q e HIGH SPEED TOOL STEELS
BY
HENRY BERNHARD DIRKS, B. S„ 1904
THESIS
FOR THE DEGREE OF MECHANICAL ENGINEER
IN THE GRADUATE SCHOOL
OF THE UNIVERSITY OF ILLINOIS
PRESENTED JUNE, 1905 UNIVERSITY OF ILLINOIS
May..36,..1905... 190
T HIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY
HENRY BERNARD DIRKS
ENTITLED HIGH SPEED TOOL STEELS: INVESTIGAT.IOHS... AND..TESTS.
IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE
of Me clianlc a .1 Engineer
HEAD OF DEPARTMENT OF Mecliaiiicfil Engineering TABLE OF COHTEHTS
HIGH SPEED TOOL STEELS Page I. Development of Tool Steel Industry. 1.
II. Manufacture of High Speed Tool Steel
( a) Selection of Materials 3.
(b) M eltin g 4.
( c ) Annealing 5.
(d ) C ru cib les 5.
I l l . E ffe c t o f various Chemical Constituents 6.
(a) Carbon 7.
(c ) Tungsten 8.
(d) Molybdenum 8.
(e ) Tungsten with Molybdenum 8.
( f ) S ilic o n 9.
IV. Tempering 9.
V. List of Firms Selling High Speed Steel 15.
VI. Experimental Data of Tests mad.e to Date 16.
VII. University of Illinois Experiments 32.
( a ) The Tool Steels Used 32.
(h ) The C a st-iron Test P ieces 36.
(c ) Details of Tests 41.
(a) Results of the Tests 51.
(e ) C onclusion 52.
Bibliography 54. - 1 - HIGH SPEED TOOL STEEL. | I -DEVELOPMENT OP TOOL STEEL INDUSTRY. The manufacture of crucible tool steel probably dates back thousands of years as is evidenced by the wonderful carv ings on intensely hard stone work of the ancients. The fir s t tool steel of which much is known is "Wootz" steel, which was produced in India centuries ago. This steel was made by melt ing small pieces of wrought iron, together with pieces of wood and green leaves, in a crucible made of earth and charcoal. This steel was for some time imported by English companies and used for making tools, and although this is no longer the case, it is still carried on in some districts of India. The celebrated Damascus steel, produced at the forges of Toledo was also a crucible steel, and it is recorded that this steel contained certain precentages of tungsten, nickel, man ganese, e tc ., some of the very elements contained in our pre sent high speed steel. It seems remarkable, therefore, that a latent high speed steel which may be said to have existed centuries ago, was not discovered before the present day, when a ll that would have been necessary to bring out its inherent powers would have been the heating of it to such a high degree o f temperature as was formerly thought to destroy the to o l. It was in Sheffield, England, that crucible steel was first extensively manufactured, by Benjamin Huntsman, during the year 1750; and it is to him that the world is indebted for one of its greatest industries. Huntsman was originally a watchmaker by trade, and it is said the d iffic u ltie s he had -2- with his springs led him to turn his attention to the produc tion of his own steel for them. Prom this time on, it was not until some thirty or forty year8 ago that any marked advance was made. This was the in troduction of Mushet, or self-hardening steel, which was the valuable invention of Robert Mushet, who, after a series of experiments, made while he was manager of the Titanic Steel Co., England, succeeded in producing a tungsten steel, and its introduction was a great advancement on the cutting powers of ordinary crucible carbon steel. It is to America, however, that a ll honor must be given for the next great step in having led the way in the present remarkable advancement in tool steel. Credit for this advance is due mainly to Messrs. Taylor and White of the Bethlehem Steel Works, who during the years 1898 to 1900 made extensive experiments on this subject, and that their persistent effort proved a success was fir s t demonstrated at the Paris Exhibi tion of 1900, where the Bethlehem Steel Works exhibited by actual tests the capacity of their Taylor-White tools. These experiments of Taylor and White came as a result of a rush of orders with the Bethlehem Steel Works, who seeing that at the rate they were working the orders would never he completed in contract time, resorted to this method of increasing the out put of their machine shops, the building of extensions and new machine tools being out of the question in the short time be fore the expiration of the contracts. Thus we have the high speed or rapid cutting tool steels -3 - or as Mr. Reiser rightly called them "superheated steels", they "being heated to a temperature which in ordinary carbon steels, would have destroyed its cutting qualities.
I I -MANUBACTIJRE 0? HIGH SPEED TOOL STEEL. Having given a b rie f account of the developement of the tool steel industry we will now pass to the present condition of manufacture of these high speed tool steels. (a) SELECTION OE MATERIALS. It has been proved from long and extensive experience that the finest qualities of crucible steel can only be made by using the best brands of Swedish of Dannemora ores, which on account of their freedom from impurities, i .e . their low precentage of phosphorous and sulphur, are rendered the most suitable for tool steels that will best retain their cutting edge. Percentages of phosphorous greater than .03 rendering the tool steel worthless. The Swedish bar iron and the blister bar, to be used in making the tool steel, after being broken into small pieces is carefully selected by the metallurgical department, where the various irons, alloys, ferros etc., are carefully weighed be fore being charged into the crucibles in the melting furnace. Before the crucible isp put into the melting furnace, it re- quires a preparatory heating, which is carried out in a sep arate furnace, placed close to the melting furnace, so’ that the crucible can be transferred from one to the other in a heated condition. The object being to prevent cracking of the crucible from sudden heating. - 4 - (b) MELTING. The necessary charges having been weighed out are now charged into the crucibles thru a long funnel or bell, mouthed tube. The melting holes are either heated by coke or by means of gas in a regenerative furnace, each division of such a fur nace bolding six or more crucibles. The process of melting occupies anywhere from three to four and one half hours, a^e according to the brand of steel being worked, the higher grade high speed steels taking a longer time tomelt and thoroughly mix the various alloys they contain. The skill of the chemists and leading melters is now brought to bear on the important operation of melting; the temperature of the furnace is regulated by them and the con tents of the crucible is inspected from time to time, so as to decide exactly when they are thoroughly mixed. It is only from long experience in melting that the correct condition can be ascertained, at which the steel is properly melted and ready for casting into ingot form. The steel being properly melted, the crucible containing it is withdrawn by a man called a "pull er-ou t". The steel having been poured into moulds and cooled, the next process is stripping the mould and topping the ingots, i.e. breaking off the ingot top, so as to reveal the fracture of the steel, by which the expert can t e ll whether the melting has been good or bad, and the ingot f i t for passing to the metallurgical department. The ingots after being carefully looked over in the melting department for outward defects are sent to the metallurgical department for chemical analysis, to -5- prove that their constitution is correct and suitable for the purpose required after which they are marked and stamped in the ingot warehouse. The steel being cast it is passed to the tilting shop, where the ingots are reheated in accordance with their different compositions and then hammered to the requir ed shape and size. These are then allowed to cool, after which they are furthur examined for defects, before passing on to the smaller hammers for tilting and finishing. (c) ANNEALING. We come now to that point in the manufacture of the steel which is most important to the user, namely, annealing. The special brands of tool steels must not only be of the highest quality but must be workable, that is , machined at lowest cost to the many designs required. Another point of importance being the necessity of eliminating internal strains, which are pro duced by rollin g and hammering. Annealing brings the steel to a uniform condition throughout the bar so that when heated for hardening equal expansion is obtained, and equal contraction when cooled in an air blast or other cooling medium, for this process the bars after being finished under the hammers and in the rollers are placed in an annealing furnace designed to heat by radiation, in which they are left from twelve to eighteen hours, according to the section of bars dealt with, at a temper ature about 1400° P, they are then allowed to cool and are labelled and placed in the ware-house ready for the market. (d) CRUCIBLES USED. Great care is required in making the crucibles in which the steel is made. These are mainly composed of plumbago together with certain other materials. They are also made from clay where it is desired that no carbon shall be imparted to the steel from the crucible. In selecting materials to with stand the high temperature necessary to insure thorough incor poration to occur with high speed steels, great care must be taken. The various fire-clays ahd compounds are carefully weighed, mixed and trodden with the bare feet and balled so as to thoroughly consolidate the mixture and free it from air spaces, thus obtaining the homogeneity required. The compound is then made into crucibles of the desired shapes and sizes. The operation of treading clay with the feet has thus far been found to be more satisfactory in every way than clay treated mechanically. To manufacture crucibles including their forma tion and drying occupies from three to six weeks, according to the size of crucible; so that the high cost of plumbago and other materials, combined with the time necessary for comple tion, renders the item of crucibles an expensive one. In steel melting the plumbago crucibles are usually made to last from e eight to ten rounds before being cast aside.
