Three transit conveyor lines, with occasional short lines for special purposes, run the length of the cleaning department. These consist of rows of gravity rollers made of seamless steel tubing mounted in ball bearings, sealed against entrance of abrasive matter. They are operated so easily that a man can shove several tons of weight along such a conveyor with little effort. A complete system of weighing and checking of "*President, Eastern Corporation, Graybar Building, New York; formerly vice-president and general manager, Eastern Steel Castings, Newark, N. J Straight-Line Cleaning of Castings BY E. F. MILTENBERGER* weights pervades the entire plant, from the time the casting leaves the shake-out grating until it is shipped to the customer. Sprues and risers going to the open-hearth furnace are weighed at point of cutoff. Castings are weighed box by box before grinding and afterward, as the grinding labor is compensated in large part on the basis of the amount of metal removed. This checking of weights all along the line follows a carefully thought-out and pre-determined schedule, whereby the management knows every day just what the previous day’s opera- tions have been in production, parts in process, un filled orders, partly filled orders, etc. Shake-Out Is Starting Point Cleaning properly begins on the shake-out. The inclined, shaking grating on which sand and cast- ings are dropped brings the castings down within reach of a man with a hook. He hooks them off into boxes on skids running on the roller conveyor sys- tem. As soon as a box is full it passes immediately to the first cleaning operation, which consists in getting rid of the gates and risers. Depending upon the size, these are burned off with an acetylene torch or cut off in a sprue-cutting machine. Minus their major appendixes, the castings then pass on to the general cleaning division, which in- cludes sand blast, grinders, chippers, tumbling bar- rels, welders, etc. All castings are inspected before they reach the sand-blast unit. A goodly percentage of all discards goes out at this point, as the inspec- tors’ bonus begins only after 75 per cent of all the day’s defectives are discarded here. The Iron Age, July 3, 1930—S5 Castings small enough so that the sprues and risers may be handled in a sprue-cutting machine go to that unit, the heads and gates being thrown into an open-hearth charging box on an ad- ng line of roller conveyor. The castings them- selves are then thrown upon the loading table for I ! ast barrel Larger castings go to the Ss irntable for blasting at once Thence cross an inspector’s table, from which they art ished off into a box passing underneath ivevors hese larger castings are weighed as they enter ! rn-off department. Sprues and risers burned ’ fi into open-hearth charging boxes, which eighed. The irner operator throws the astings into boxes on what are known as classifying nveyors, consisting of two lines of roller convey- s, Which may accommodate a dozen or more boxes ne tin Leaving this department, these castings | ire weighed out and the ght thus obtained is that ’ y S nos g ; ! ; ; ' : i Passing Through Cleaning Operations Li From the three main transit lines boxes of cast- ngs are switched off on to transverse side tracks for he grinding operations necessary. The smaller cast- ngs go at once to a row of stand grinders, where the yperator works from a full box into an empty box. Each box, when filled With ground castings, shoved back upon. thé WING Grinders in the Cleaning Department Taking Care of Medium-Weight Castings. Note the suspension, permitting adjustment of the the swing grinders, which are grouped in pairs. Each stand or pedestal has two grinders, one at either side, and it is fed from both sides. Ground castings from the swing grinders follow the same procedure as the smaller castings, in getting back on the main transit line after the grinder is through with them. Both sets of castings are weighed again after grind- ing, as the grinders’ pay is based upon the amount of metal ground off. Several types of grinders are in use, the stand grinders, usually with two high-speed wheels, em- ploying two men. The innovation in the swing grind- ers lies in the two direct driven units on each stand or pedestal and in the way each grinder is balanced. These grinders are located between the main lines of conveyors running through the department, there being one row of grinders between the first and sec- ond lines of conveyors and another row between the second and third lines. Each stand is served by a short transverse sec- tion of rollers holding one or more boxes. Castings are commonly taken from one box, passed through the grinding operation, and returned to a second box which, when filled, is sent out along the main line. Chippers work in groups of two, each on his own table, with an inspector between the two tables. The table is a sort of double bench of concrete, with a top surface of wooden paving blocks. Each cast- ing, as the chipper fin- ishes with it, is shoved across the table toward balance and of the height of the wheel 6—The Iron Age, July 3. 