III-EFFECT OF VARIOUS CHEMICAL CONSTITUENTS. It is known that the high speed steels of the present day are combinations of iron and carbon with; 1 . -Tungsten and chromium. 2 . -Molybdenum and chromium. 3. -Tungsten, molybdenum and chromium. -7- We come now to the results obtained with steels of vary ing proportions of these elements. Mr. J. M. Gledhill of the firm of Armstrong, Witworth and Co, England, made a large num ber of experiments along this line and obtained results brief ly as follows:- (a) INFLUENCE OF CARBON. A number of tool steels were made with the carbon percent age varying from 0 .4 $ to 2.2$ and the method of hardening was to heat the steel to the highest temperature without destroy ing the cutting edge and then rapidly cooling in an air b last. By this method it was found the greatest cutting efficien cy id obtained where the carbon ranges from 0.4^ to 0.9 $ and such steels are comparatively tou-gh. Higher percentages are not desirable because great difficulty is experienced in forging the steels and the tools are inferior. With increasing carbon the steel also gets b r ittle . (b) INFLUENCE OF CHROMIUM. The next experiments were made;with the chromium element varying from 1.0 to 6.o per cent. Steels containing a low percentage are very tough> and perform excellent work on the softer varieties of steel and gray iron, but when tried on harder materials the results obtained were not so efficient. With an increased chromium content the steel becomes much hard er and greater cutting efficiency is obtained on hard materials. It was observed that with an increase of chromium there must be a decrease of carbon to obtain the best results for such percentages of chromium. The effect of substituting the more - 8- costly element vanadium for chromium, 2^ "being present, was nothing of note. It was readily forged, worked very tough and was hardened hy heating to white heat and cooling in an air blast and stood well on medium steel, but no better than the cheaper chromium ste e l. (c) INFLUENCE OF TUNGSTEN. Experiments were made with tungsten varying from nine to twenty seven percent. From nine to sixteen per cent the nat ure of the steel becomes very b r ittle , but at the same time the cutting efficiency is greatly increased, and sixteen per cent appeared to be the lim it. Between eighteen and twenty seven per cent it was found the nature of the steel changed somewhat, and, instead of being brittle it became softer and tougher, and while such tools have the property of cutting very cleanly, they do not stand up so w ell. (d) INFLUENCE OF MOLYBDENUM: This is at present under investigation, and out experi ments have produced excellent results, it is found that where a large per cent of tungsten is necessary to make a good rapid steel, a considerably less per cent of molybdenum will suffice. A peculiarity of these steels is they do not require such a high temperature in hardening, and i f the temperature is in creased above 1000® C or 1832°F the tools are in ferior and their life shortened. (e) INFLUENCE OF TUNGSTEN WITH MOLYBDENUM. It was found that the presence of from 0.5 to 7>f0 molybde num in a high tungsten steel slightly increased the cutting -9 - efficien cy but the advantage gained is altogether out of pro portion to the added cost of molybdenum. (f) INFLUENCE OF SILICON. Experiments made with the silicon content varying from a trace up to 4^, shows that silicon sensibly hardens such steels and the cutting efficiency on hard materials is increased by adding up to 3^, above that the cutting efficiency begins to decline.
IV- TEMPERING. Having discussed to some extent the effect of the various chemical compositions on the tool steel probably the next im portant factor in the high speed steel industry is the process of tempering, which to a certain extent may be said to bear directly on the chemical composition as was evidenced in the proceeding section. The method of tempering high speed steels is the proceed ing which most of a ll has distinguished this steel from a ll former brands. Where in former years steel was never allowed to be heated at any time above 1600°F or a "cherry red" without injury to its quality, we now find a piece of steel whose good qualities afe not brought forth until it has been superheated, so to speak, to a temperature of about 2200* F. The exact process of tempering high speeds tool steel var ies for the different brands, each having special methods which seem best adapted to their particular chemical composition. However, the underlying principle is the same for a ll, namely, heating to a high temperature varying from 2000° to 2200 F - 10- and then rapidly cooling in ah air blast, oil bath and some times lead bath. The e ffe ct of this high temperature is to combine the d i f f erent chemical constituents with the carbon forming, chromium and tungsten carbides or other carbides of extreme hardness. This fact alone, however, would not be sufficient for it must also retain this hardness. An ordinary carbon steel containing say 1.2 focarbon when heated slig h tly above the c r itic a l point and cooled rapidly in water becomes intensely hard, but grad ual ly loses this hardness as the temperature of frictio n reach es say 500° F. With rapid cutting steels this temperature of fr ic tio n may be greatly extended even up to 1100° or 1200° F, and it has been proved that the higher the original tempera ture of tempering is raised above the c r it ic a l point, the high er w ill be the temperature of frictio n the tool w ill withstand. M. le Chatelier in his paper on"Rapid Steel for Tools", states that:-"Steel undergoes at 700° 0(1292° F) a change of nature which has been studies in a ll its details by M. Osmond, This transformation like a great number of chemical transformations takes place with more or less considerable delay according to certain other circumstances. When heating the transformation w ill take place above 700° C, when cooling below 700* C., the quickness with which this transformation takes place at a giv en temperature is governed by a general law of chemical phenom ena, and this rapidity is so much the greater (1) as the abso lute temperature in question is highest, (2) as it is at its ii greatest distance from the point of transformation. We see - 11- therefore that apparently the higher the in itia l temperature for tempering, the longer w ill be the l i f e of the tool or the time during which it w ill retain its cutting edge. This trans formation is not only retarded by the physical change due to high in itia l temperature, but is due also to the elements of chromium, tungsten, molybdenum, vanadium and manganese whose effect is to considerabljr retard this change. This e ffe ct of high temperatures in tempering was a direct result of the work of Taylor and White at the Bethlehem Steel Works, whose discovery is best explained by the following table deduced from curves shown in Journal of the Franklin In stitu te, (Sept, 1901), which show the increase of cutting speed due to an increase in the temperature used in tempering.
TEMPERATURE 0 F 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 CUTTING SPEED. 30 40 43 35 14 16 75 93 108 120 Ft./Min.
We see therefrom that although the cutting qualities decrease immeadiately after temperatures formerly used, they increase at a much greater rate as we heat the tool still high er. Having seen that high temperatures are necessary for tem pering these steels, the question now is how best to attain this temperature with any degree of certainty, and to have the material of the same temperature throughout. All methods o f tempering can probably be classed among one of the three, heat ing by direct contact with the flame as in the ordinary forge - 12- and gas furnace, heating hy radiation as in the muffle furnace, and la stly heating "by e le ctricity which is one of the later methods and becoming much used in tempering high speed steels, especially for finished cutters such as milling cutters, reamers and dies. Following are some methods of ele ctrica l heating, the first two being mainly for lathe tools and the latter for all description of cutters. Fig. 1 shows the arrangement of apparatus. This consists of a gray iron tank of suitable dimensions containing a strong solution of potassium carbonate, to this tank is at tached the negative cable from a generator, the positive cable being attached to the metal clip holding the tool to be heated.
To harden the tool the action is as follows:- The current is thrown in by means of the switches and the current strength regulated by the shunt regulator, the tool is then dipped into the alkaline solution to any depth desired tb heat the tool, which completes the e le ctrica l circu it and at once sets up in tense heat on the immersed part. When it is seen that the tool is sufficiently heated the current is instantly switched o ff, the solution then serves to rapidly c h ill and harden the 13- point of the tool, no air blast being needed. In Pig. 2 is shown a second method of heating in this case however, the tool having to be cooled in an air blast or bath of some liquid. In this method the heat is produced by an electric arc. The method of operation is as follows:
F ’lG - Sj-
The tool to be heated is placed on the bed of nonconduct ing and noncombustibel material and the arc started gradually at a low voltage and steadily increased as required by controll- the shunt rheostat, care being taken not to obtain too great a heat and so fuse the end of the tool. When the required de gree of heat has been obtained, the current is shut o ff and an air blast directed against the tool. The source of power in this case consists of a continuous-current shunt-wound motor at 220 volts coupled to a continuous-current shunt-wound dynamo at from 50 to 150 v o lts. Arcs from 10 to 1000 amperes are then easily produced and simply and safely regulated by means of the shunt rheostat. It is in the tempering of m illing cutters and other:spec ial cutters that the greatest care must be exercised. When we consider the time spent in machining special cutters, we w ill at once see that it is extremely necessary to guard a- gainst cracking which would necessitate a duplication of this -14- tirne. To avoid this cracking it is first of all advisable to anneal the cutter after having been machined for the shocks incurred during machining produce strains in the cutters which when the cutter is heated produces unequal expansion and i f great enough cracking. Annealing w ill also impart d u ctility which will give the cutter greater powers of resistance against shock. In tempering hollow cutters of ordinary steel a heated rod was sometimes inserted to draw the temper and make the in side soft and tenacious, with this method however, there was always more or less lia b ilit y of injury. This has greatly been reduced in the following method of electrica l heating, which method is also convenient for annealing. Fig. 3 shows the general arrangement of the apparatus which consists of a continuous-current shunt-wound motor direct ly coupled to a single-phase alternating-current dynamo of the revolving field type giving 100 amperes at 350 volts, 50 cycles per second, the exciting current being taken from the work supply. The current from the alternator is reduced by means of a step down transformer to a current of 2 volts pressure, the secondary coil of the transformer consisting of a single turn of copper or heavy cross-section, the extremities of which -15- are attached to the connecting vises holding the mandrel upon which the cutter to "be tempered is placed. Although the total resistance of this circuit is low, the comparatively high re sistance of the mandrel causes the current to be used in heat ing the mandrel. As the work is put on the mandrel when cold and the heat is gradual and can be held at any desired point for a length of time the former dangers of cracking are min imized.
V-LIST or FIRMS SELLING HIGH SPEED TOOL STEEL. 1. Bethlehem Steel Co. South Bethlehem, Pa. 2. Herman Boker & Co. New York, N. Y. M frs., of Novo Steel. 3. Colonial Steel Co. Pittsburg, Pa. 4. Crucible Steel Co of Amer. Pittsburg, Pa. Mfrs. Of "Rex" Air Hardening Steel. 5. Cyclops Steel Co. T itu sville, Pa. M frs., Burgess #4 and #5. 6. Firth, Stirling & Co. Demmler, Pa. Mfrs of Blue Chip. 7. Heller Bros. Newark, N. J. 8. Houghton & Richards. Boston, Mass. Mfrs. of Styrian Steel. 9. B. M. Jones & Co. Boston, Mass. Agts. For Mushet Steel. 10. Ito. Jessop & Sons Co. New York, N. Y. 11. Edwin R. Kent & Co, 10 S. Canal St., Chicago. Mfrs., of Allen Air Hardening Steel. -16- 12. Me Innes Steel Co. Corry, Pa. Mo Innes Air Hardening Steel. 13. Geo. Nash & Co. Chicago, 111. Mfrs. Of Capitol Steel. 14. Hugo Reisinger. 11 Broadway, New York, N.Y. V ictoria High Speed Steel. 15. Sanderson Steel Co. Syracuse, N. Y. 16. Westmoreland Steel Co. Pittsburg, Pa. 17. Armstrong, Withworth Co. Manchester, England. M frs., "A. W." Steel.
VI-EXPERIMENTAL DATA OF TESTS TO DATE. Regarding experimental data of tests with high speed tool steel we find that although much has been done by manufactur ing establishments, technical schools and societies with regard to the relative value of various brands of steel when cutting different materials l i t t l e has been published giving detailed information. Experiments instituted by large manufacturing es tablishments have been of great value to themselves and their value would have been greatly enhanced i f a ll observations had been properly recorded and published. The work of Prof. J. T. Nicolson of the Manchester In sti tute of Technology has been extensivly carried on. With the aid of the Manchester Association of Engineers and other steel firms he has been able to make tests withvarious steels on different materials, finding the limits of the tools and other information of importance. A few results of these experiments are shown in Table No. 3, they being average results obtained -17- in the tests. The curves shown later are also results of these tr ia ls . The curves showing the relation between cutting speel and area of cut are interesting in that they closely approxi mate a rectangular hyperbola with asymtotes parallel to the axes of speed and area of cut. The following expression gives the relation for the six cases tested by Prof. Nicolson, viz, s o ft, medium and hard cast-iron and so ft, medium and hard steel.
V _ K - M a-L in which: a*area of cut in square inches, V= Allowable cutting speed in feet per minute, and K,L and M *• constants of which numerical values for different materials, as obtained by Prof. Nicolson, are given in the following table.
Ta b l e o r Co n s t a n t s tor E quation S howing R elatjon b et w e en Cutting S peed & A rea op Cut.
F l u id P r e s s e d S teel. Ca s t - / r o n , Constas/T-
Sorr. Med tuN. Ha r d . S o r t . Me d iu m . HARD.
K / e s J -8 5 / . 0 3 3.10 / 65 /■3C
L . on . 0 /6 0 - >6 .OZS . 0 3 0 . 0 3 5
A 1. / 5 6 4 8 7 s s
With the former curves are also given curves showing the relation between the area of cut and the force on the tool point. Immeadiately after the exhibition of Taylor and White at -18- the Paris exposition in 1900 all manner of conflicting trials were reported "by others, this induced the Berlin section of the Society German Engineers to take up the matter and they made a long series of tests which are shown in part in Table No. 1. Table No. 2 shows some results of experiments made by the tool steel firm of Bohler Bros. & Co., and are probably only a small part of the tests actually made by that company to de termine the e ffe ct of various methods of tempering and d iffe r ent chemical constituents, which howeverare not reported. Mr. J. M. Gledhill of the firm of Armstrong, Whitworth & Co., England, has also made extensive experiments with high speed steel, especially with "A. W." steel, obtaining the in fluence of different chemical constituents and of annealing. Some results of work with this steel are shown in Table No. 4 in which table are also reported a few results with twist drills. Table No. 5 is put in to show the relative endurance of the high speed, Taylor-White steel and the ordinary mushet. I f expressed in terms of the cutting speed we would find the high speed steel to withstand a speed of from three to four times that of the mushet, and considerably more than this for ordinary carbon steel. Table No. 6 is interesting in that it shows the e ffe ct the introduction of high speed steel had on the Bethlehem steel works, the company which instituted the experiments of Taylor and White which led to the discovery of the present tool steel, and goes to show the value of systematic research. Table No. 7 gives the chemical constituents of materials -19- nsed in the Manchester and Berlin experiments, which are an indication of the hardness of those materials. BOLTS OE EXPERIM ENTS M A D E B Y B e r l i n S e c t i o n , D e l 'TECHER INGEN/EURE, AT THE &ERMA A/ U o R K S .