1930 RIMARY Repairs (Above)—Electric or Gas Welding, with Swing and Stand Grinding and Chip- ping—Are Available Prior to Annealing. Here the fifth inspection takes place (man in right foreground). Unloading Tumbling Mills, by Crane When Necessary, to Classification Benches and Sixth Inspection (Below). Man in foreground is weighing out finished castings The Iron Age, July 3, 1930-—7 = the inspector (incidentally, this is the fourth in- spection in the cleaning department). Thence, from the bench the castings are classified into waiting boxes on a cross-line of conveyor. This classifica- tion involves three groups of boxes—one for cast- ings going to the annealer, one for those going for minor repairs to the electric welder and one for the acetylene welder. Repairing Castings En Route After welding has been done upon such castings as need it, they pass through stand and swing grind- ers and chippers in the repair department. Follow- ing a fifth inspection, the castings are sent into the annealing line. In all of this work there is no back- tracking. The progress is definitely toward a speci- fied point and each casting takes its course along the stipulated lines of travel. After annealing, the castings are rumbled. Large castings are placed in the rumbling barrels by means of a crane, while small ones, handled in boxes, are passed into the barrels from the boxes. Another classifying, included with the sixth inspection, de- termines whether any castings require further re- pair. In cases where this is necessary they are sent to the secondary repair department, which is a com- plete unit in itself. Following this the castings get back again into the main line toward the shipping floor, along with those castings on which no secon- dary repair was found necessary. Repairing of castings, a well-developed feature in the making of steel castings, is done largely by either electric or acetylene welding. ‘There are several pieces of equipment adapted to these processes and located conveniently with regard to the cleaning conveyor lines. Boxes of castings requiring this treatment are taken off the main lines as they pass, 8—The Iron Age, July 3, 1930 directly into boxes which reach him on the line running under his table. They proceed toward the left and are on their route to the shipping department. After undergoing such repairs as are necessary they pro- ceed immediately on their way. A secondary repair unit, in a wing of the main building, takes care of any repairs required after an- nealing. This department is equipped with all the necessary devices for carrying on a complete repair, including grinders, chippers, welders, etc. By handling castings thus virtually in the order of their production, the previous trouble, from their piling up and certain castings being hidden at the bottom of the pile, is obviated. It is, of course, per- fectly feasible, on a rush order, to push through a box of castings out of its regular turn. The produc- tion methods in vogue, however, are so adjusted in sveed that customarily no such treatment is needed. AND-BLAST Department, with Turntable and Car Rooms. Inspector at left of turntable puts castings weighed in to the burners Inspection of the castings begins, as already noted, before the gates and risers have been re- moved. The inspection is repeated after each suc- cessive major operation until they are ready for shipment. The great run of items comprising the product have six inspections, at any one of which the casting may be thrown aside for repair or re- jection. Efforts are made to avoid doing work on a defective casting. The sooner its defect is discov- ered, the less is the expense involved. Hence, these inspections are rigid and searching. Skids Help in Assorting for Shipment Use is made in the shipping department of a large number of sheet steel trays or skids. These are set on blocks in such manner that the nose of a lift truck may be run under for picking them up. They constitute not only handling units, but what is per- haps more important at this point, sorting or as- sembling units, whereby pieces of the same pattern or going to the same cestination may be brought to- a eer. vr ete ala i al Ag PE ee ot gether and an order thus completed. This department is served by a railroad spur and also by facilities for handling motor truck shipments, which constitute the greater portion of the outgoing tonnage, as the busi- ness is largely localized. Overhead crane service is available here, both for heavy castings and for handling skid loads of smaller castings. Nowhere along this line, from the shake-out to the