R e t o r t e d in: r S e p t . 2 8 / 0 1 , a n d Te c h n i c s
T a b l e N o . /.
N a m e M a t e r i a l S/ZE C u t t i n g SURPACE P u p a t i o n M a t e r i a l
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B o n a e r - p /d . a .131 * ■ 0 5 0 6/ 26 • 3 0 3 9 S S 9 2
t* t* ..Z6 0 A .U '4 - 7 Z . 7 3 3 3 0 7 -s o
tt a .232 * -0 3 9 4 6 9 . 2 S 9 s S S 2 - 3 3
tt u -2 6 * 03 6 3 . 4 9 7 s o 3 - 2 2 n
a Hl ■137* N 6 4 5 - Z ■ 3 9 9 7 1 3 3 27
a * .3 4 3 * 0 6 3 4 1 - 3 . 2 / 6 7 3 s 2 . 8 2 POl-DI- *t . 2 3 Z * • t o A S 7 4 0 D/am a n t ■ 3 3 S ■ 3 1 3 2 . 6 4
B o h l f r -R a p /d it h - ■ 4 3 2 A 0 9 4 S 3/ . 6 ■2 3 7 7 2 0 4- 7/ S o h l e e , + 4 7 3 >■ O F '3 a Ti t a n - B o r e a s . / 7 - 4 . 0 7 S / 2O /A3
ti it E o n le t - p /d . . 2 5 6 *.0 3 S S ■ / s z z s o J'/O 7/\blf No. /. con-
Na m e Material -5/zr Cutt/NOSup pa ce Pupat/on Material. or Operated or Speejd- Mach/Ned OR Removed /RRMA RRS. on. Cut Mt/ Sd-RM 7R/AL ■ Lee./ 7b oc /NCHES- / M/N. /Min. NtN. 7Af/N ^TEEL. Cx\px\bl-JS oh Bohlep- Rapid Cast /poR- • 14-5 x -ISC' 7z. e /■ /07 c e 7' 3 9 Pa PTE (X A C Poldj -D/a ma -t ■'37* -'69 SO-3 ■ 7 7S &/ S-Z/ // Bohlep- p/d ■ 4* ,SZoyJC34- A 7- 3 . 7/0 /20 /y.¥3 - // /( .579 X- 37 ¥ ■ 2 3/ /ZO 6-2S * t* B/XJ&VSTAYepgiscpe ■ .55 9 X -063 37- A .22 6 /ZO y. a u Pole/-P/anant- it .szo y-JV/7 33-4- ■38 7S /ZO 7-33 it ft - .300 y-N-37 3S y . 43 4 /03 3~- 6S " Bepgjscpe-Etahl. /MPOJTTPy ■ n .5/6 xJ 33-5 .333 30 /o-ys ll - -3$ 6 *.03 £7 33-S ■ 237 /48 4*. 3/ It PoiDJ- P/A MART. *» A 37 x./04 3 z 7. 6 . 3C 6 / 90 S- 74 Boplep- Rapid Ca s t -S t e e l .ZZ65X.0&7 47-3 .280 /ZO z.y s7 1/ // // Z/G&x. 33-S H83 /ZO /■ y s •/ PoLPt - Pjama n t// 530 X -OZ7S 3 ASC .0 97 70 0 Z■ 3V 6 • Bepgiscee-Stahl / PDUJTrty- /» 39 9 X- 05!Z 260 , //83 /ZO z. /ye> II n o -ZZoSx. 086 Z/. 7 ,/SJ 733 2 . 777 - u a ■610 X - 05/Z / e-7/ . 08 6 /ZO z./ys II Bopueb-Rapid- it .530 x. oy 3z / 7- 73 , 0 & & 2* /ZO z. //s Results or Bs/re H MAOS By Bohler Bros. & Co., V/ep/s/a y Berlin . Beror ted /as: JS/sep ,v n- /_ /60! . Ta&le A/o- a! . A/AA7E MATERIAL S/ZE Cutt/po Surra ce Corat/ Rater /al or OE ‘ Orerateo Creep Mach/Ped i or eemovep /? R MA/RKLS. Tool -Steel. O/U. Cc/ T ET/ Sq.Rt/ Tr/al. ■Lee./ /A1// 'Rf/P. A7/P' • it /uches- 'M/ Bohl er-BC^ffT /RO/U.HE* .o / W .Z13 z/ . 73S Too JL Lit T A. E Ps*r*?A&EP // n ■3/S x .0787 A3- 7 .284 A z s e SAWS Tool- /s II >1 /*•£> SE ti .)77X.o 73 7 AA ■283 6-S' /■ 6 9S 7~oo i- bsot 2?A\r*7/*>G /~n>. n n Tool. I/rri5 2>**\s*7A\G & r> ■17 7A-o 98 C 2 9. .24! 30 /■ /39 / S & *?o 0 /V r>. '* H ■Z7SA ■ 038C AS 9 . 37 7 A 3-06 Too L. / 7- Ti- & -Pa* r~i a\& /- tz>. H •t ■Z7S A ■ 03 0 ■377 A.ozs Tool. /VO T Z3>a=s/^7 AtG &£? a A /S PS BIT /£\<3A\/r3- •t .2/6*. it ■ 228 z s /• 947 t> ** •t .oeSSx.oSQ/ 34--8 ■ /7/S /S ■882 it •i ✓/ .os$i/■ oue AS-2 ■ZSE 2 2 .4 0 / it «« Cast Steel ./S7x.*393 9-82 .032/ "V .2 03 IS //*/=•SVOT &PI J E22A\J^?A\ '/ X T Too &&p>. L- •i Ron&EC STEEL • °78 7 x J'3 e s c s . 970 7 z-3o GAS 2*1 E -Too t— •t /v or £>ai m a\ & & & $$ .jS7*.oS3' 37- 7 ■ 40/ S A- /a " u n ■0787 A.ofll /S7S ■ 777 z jo- 44 it «• u /378 a. 44- 7S ' /A z.se // /« ■ H8 X‘J/8 LS2-C /■SO AS AS/ 'SA*T*7 & Tool. &7VO P/Vrt. It ft 8 a .//Q 36. / .3 S3 3 S 4 oS *• tt fSOT t?/^0 prS£=>. It ti a0S1 / A-//8 /CO- /■47S 3 7-04 11 n !• ■Z 3C>*.// 83-3.3' .C2G 8 -S 729 7 It Results oeeeee8 /men te Ma d e ’ B y 8 /a h c h e s ter Muh/c/e a l S chool. oeechT mol o ox , 8 h clah d . 8 erorted jm : L on pom3m s /h £e r /hc „ Ocr-30, 03, Ma c h s h e e t , N'ov'. JO, 0 3 . Ta b l e /V o .
Tool - S t e e l Ma t e r /a l 8 / Z E C u t t / h o S cR E A CE 8 0 VUER (s U T T /H C M a t e r /a l JOu r a t / d H OE CE M a h e r . OPERATED SPEED- M a c h / h e d . E e q u / r e d 8 d m C E E e m o u e d . Te /a l ■ r C u t - S o -E 7y AT > O M ■ e t / o h T ool.. LBS./ //VGH /F&. M/H- -M /rS. T o o l - L e e . /M/h . HI/M ■ S a m e l O^gog// J5SET Sr C o - Ca s t /% ' t o 8 4 .7 . 4 4 1 Z - e o //SO S./ 7 3 ZO Mo. / TT j h t h 0 3 3 z zo tt JtS o a / E ■ *% XyP3 .5 3 4 8 . 73 3 4 7- S 3 " z MED / S a m u e l 0 C a s t %6 *y,6 4 $. , z s s Z -Z6> /3 Z o /■ 7 3 3 it tt t> y8 24-33 . 4 3 4 4 -SZ 3 8 5 0 3-SZ - 4 C Oa m m e l l Ha r d /. tt H £ C o- Ca s t %& 4 & /■za / S z 4 /. /8 5 // H - % x "£ /8 -J ./0 8 S 3-3 0 3 7 0 0 3 - o o - 6 A p m s t r o h o s o r t it IVh / t m o r t h £. Co. e t e e l . ’‘ ie. ///- .3 7 8 9./ o z 7 0 3 4 -/ 4 */ 7 H t* 0 u § x ^ 3 4 3 £ 0 16-03 3 7 ZO 7 -3 3 8 O.Oa h m e l l Me d iu m •i •t £ Co- &TEEL . 8 0 . .4/ 4 £ .6 8 Z 7 3 3 3-/7 9
amuel ’ ft tt 0 10 S % ' ye 3 4 . . ‘3 7 3 H .3 3 / o 4 5 o 3 s o Ha r d // tt ETEEL- . f z 4 /-4 ■ Z /4 3 - t o 4 0 8 0 /■ 7/ H
C- Oa MMEL tt '/ . Z 0 3 / / T 8 0 0 &. Co. ZO 8 3 3 3 . 0 0 12 TABLE 3 &■ Data F rgard/ng Tools used a t Ma n ch ester Te s t s .
Mater/a l. Front Front Tor Front SiP E True C Height o f tool. Angle. Cutting No. Ofera ake t/ng an c l e . TING AnOLE R . Clearance 60-fTop rake ABoyp Center. A r c ■ t Ceo'- sj. ON. 90'-(/3 t) (6 + tJ AngleXCX //V THIS PLAHl' N- 3 Ds. M/N. PG. M/N. PC- PcJ- + 3J- /8/ CHJZ 3 . P&- M/fJ. /f/GHJE'3 - / C^arT //?cW . 73- / 4 ' - 8 - /S 7 2 - 3 0 66- 36 O. 3 73 2 ° -6' 0-373 z 74-- /3 -44- /4 - zo 74- S3 63- 14- 0. 6 2 S 4 - 4 0 - 6 7 rtJZOI UM 3 Cs*i$T /KorS. 8 - / / 0 . 73 4 - 36 0-33 4 // 77 - Z6 /Z - 34- 8 - y o - 6 O. / 2 3 O - 3 4 0 - 6 6 m 3 C4\*T /J^orj • 76 - 28 /$~ 32* 7 9 -20 7 3 - z o 73- 46 6 . /8 7S / - 32 0 -33 & n 84- / 3 - 4/O -38 8 0 -4 6 7 7 - 4 0 O- 66
7 So FT STBS l- 70 -3 3 /e -4 2 /O - o 8 0 - O 6 / -3 4 / o o 3 - 3 7 0 -3 4 /( 8 70 - / e -4 6 8 ~ 36 8 2 - 12 6 7- 3 4 /. o o 7- 2 O-62 i um 9 %5 7~ JEZ JB? 1— ' 7/~ / /& - 48 //-2 0 8 2 -3 0 & & — ^ c. 73 3 -2 6 O. 3 3 /o n 6 3 -3 z 4 -32 7 - 3 68 - io 3 8 -2 4 O. 623 4 -3 2 0.6 73 // 6 4 -3 0 2S- 'O 6 - 4 6 6 3 -z e 0-3 73 3 -2 / o. 43 /z a 78 -7 // - 33 /!-2 0 78- 4 0 73-/6 0-3 73 4 - 3 O- 60 25
7a p l e /V /RESULT'S OPDAILY lYOff/ r A T THE Of*
/iRMSTROWG, IYh ; TVS on TP Co., P/VOLAHP , STEEL. T?EPORTEP /V . CHG Dp C . A / - 0 3 .
Ma t s r /a l R/ z p Op t t /W g SURPACP PORAT/OW OP S r e e p . P/ACH/f/ED. OP Op e r a t e d F7 PM A R K S . p w . P o t - PT/ So. P T / Tp / a l ~ //YCH&& / M/H YM M/M- S teel ARMOR- PLATE POETS. % S %*. / 3 5 ~ . 3 S 2 4 -2, O Without S teel. 7 0 Tool, / h &000 pDHG/HG. /p y ^9 . 3 4 0 S 4 '0 So/up/T/orU ■ t* W/THOO T S 3 •7 7 7 z 7 0 7=*/=GmrV&/rJ G- 0>L PAROEH J4 /& Hns. n Sort Forg 4*^6 3 7 ■ 1 9 3 S teel P Ron — Z Week■ // 0APST*w / d o T&o J- /r* (So oc? l a r g e /& O SastjHg- / x *43 4 - 0 * &Z& O &r*c>/ T/Or-/* C./.piyWheel O/UJE Toot- LZFt- P a m ■ $4 * /4 3 Z . £ 3 6 P/P/sh ed Wheel. ■
Tr ia l s m a d e w i t h Tw i s t D f z il l s .
M A T E R /A L S/ZE f f . P 7 4 - T r a v e l o p OP o p D p s r a t e d PRILL P o r a t / o h . R e m a r k s P r i l l r i l l JH s. / OH. /HCHES. P . /A 7/a / C. /. 3 L PC- CD R / JL u e- 0 o m u u s z s 3 4 u A- " / TH c m . / J HOL.0 3 . U r-l /rH U U HJz O . DRILL /Vo t f 3 3 0 V % 6 137 HOL.ES. R e g r o o m d . P RILLSD H Z 4 o it / 76 H OJ.ES S t e e l . P PFt! Ui-ED R e s u i r ZEO 5 2 7~h >Gr . / i s o H o l e s . Gr ir d /m 3 . s t e e l . S u m DRILLED 0 RA PL-E 3 0 z % 17/ 1/ H ol-ES. 26
Ta b l e / B e s u l t s o e T e s t s m a d e b e to t e
BEPRESEMTAT/VES OP 7ECHN/CAL AT Fa . Reported /m: Bmep/c a n /\uo. JB/o o .
NAME Ma t e r /a l. S jzet CuTT/MG P upa t/o/v OE OE OPE RATED S p e e d OE C u t . ET./ Tp /a e . Too/. S teel. o /v . /HCHES- / M/p. Mir/. 7Ayl or - White. VERY Ha r d Tool. STEEL /S /S // M o s h e t - H /S %
Tavloa-Wh ite Ca s t /p H b o 2 0 n M u sh et■ ft S o
S ort Tavlo/r- White. • 1 / s o \Mach, steel / s n m u s h e t . n / S o ^2
Ta b l e /Vo. e
Ta b e s s h o w /Ng ///g r e a s e / / / Cu t etc., a t
B e tree h e m S tee Co ., S//VGE //VTPODUO T/O/V OP 7a YE OP ~IVh /TE - Reported ///. A merican Mach/zvest, A ugJC - b o .