shipping room, is there an accumulation of work. The equipment now installed is adequate to care for present needs as fast as the tonnage is provided. There is room for expansion in the cleaning ‘ ECONDARY Re- \J pair Department Is a Complete Unit in Itself department, amounting to duplication of its capacity, by means of an added group of three more lines of OURTH Inspection Occurs at the Chipping Department. Ground cast- ings are shown being weighed in, at two points. The inspector (A) takes care of chippers on two benches, between which he stands main conveyors in the adjoining bay. As was made clear in the first section of this article, the work is almost wholly jobbing. Few orders call for more than 50 castings from a single pattern, and the va- riety changes daily. The Iron Age, July 3, 1930—9 A Machine Tool Builder’s Experi the e xX- perience of William Sel- Jers & Co., Inc., indicates that in metal cutting, tungsten - Car- bide tools have EE OE AE great possibil- CUTTING TOOL RECORD WM. SELLERS & CO., INC. TO BE FILLED IN BY FOREMAN OR RATE SETTER a Cutting Tool Name or Symbol en Machine on which Tool is used Cutting Speeds Feeds Depth of Cut Condition of Tool After Cut BO RD OE Be citi Cubic Inches of Metal Removed No. of Pcs. rial should be used. He inves- tigated failures, which if due to the set-up or to the machine operator, he cor- rected accord- ingly. If the fault lay else- where, he ities. But there Order No._ Pc. No. are many limita- Name of Piece ; : tions and these Remarhs } must be _ thor- 3 1 TO BE FILLED IN BY OFFICE | oughly under- eee stood if the ma- , . Size of Shank terial is to be used successful- iy: | Sn abies. Fig. 1—Records Are Kept oo Job Using Tungsten-Carbide hicilc: diliee wiih: ools there are de fects and inher- ent weaknesses still to be overcome by the producers of this material. The Sellers shop does not engage in quantity man- ufacture. Except for two or three small machines which are produced in lots of 25, most of the work is in quantities of 2 to 12, the larger pieces—up to 40 tons in weight—being built singly or in pairs. Machine operations are paid for on a piece-work basis, so that in applying the new tools to the various opera- tions the rate setter has had to work with the machine operators. When the first tungsten-carbide tools were purchased and placed in the shop a member of the supervisory force was assigned part time to follow them up. He worked with the manufacturer’s appli- cations men in recommending jobs on which the mate- FIG. 3 FIG. 4 IG. 3 worked with the manufac- turer’s repre- sentative to cor- El € itat e $$ —— ________. Size of Tip and Method of Holding rect it. Tungs- ten-carbide ried in the tool- room, from which any operator can draw them upon proper authorization in writing from his foreman. The foremen are sufficiently familiar with these tools to know where their use is desirable. New applica- tions are followed up by the tungsten-carbide expert and if adopted, the rate department adjusts the piece- work price accordingly. For certain jobs the stand- ard operation sheets specify use of tungsten-carbide tools. Before a machine operator starts to use these tools he is given written instructions in blueprint form. While the tools are in the experimental or de- velopment stage, a “Cutting Tool Record,” Fig. 1, covering each job, is filled out by the foreman or rate setter and forwarded to the engineering depart- FIG. 5 Typical General-Purpose Tool. The tip is so set into the shank that it is supported firmly on the bottom and - backed up on one side and the rear. This tool, perhaps the most commonly used, is successful in moderate cuts. Fig. 4—Bridge tool for heavy roughing. Holds the tungsten-carbide tip securely but the projection or bridge on top makes grinding difficult and interferes seriously with the chips on heavy cuts. Fig. 5—Dovetail tool for heavy roughing. 10—The Iron Age, July 3, 1930 be a ment through the superin- tendent. Each tool is given a serial number, and by means of report cards de- scribing the tool, date of purchase, etc., a _ close check is kept on its per- formance and its profit- ableness. Those that are not proving economical are immediately investigated. Proper grinding of the cutting edge has _ been found very important to the success of these tools. A keen edge (one that does not show irregularities even under a magnifying glass) is essential for all but the heaviest roughing operations; even for the latter a much sharper tool is desirable than when using high-speed steel. Clearance angles should be somewhat less than those adopted as good practice for high-speed steel because the inherent ence with Tungsten-Carbide Tools HEN first introduced at the plant of William Sellers & Co., Inc., Philadelphia, about two years ago, tungsten-carbide cutting tools, because of application difficulties, were opposed by