/WAY 5a/H //V % A v e r a g e . Oc t - 2 5 , Ja n . /S, 5a /tv w % /8 9 3 j e e e . j e o o Cot oe 3 r d . CoT oe3 pp. 2 f/£d. OVER /ST-
Cutting S p e e d 2 / 2 5 ^ r-r /H n u . e / £ ' 3 3 Perth or Cut /ASCRSS - 0 .2 3 0.2 73 0 .3 0 3 3 0 Fe e d 0 .0 6 5 7 0 .0 6 7 3 2 22- /ROHES . 0 -0 7 ME7AE Removed 3 1 . 5 2 5 3 3 2 '0 Lb s . p e p Hour. S '-' 3 / 3 7- 3 27
T a s l s 7 -
£/-/£/*//c a i Cpa/roj/ t/ om /tv 7^31. £ S / a ■
BOAT /7 S P / UM F a a p Ca s t JaCa s t / aCa s t / a -
B £ A L / tV. MA /VC H£S ■
Co/*7B//>f£C> C/lKBO/V o . AS % & 4 s e a/o O S Q S 7a J. / S O 7o
S r ARH/TA 3 . 4 6 Z - & 0 3 Z - 7 2 0 ).8 7 S
.5 7 /./CO Z-OS 3- 0 / 0 /• 7 0 3 1 - 7 8 3
// a r o A / v r s /■OO //8 0 0 S 8 Q 0 - 3 4 8
SU/-/=>H U R 0 / 0 0 - 0 3 / 0 0 2 / 0 - /2 /4
F h o s a a o a o o / o O-7 7 3 O S ' 2 3 0 - 7 3 2
Oa c / s a w o S t a ■ a 4 t <>73' '/3 S ~ r^7 ' . <*«/*• <5V* /N.
ST£AT£/V3 - M W h/ t w o r t h Fl u /p - Fa £ 3 3 b p . Ul-T. TAAS/1.0 J3- c Sdrr. M/FCS ! Uf*1. 26 ~ZZ^ S taaAo tas . SfQ./K *>%■ 4 -9 .//v. 26 * 3 2&-^ *’Ssc%. /V- <46-7 '/SQ./rJ. B p a u / tV. M A /VC H £3 T £ r .
Ca r b o n o. 30 O S 4 7 O. <33% 0 - /3 8 % O Z 7 S % O .S /4 %
S /u /C O /V o - o S 0 -2 / 0 -2 0 o- O S S 0 - 0 8 8 o./// FA/VPAS£3r OS 8 0 - 9 3 /-ZZ 0 - 2 0 3 0 -6 S o o - 7 3 z SOJ-RRUT? O -o S O- 02S o- o s ' o- O Z 3 0 .0 3 7 0 - 0 3 3 FnojrHono u$. o . o j o- o S o- o S O- 0 3 S' 0 - 0 4 3 0-037 70 W K
£££> X joo //a 1 20 AO /O 9a 00 0 3 o s Z do O A ■OOS AJUS yr/Al// 7oozs. /ybr-/7A/l./A/6 r o MA/JOU/SA r m r r v .
0 S O . s z .o .OR /S r o At-i. /y?£V7 y/\F*IAT/0 / \ f = t e / * y o r y/Cj&£T 7&3TJ. /yA/VC/j£&T£~T{ y\O C Hy*\rO C- a 03 - T & A/ ■ T'OT* 03 /. s wjTSiAd£A
C t o - *5V?-//✓. £<£C>6 //V • //V C t o
A/r77/V5 Sr - /*7T / o —— ---- .005 x&r r o r & rx x v A O . .O! ^ ru or o /rjun x^X M or £UT- T U £ r o A £ r ! / A 0/5 .OZ .OZS *5V?./A/. 3 Too 3 A .03 . ' m o r A /i^ /N T o o 35 l . . s 4 0 . - -045 .CS Aorce a/v Toojl - / *4-000 2000 oooo /ooo eooo 0 0 0 3 6000 3ooo 8000 7ooo o .oos 4 / -0)5 .oz -025 .03 035 .04 .04 035 .03 -025 .oz -0)5 / 4 .oos / A arirt MANCHESTER rer w / th or /O*/
£ R OR <5crrr/^& roe / A o rer > t . /v. .OS
H orce
/ =o/*c .e oaj 72>o/_ — Sooo /ZOOQ 3ooo /3 4 /o /o coo / / /ooo 6ooo //ooo 0 0 0 2 Sooo 9ooo / Sooo 7ooo 4 ooo 5ooo - / o q o 6 O 0 0 cs o 0S 0 .OBS t0Z 0/S .o/ .cos / 4 =£ £f Cu>T- £>f*/=*£A /fajR£? ~ST£rJ?l~ A?A ~ .03 z /CZ/ OS 4 OS C4S 4 ° .OSS 'P'O?. F A/*TO/ 0/* YAK//* T/OA/ p c k o ms / V y- JFp? Tfc/pu.3. f^ROM * yv/ir/i yv/ir/i A p r a
p o (P t u -3 2 -
VII UNIVERSITY OF ILLINOIS EXPERIMENTS.
The following is a description of a series of ex
periments conducted "by the writer in the shops of the Col
lege of Engineering. The experiments do not fora a com
plete series hut rather a preliminary series to determine
a method for conducting the tests and to perfect the appar
atus necessary thereto. Every effort has, however, been
made to obtain correct results and these together with the
results of further experiments to be conducted by the Engin
eering Experiment Station will be reported in a bulletin
thereof at a later date.
The work is described in the following order
A. The Tool steels Used; 3. The Cast Iron Test Pieces; C.
Details of the Tests; D. Results of the Tests; E. Conclu-
s io n s .
A. THE TOOL STEELS USED.
The following tool steels were used in these
trials:- 1 Styrian marked ’’Bonier Rapid"; 2 Mclnnes* "Extra";
and 3 "Air Novo". The steels were donated for the pro posed tests by the steel makers or their agents. The size
of the bars of steel from which the tools were made was l / 2 inch by 1 in ch . To s im p lify the t e s t s as much as possible all tools were of the same shape, as shown in pig. 4. The front clearance angle was 12 1/2 degrees, the top rake 10 degrees and the side rake 10 degrees. These angles were carefully maintained throughout the tests, by measurement with a bevel protractor during each grinding. f t £ . 4
Professor J. T..Hicolson has made a series of experiments /
relating to the proper shape of tools, and his recommenda
tions were followed to some extent.
The directions for forging and hardening the
steels were furnished by the manufacturers and are as fol-
1 ov/s: -
(1) Directions for working Styrian Steel marked "Bohler
Rapid" .
For Forging: Heat to a bright red. Do not allow the heat to run as low as a cherry-red while forging. After forging allow the tool to cool slowly before hardening.
For Hardening: Lathe, Planer and Boring Tools.
Heat to a white heat but not to a scaling or melting point, just a good white heat. Cool in the air or a cold blast.
Houghton and Richards-,
Arnerican Agents.
/ Experiments with a Lathe Tool Dynamometer.
See Trans. A. S. M. E. Vol. 25, 1904, page 658. -3 4 -
(2) Directions for working Mclnnes's "Extra" High-speed
Air-Hard Steel.
Eor Eorging and Hardening: Eorge the steel at the
ordinary tool steel forging heat; after the tool is forged
to the desired shape, reheat the cutting end to a light
cherry-red, and cool in an air blast. In order to bring
out the quality of this steel when the tool is forged to
the above instructions, it should be run at high speed in
the lathe or planer until the edge is worn off two or three
times and reground. After each grinding the tool gets
better until it gets to its limit.
Mclnnes S teel Company, L im ited ,
Corry, Pennsylvania.
(3) Directions for working "Air Novo" High Speed Tool Steel.
Eor Eorging: The steel must be heated thoroughly, so
that it is hot all the way through. The forging color must
be a very light yellow. Do not hammer the steel when it
gets down to a dark red, but reheat it. After the tools
are forged lay them down to cool.
Eor Hardening: Heat the cutting edge only of the tool
to a white welding heat. Heat it until it begins to flow.
Then put the tool into a compressed-air blast, or dip im mediately into thin lard, linseed or fish oil until thor
oughly cold.
Hermann. Boker C o .,
New York.
It is seen that all three steels are to be cooled
in.an air-blast. An apparatus was therefore designed for Separator fo r re/roi/mp pi o/5fare from 4- -/r. jo/joe-
^ H
A $ & ^
^ | i | § \ ^ s V 1 *V
* § • ^ s - X ^
^ 1 1 -3 6 -
properly cooling the tools. This is shown in Pig. 5.
The apparatus consists of a separator, for withdrawing the moisture from the air, to which is connected a header of
2-inch pipe. To the header are attached short lengths of
1 1/2 inch and 2 1/2 inch pipes which serve to concentrate the air blast on the tools placed within them to be hard ened. A rubber hose with a 1/8 inch nozzle in the end is also attached to one opening, so that a strong blast may be directed on the cutting edge of the tool when first removed from the fire. The tools were heated in an ordinary forge with a clear coke fire. Care having been taken to have plenty of coke above and below the tool to prevent cold blasts of air from striking the tool while being heated.
V II THE CAST IRON TEST PIECES
The cast iron test pieces used in the trials were donated by several manufacturers throughout the state and by the University foundry. A standard size of test piece was decided upon and blue-prints and patterns of it sent to the different manufacturers. This standard is shown in Pig. 6.
The diameter is the maximum the lathe will swing over the carriage. The test piece was made hollow; first because a solid test piece becomes too soft toward the center and is more likely to contain blow holes; second, test pieces of small diameter become springy and consequently produce inaccuracies in the results; third, the high angular velocity necessary with small diameters is undesirable. The first test piece used was 18 inches long. This was found to be r/o. 6 STANPARP f
— p o r Ji/PH-5P33P 3 OM
& A 3 T / r - 7 3 -38-
too short, the tool having to he reset too often.
In order that a comparison of results with dif
ferent grades of cast iron might he made a comparative hard
ness drill test was made on each test piece, comparison being made with a standard piece of soft cast iron of equal
density throughout.
The hardness of cast iron or any other metal as
indicated by a drill test is probably as fair an indication
of the particular quality of the metal that affects the
cutting speed as is obtainable by any process in use at the present time. This hardness test is in itself a cutting speed test in which the cutting speed is not varied, but is held constant and the rate of feed allowed to vary, the cutting speed and the rate of feed in all probability be axing some constant r e la t io n to each oth er. The t e s t s were made with a drill press as shown in Pig. 7. A constant load of
312 pounds was applied on the spindle of the drill press.by means of a weighted lever. With the spindle rotating at a constant speed of 87 r. p. m. , the rate of feed in inches per minute v;as measured, readings being taken for every 1/8 inch of depth drilled. The drill used in these tests was a Morse standard l/2-inch twist drill ground to an angle of
62 1/2 degrees. The comparison made after every trial with the standard piece of soft cast iron, eliminates any chance of error due to a small variation in the sharpness of the drill. Pig. 8 gives the graphical result of these tests, the curve drawn through the dots representing the standard cast iron and those through the circles the test pieces. Me CH. flfs/G. D ERA Ft TMEN T n * . z U N/VERE/TY OE THES/S DHAWJN6 /IRRARARUS ROE /Jarpm ees or - 4 - 0 -
7p s t P/p c p 7pst 7pST A/o. A/o. 2 0 A/O- 30 /.oo
75
.50 Jo k *
/ 2 3 / / si >4 Trsr P/pop 75s r P 75ST A/o-27 A/O-/ A/O- 2 I /.oo
3 0 / 2 7/A/P op Op /LL/A/<5 -
/yo. 3- 5bapp/oa/. 5p a b t op /7p /ll Tpptp
A/AOP oo/ 5AS 7 /boa/ T p S 7 Z^/POPP
7a b o p 7/ABPA/PSS OP 3AS7 /boa/ 7p57 7d/popp
C/mi/. ap/iL. Ob a a /PO o. Ob p a /p O o. B oot & OP ppofi/of?y d o d o Op pa P2f?PO-STPPL lOlrfPfHl/OOfTT
72s r P/pcp AVo. 2 8 2 d 3 0 2 7 / //£)ff.oa/sss //4 .3 /5 5 .0 /2 4 .2 / 3 2 .0 3 4 2 . 0 175.2 41-
The hardness of any test piece as No. 1 would then he x
100 = 342 in which .595 is the rate of feed of the drill in
to the standard cast iron in inches per minute and .174 is
the rate of feed of the drill into the test piece. The
hardness of the standard cast iron being assumed 100. The
results thus calculated are given in Table 8. A similar
method of testing the hardness of cast iron was used by
Professor J. T. Nicholson in his experiments with high-speed
toolsteels made at the Manchester Municipal School of Tech-
•nology. e
VII _C DETAILS OP TESTS
(1 ) APPARATUS
The apparatus used in the tests consisted mainly of a high-speed lathe receiving its power from a two-phase induction motor by means of belting and a counter-shaft, the power required being measured by a polyphase wattmeter. The gen eral arrangement is shown in P ig . 9. The lathe used,
Pig. 10, was a Pratt and Whitney high-speed lathe with gear box head-stock, taking a maximum length of 3 feet 9 inches between centers and a diameter of 9 inches over the carriage.
The power is transmitted from the first motion shaft of the head-stock to the cone gears by means of a long pinion and an intermediate gear, the latter being fastened to the inter mediate gear frame which swivels about the first motion shaft. e^Repo'rtf"o f.1expVriments''“made*^tTTaHcThe'steF''IfunTclpar^^ool of
Technology, London Engineering, October 30, Nov. 13, 1903.
B a cA G 65 T-/OP- 3 “ Face -
Mech. Eng . Department Un/veps/ty op Il-lim ois THESIS DRA WIN6. E r a t t anA IW/-// t n e y ft 6. /O. R/GH - SPEEO L A THE Eca/e:- /£h.*/Ft. May -/905
Cone Gears . -4 4 -
The intermediate gear frame has a substantial slide with rack, pinion and crank by which the intermediate gear is moved to any one o f foxxr p o s it io n s , in which it is lo ck e d by the dropping of a pin into suitable holes in the frame, after which movement the frame is swiveled to drop the gear into mesh with the cone gear. The latch handle at each end of the frame holds the frame and gears in position after the gears are in mesh. Prom the cone gears the power is trans mitted either direct to the spindle or through the usual back gears, thus doubling the four speeds possible with the cone gears. The speeds obtainable are shown in Table 9. The feed mechanism is positive, being driven by two gears from the main spindle through a chain of gears to the feed box change and speed gears, thence through the feed rod to the carriage.
There are eight changes possible both in the cross and lon gitudinal feeds. A reverse feed is obtained by shifting the reverse rod. Table 10 gives the feeds obtainable.