many of the machine tool oper- ators, Today, these operators complain if such tools are not available when wanted. Application of these tools in the Sellers shops has been confined for the most part to machining cast iron. They are used on engine lathes, turret lathes, boring and turning mills of all sizes, horizontal boring machines, and on planers, both large and small. All such tools are machine ground by one “experienced” man and are issued from the toolroom as other tools. Performance records are kept, and where found profitable tungsten-carbide tools are specified on the standard operation sheets. Thus for many operations use of these tools has become part of the regular shop routine. Experiences with this new tool material are outlined in this article, which is abstracted from a paper presented by Coleman Sellers, 3rd, ex- ecutive engineer of the Sellers company, at the semi-annual meeting of the American Society of Mechanical Engineers in Detroit,, June 9-12. company. Furthermore, the machine operator is not permitted to grind his own tools, because under such conditions it would be im- possible to control the quality of the grinding or assure use of the correct rake and clearance angles. All dull tools are returned to the toolroom, where they are ground by an experi- enced operator. Hand grinding not only tends to produce mediocre results, but it is slow and expensive, said Mr. Sellers. Tests are said to have shown that grinding by hand takes three to four times longer than by ma- chine, to produce an equal- ly good cutting edge. This is partly accounted for by the fact that with hand grinding it is necessary to rough on a 60-grit wheel and finish on a 100 or 120-grit wheel, whereas with lack of strength of tungsten-carbide necessitates the machine it is necessary to employ only one wheel supporting the cutting edge of the tool as rigidly of 60 or 80-grit. as possible. With some types of brazed tools, espe- cially those subjected to heavy cutting pressures, it is desirable to grind a slight negative back slope on the top of the tool. This tends to hold the tips in Machine Grinding Permits Use of Water Another advantage of machine grinding is that it permits the use of water, which speeds up the place, and offsets the tendency to pull away from the operation. Hand grinding cannot be done wet with shank. Hand grinding has been eliminated entirely by the FIG. 6 Considered the most satisfactory of all because the tip is accessible Fig. 6—Tool for general work. This holds the tungsten-car the depth of cut is too limited and only light cuts may be taken. very satisfactory any degree of satisfaction, because the quantity of b ee ee a hie Ser a FIG. 7 for any required depth of cut and for grinding. bide tip satisfactorily, but unless the shank is ground away Fig. 7—Finishing tools of this type have proved water required would obscure the tool from the eyes of the operator, besides ne- cessitating continual wet- ting of his hands, producing unpleasant and in_ cold The Iron Age, July 3, 1930—I11 weather almost impossible working conditions. A little water is worse than none, because it tends to injure the tungsten-carbide by alternate heating and cool- ing. If water is used it should be in abundant quan- tity, at low velocity and directed to the part of the tool in contact with the wheel. A further advantage is elimination of the abrasive dust, which in heavy cutting is serious because of the excessive wear of the soft wheels required to grind tungsten-carbide. iy | Ferns roe 4 fis 8—Bed of Plate Trimmer Machined on a 120 x 120-In. Planer With ? > 1 a 2 x 2% x 14-In. Tung- sten-Carbide Tool. The top surface was roughed at 40 feet per min., 3/16-in. feed, -in. average depth of cut The scale on this casting was bad, and the cut was intermittent The grinding machines used in the company’s pre- iminary tests, and later in regular practice, were two Sellers tool grinders, one of them for tools over 1™% x 2-in. in section. Time of grinding varies from 35 min., for shaping out a very rough tip placed on a 142 x 2-in. shank, to 3 min., for touching up two sur- faces of a tool. A variety of tool shapes are used. Manufacturers’ recommendations have been found satisfactory, al- though not necessarily the most efficient. A grinding chart prepared as instructions for operating the smaller Sellers tool grinder is shown in Fig. 2. The offset tools shown in Figs. 9 and 10 of this chart are good all around roughing tools, the curved cutting edge having an advantage for tungsten-carbide, inas- much as the curved edge eliminates some of the shock 12—The Iron Age, July 3, 1930 which takes place on entering or leaving the cut. In connection with this grinding chart, Mr. Sel- lers pointed out that in grinding the tools only slight pressure should be applied. A good operator, he said, soon gets the “feel” and will not attempt to hog off the tungsten-carbide. Under no conditions when grinding dry should a tool when heated from grind- ing be dipped into water. Lapping after grinding will produce a keener cut- ting edge; but in machining cast iron no advantage has been found in this extra operation. After cutting a very short time a lapped tool has no better edge, even in finishing cuts, than a carefully ground tool that has not been lapped. Too much emphasis cannot be put on the necessity for rigid holding of both the tool and the work. The shank must be of sufficient size for the pressure exerted in cutting and the tool must be supported as close to the cutting edge as_ possible. The machine tool should not have any lost motion in the tool- post or tool-apron, and the work must not spring. If these con- ditions do not obtain, chatter, the worst enemy of tungsten- carbide, will result. Regarding intermittent cuts, thought by some to be imprac- tical, Mr. Sellers pointed out that operations involving such cuts are being done at the Sel- lers plant every day. One ex- ample is the planing of plate planer beds, Fig. 8. There is no particular difficulty in using these tools on planers, but tool lifters should be employed so that the tool will not drag over the work on the return cut, with the danger of loosening the tip. Various forms of the tung- sten-carbide tipped tools are used by the company; some of them are shown in Figs. 3, 4, 5, 6 and 7. All tools are brazed to the shank, but some are also held by other means, brazing by itself not always being sufficient to resist high pressure. Failures of tungsten-carbide, as experienced by the Sellers company, are said to be roughly charge- able to tip loosening, to soft tungsten-carbide, and to tip breaking or chipping. Loosening of the tip seems to have been caused by improper brazing, which appears to have been corrected largely by the manufacturers of the tools; and also by improper backing. In this, the shanks did not have sufficient metal at the sides of the tip to prevent slight movement sideways, loosening the tip. The remedy is heavier shanks. Tips are broken or chipped by having too light a shank; this allows the shank to bend and thus re- » tn ee wn ty OLD, Nig ae races + iw SAME ts Pin ates bilan tA onc a Dade sn ens ah entice ais accans alicia at Rl vend te’ D suited stomachs 2 3 Pins oie 1 aioe moves the support from under the tip and causes it to crack. The tools chip and break also because of too much copper in the braze; the remedy lies in secur- ing closer contact between tips and shank, allowing only 0.001 in. or 0.002 in. for the copper. Tips are broken or chipped by too great a clearance, which does not give proper support to the cutting edge. Chatter caused by loose bearings on the machine tool, by shanks too light for the cut, by improper support for the tool, in- correct feeds and speeds or by incorrect tool an- gles is also a cause of tip cracking or chip- ping. If the chatter is of low frequency, it does not do much harm, but if of high frequency, it is usually disastrous to the tool. Another cause of tip breaking or chipping is in not relieving the feed when breaking through the end of the cut. This applies to bor- ing and turning where the cut is heavy and the material is hard. The feed should be lightened as the tool is about to run out of the cut; otherwise when the tool first breaks through, the spring in the shank will be relieved and the ef- fect will be to increase the feed suddenly, tend- ing to cause excessive pressure and tip break- age. Heavy feeds on in- termittent cuts is an- other cause of tool breakage. For instance, a square piece of work on a boring mill should not be roughed with a heavy feed until the cut becomes continuous. The gap between the cuts will allow the feed to accumu- late and cause too great a shock when the tool strikes. Pig i. Pig 2. Fig 3. Fig 4. aames point tet teste Tools forming atlachment. Cent Coan RB LA Offeet Tool shown on Fig 14. Jus Pig 18. SE front clearance angle B side * C+ top side slope D- top back slope . SELLERS & CO., Ine., Increased Speed the Chief Advantage Outstanding applications of the tungsten-carbide tools at the Sellers plant include the planing of large ring gear segments on a 72 x 72-in. planer; planing 10-ft. boring mill uprights on a 72 x 72-in. planer; and planing the bed of a floor boring machine on a 60 x 60-in. machine. Also, boring long half-bearings bolted together on a 5-in. horizontal boring machine and rough and finish turning and facing the table of a boring mill. Mr. Sellers concluded with a summary of the ad- vantages and disadvantages of tungsten-carbide tools GRINDING CHART TUNGSTEN CARBIDE ‘TOOLS Ooo SF Ae otreet toe ls serine uae STRALGNT FACE TOOLS All straight face tools, such os avove, should be md with the tool held in (he rectaenguler tool helder or chuck. Rounde ormers of less thas 1/4” radius can de ground without rosetting the tool ont without using the To prind smell redii crind 1 flat 48° and 2 small flats at 22h° and 67° 38 siown on Fit 12. Whon radius exceeds 1/4", or curve must be oxactly smooth the forming attachment or the corroct cam must bo used. J 9. \ 10. f il. Round Kose CURVED PACE TOOLS All curved face tools, such as shovm in jigs 9 to 11 should be ground by means of the forming attachment with a suitable cam to develop the correct shape. Your machine is furnished with one cam for a right hand offset tool, as shown on Fig 9, and ono for left hand offset tool as shown on Fig 10. Cams for additional shapes may be furnished by us, ot an extra price, orwe will supply upon order cam blanks from which you can muke your own cams. For grinding offset tools pluce tool shank against side of rectangular The cutting edge should beas close to the com as possible and. the cutting end should be even with the cae. Careful setting of the tool will avoid wasteful grinding of the tungsten carbide tip. Whon grinding round nose tools the cas is not required as the shape of the holder is such thet it may be usod without any cas, placing the tool in the middle of the rectangular hole with gutting edge close to the cam as hole in holder as shown in Fig 15. Cast Tools above } . Ma. Tools below if Philedelp Fig. 2—Instruction Chart Prepared for Use in Machine Grinding Tungsten-Carbide Tools as experienced so far by his company. These apply to cast iron, and may or may not apply to other ma- terials, he said. Increase in speed with the same feed and depths of cut, thereby removing more metal in a given time, was cited as the foremost advantage. Sand and scale, which cannot be cut by high- speed steel, usually can be cut without harmful effect. Scale up to a hardness of 700 Brinell has been cut with the tungsten-carbide _ tools, but above that hardness the cutting edge becomes damaged and the tool breaks down. Hard cast- ings which through some slip in the cupola charge or for other rea- sons turn out too hard for the usual cutting materials may be ma- chined with tungsten- carbide tools and thus saved from a return trip to the foundry, for annealing, or from the scrap pile. In long finishing cuts an advantage of tung- sten-carbide is that the tool maintains its size throughout the entire operation. Much time is lost when there is even slight wear on a tool in the middle of such a cut, necessitating changing the tool and _ possibly starting the cut over again. The high cost of the tools and the increased cost of grinding were cited as the foremost disadvantages of the new tools. The lack of strength of tungsten- carbide necessitates handling the tools with care; if the tools are dropped on a hard floor or knocked against a casting there is danger of chipping or cracking the tip. In some cases no advantage results, and use of tungsten-carbide tools is a needless expense, said Mr. Sellers, referring particularly to cuts which are al- ready at the limit of power of the machine tool. Unfortunately, many shops have machine tools which were built before production had reached its present great height, he said, and such equipment prevents its owners from making full use of this remarkable material. “Tungsten-carbide is still in the development stage,” Mr. Sellers continued. “Judging from the progress a7. (Concluded on page 60) The Iron Age, July 3, 1930—13 The “Grave Yard” of Old Cars at the Rouge Plant of the Ford Motor Co. at Dearborn. The cars, representing vari- ous makes, many of them obsolete, are awaiting their turn on the salvage line Ford Scraps 375 Automobiles Each 16 Hr.; Even the Grease Saved ITH the automobile industry as a whole searching for the best method of solving the problem of the old car and ridding the high- ways of discarded hulks, the Ford Motor Co. has con- ducted during the past few months an interesting ex- periment in scrapping automobiles, which the com- pany announces has been found so practical that plans are being made for increasing salvaging facilities and continuing the work on a more extensive scale. Under the auspices of the National Automobile Chamber of Commerce, other automobile manufac- turers recently put forth a plan called the National Safety Highway Campaign for the purpose of meeting public complaints regarding the disfiguring of the landscape by abandoned cars. The Ford plan, it appears, not only brings in the old cars that otherwise might be left by the roadside, but turns the old material that is recovered to useful purposes. A force of 120 workmen is now employed at the Ford Motor Co.’s Rouge plant at Dearborn, Mich., dis- mantling old cars at the rate of 375 every 16 hr. It has wrecked 18,000 old automobiles by a disassembly method patterned after its famous assembly line for automobile production. At Buffalo the Ford company is about to erect a new reclamation plant, where similar automobile scrapping methods will be employed, and presumably 14—The Iron Age, July 3, 1930 the old material will be sold to steel mills and other scrap consumers in that district or shipped by boat to the blast furnaces and open-hearth furnaces of the Ford plant in the Detroit district. In its dismantling process the Ford company sal- vages many parts, such as tires, in their entirety. Some other materials are being converted into useful articles, while the iron and steel is remelted in the furnaces to do its bit in the manufacture of Ford cars and trucks. Pays $20 for Old Cars The derelicts are bought from Ford dealers at a fixed price of $20 acar. There is no restriction as to make, age or condition, except that all cars must have at least some semblance of tires and a battery. Commenting on its plan, the Ford company says that “the salvaging of cars that have outlived their usefulness serves three ends. It will rid the high- ways of motor menaces that are dangerous both to life and traffic, it will to a large extent free the land- scape from unsightly junk piles, and it will convert into usefulness material that would otherwise go to waste.” Experiments were begun by Ford engineers on Feb. 5. Three moving conveyors are now in oper- ation in the open-hearth building. Two are used for dismantling purposes, one for Ford cars and one for cars of other make. The third carries scrap iron and Wa de 4 POE Le RO ne aI Aina - nti ow steel to one of the 10 open-hearth furnaces, and other salvaged material, such as batteries, tires and floor boards, to waiting trucks. Gasoline, Oil and Grease Saved The present method of scrapping is first to drain the cars of gasoline and oil, both of which are sal- vaged. Grease is also saved. The cars are then hauled into the open-hearth building and placed on a progressive conveyor. The headlight lenses and lamp bulbs are recovered, the spark plugs and battery ar taken out and all glass is removed. Glass which is whole or may be cut to useful sizes is utilized for glaz ing in Ford plant buildings. The broken bits are sent to the Rouge glass factory for remelting. Floor boards travel to the box factory to be used for crate tops. The cotton and hair obtained from upholstery and roof are separated, baled and sold. The muslin from car tops and the better grades of upholstery covers are made into buffer and polishing wheels. The imi tation leather got from curtains and tops is immedi- ately transferred to electric sewing machine operators near the conveyor line, to be transformed into aprons for use in the blacksmith and other shops Smaller pieces and trimmings are fashioned into hand pads All Parts Segregated and Saved Gasoline tanks are pressed and baled for the reco, ery of terne plate. Overhead compressed air wrenches FTSHE Old Cars Move Slowly Along on a Conveyor While Work- men Remove Tires, Glass, Roof Material, Spark Plugs and Other Parts that have been set in reverse unscrew the wheel nuts. When the wheels are removed the tires are inspected. If the tread is good they are sold as used tires at the commissary. Otherwise the entire unit is placed in automatic shears which sever both tire and rim. The tire is quickly stripped and tossed into a waiting cart to be sold as old rubber. The rims join others for use as Turnace scrap. Horns are salvaged. Likewise hubcaps for alumi- num, ignition wire for copper, oil cups for brass, bushings for bronze and other bearings for babbitt. All metals are kept separated by depositing each kind in steel barrels. As the conveyor-propelled and now all but dis- mantled cars reach a station near the end of the sal- vage line, men with oxygen torches burn the motors loose from the frames. Overhead compressed air hoists are attached to the motors and they are swung toa washer. This bath of boiling water and soda ash expels them from the opposite end free from grease and dirt. Meanwhile, what is left of the cars con- tinues on the conveyor into a 22-ton press, which crushes them as one would demolish so many match boxes. The remains are then transferred to the third onveyor, which carries them to the furnace doors. (Concluded on page 60) HAT Is Left of the Car Is Crushed in a Press So That it Can Be Shoved into a Furnace for Remelting of the Steel. The picture shows a car that has just come out of the press and that is about to be transferred to another conveyor which will carry it to the furnace The Iron Age, July 3, 1930—15 TEEL in its various aspects again was the sub- ject of much discussion at last week’s meet- ing of the American Society for Testing Ma- terials in Atlantic City, N. J. And, as befits a progres- sive group, the conferences centered upon applications of present-day importance, such as aircraft, big bridges, ships, pipe lines and heat and corrosion re- sistant equipment.