The power was transmitted to the lathe by means of a four-inch double belt from the 12-inch friction clutch pulley of the countershaft. The countershaft in turn was driven through a 37-inch pulley by a four-inch single belt from the motor. The motor is on an adjustable base, allowing changes of the motor pulley to be made without altering the length of the belt. In the tests, pulleys ranging from six to twelve- inches in diameter were used, making possible with the eight changes of speed on the lathe proper 56 changes for every diameter of work. The motor received its current from the 440 volt main of the University pov/er plant. - 4 5 -
TP/BDP
SP330P?4T/05 A/Y Si/ft PA03 OP /4ftftA ft VSPD /A/ TPSPS TV/TP 3 T P P L
v u t p SUft SACS Sft CS AZo t o p Pullsy PPVOLUT/OA/S PPft M/ Tp s t P /s c s P/AMSTSft La t a p S P3 S T P S ft OUUMTSR- La t h s D ft/us D ft/u s (Z/20 P-PP?-) D/r s c t P/ftSCT PftATT Pulls y throuch TftftOUCft Oft/US Back O DA/US Back Ot ar s 68. /O 23-43 / 6 0-3 7 3 3 -3 0 43-40 / 3-6 3 36-80 6 in . /8/. 62 90.8/ /06- 92 34-03 //• 74 80/9 27-63 2 7 24 9-38 6 4 / 3 22-09
79-46 2 7 -4 0 / 8 7- /O 6 4 -3 3 32- 97 /24- 70 43-00 7 in. 2/J.89 JO 3.94 18-26 39-73 Z3-70 93-36 32-26 3 /-7 8 JO-93 74-84 23-79
6 0-8/ 3Z-3Z 2 /3 -8 0 73-74 142-60 4 9 -Z3 Q in. 242.16 /2 /.0 3 60-34 ZO 8 7 4 3 -4 / 13-63 / 06-90 36-86 3 6 12-32 8 3 -3 3 2 9 -4 8
/ OZ ■ / 6 3 3 2 3 2 4 0 -6 0 8 2 -9 7 6 8 2 3 4 8 / 60 -40 3 3 -30 9 in. 272.4-3 / 36.2/ 3/-OQ J7-6Z /2 0 -3 0 4J-47 4 0 -8 6 J4-JO 96-23 33-21
1 /3 -3 0 39/3 26 730 9 2 /3 26/0 / 78-20 iO in. 302.70 /3 /-3 0 73-63 6/- 4 7 36-74 Z 9-36 133-60 4 6 -0 6 4 3 -3 9 13-63 / 06-90 3 6 8 6
J24- 90 4 3 -0 7 -2 9 4 -/0 701-40 8 3 2 4 28-73 196-00 6 7 6 6 Ji in. 332.97 Z66.48 6 2 -4 3 2Z3Z / 4 7-00 3 0 6 8 4 9 -9 4 Z7-/Z //7- 60 4 0 -3 2
/3 6-20 4 6 96 3 2 0 -8 0 Z /0.6 0 2/3-80 12 in. 363.24 Z8/.62 90-8/ 3/-3Z 73- 74 68- / / 23-48 / 6 0-40 3 3 -3 0 3 4 -4 9 Z8.78 /28-30 4 4 -2 3 8220S
£ft OSS 8230 LONO/TUD/NAl 8880 AftS SA P £ & <£ > & v 8220 I $ R s £ I N & § C//A/Z62 S 3 A 2 0 I 5 ? * i? I J I ft' I } ss I 1 S /A6 02A35 C/ZAN62 x o B p s t f 8 4 8 6 e p o r 0 6 8 4 O64 TO6 8 4 8 TO 3 A 78 TO 4 8 4 6 8 O34 TO 3 78 8 6 0 6 O34 TO 3 8 7 T 4 TO6 8 4 TO 2 3 0 6 O34 TO3 8 7 0 6 6 6 TO 4 6 4 6 AT V/i 'SftftftD t f t f t f S ' / 3 6 / 8 Y S / A T i/ / iV & 7 T t A f 8 044 4 70 to to to to to 4 6 82 8 44 4 64 6 32 3
5 3220 3220 5 8320 S P f t f r & : S & & & & 8 s x o B 6 S/)R s4ND s4ND Z W orm 8 L 3 4 ro/R 8220 0 8 8 * 7 t 80N ftP ^ ^ K $ * £ 8233 > 1 5 !4 «
8 / B i m K K k c a °0 t
n o
20 30ft. 3220 s s o t f C 0 ^ I -■4 sr 2032 0N2 23 3 8220 822 8 ■ 7 4 0 0208 0 2 .0 ■0322 6 7 0 0 ■ 2 8 7 0 0 0/043 4 0 / .0 8 0 3 0 .0 or r o 043/ 3 4 .0 70640 0//6 0832 3 8 .0 6 3 7 0 2 4 6 0 2 3 2 0 2 / 3 0 0/354 S pin DL 2
B2V0233/WPI2 TO /" 7ft 7ft TO/" A V£L / Z3/.6 / 27- 7 ~7576~ 8 62 86-8 8 7 4 85.7 64.3 ./ 3 4 23-2 3/J . 4 6 20.8 .0 2 3 OS /O /36 /
-4 7 -
The wattmeter used is known as the Westinghouse portable long scale indicating wattmeter for alternating cur rent circuits of either two, three or four pha^e. "In prin ciple, the wattmeter consists of a miniature induction motor, having for an armature a metal drum mounted on a shaft, to geth er with a sp rin g and p o in t e r , g iv in g in d ic a tio n s on the scale proportional to the power to he measured". "The poly phase wattmeter is a modification of the above having two drums mounted on the same shaft and revolving in two separate fields.
This construction makes a meter which is correct for two or three phase circuits under all conditions of unbalancing, low power factor, etc.,.and measures the true energy of the cir c u i t . /
(2 ) PROCEDURE I I MAKING THE TESTS: -
The test piece to be used having been brought to a uniform diameter throughout its length it was ready for the test and the tool to be used was placed in the rest in the position decided on for all tools and trials, vis., at right angles to the work with the bottom edge of the tool horizontal and the cutting edge of the tool from 1/8-inch to 1/4-inch above the center of the work, its exact position being recorded in the log. The diameter of the test piece was then accur ately measured in several places and the average recorded in the lo g . Prom a set o f curves g iv in g the su rface speed o f test pieces of various diameters, under different conditions of drive the size of motor pulley necessary to give the re-
/ Taken from instructions for the use of the Westing- house P. L. S. I. Wattmeters. -4 8 - quired speed was obtained. The change having been made and the motor started the tool was then fed in by hand until the cutting edge just scraped the bottom of the groove left by the last turning. The graduated disc on the cross feed was then set at zero and after having moved the carriage until the tool cleared the work, the tool was fed in by hand until the graduated disc showed the required depth of cut. The lon gitudinal feed or traverse was then set in position and re corded and the square case revolution counter, attached to the first motion shaft to count the revolutions, was set at zero.
The lathe was then cleared of chips and the test started, the exact time of the tool entering the work and the position of the revolution counter being recorded in the log. During the trials, readings of the revolution counter and also of the wattmeter were taken every two minutes. After the ex piration of the trial all cuttings were collected, weighed and their weight recorded in the log. To facilitate the collection of chips sheet iron guards were placed on the bed of the lathe.
(3 ) POWER ME ASUREMEHT S: -
In order to determine the power required to remove cast-iron at various speeds, the electrical input into the motor was read and recorded throughout the trials. However, to change this electrical input to horse-power'output and transmit it to the working tool required the expenditiire of some energy and a consequent loss of power. This loss due to friction and motor efficiency was obtained with the apparatus as shown in Pig. 11. The electrical input was measured by the
N o r s e - M o p v e r 5 4 0 4 3 3.0 3.5 .0 2 /■5 2.5 d A .0 I No 2j 2 af/?e 2 2j No s 2af , a'r e, f3 a 2 Ns- / .j or. r o fo N A/o./j p & jp S l i B M 5 ^ $5 rja / r o s f /r M /r?joaf I 3s e rs. j3asA gea , resf N I Aofiveer IVaffmefer & faff? &e. faff? IVaffmefer Aofiveer /? / r f/o a ///?r a 0 / . s M
Ns. 3 Ns. i Ns. 2 Ns. N /o . . /o N % — I No No ffs a W r e s u sooo £oss s o £ 0c/rr 0c/rr sfjovy/rg /2 51-
wattmeter and a prony brake placed on the test piece in the
lathe measured the horse-power output. Tests were made by
this means both with and without back gears and the power loss
measured from no-load to full-load. The results of these
tests are shown graphically in Pig. 12. These power measure
ments were -made to determine the cutting force on the point
of the tool while cutting, which could immediat&y be obtained
by multiplying the horse-power by 33000 and dividing by the
cutting speed in feet per minute.
VII D RESULTS OP THE TESTS
The results of the tests with the several brands of
s t e e l are given in f u l l in T ables 11 and 12. Table 11 g iv es
the general results regarding the sizes of cut, cutting speed,
durability, etc., as indicated by the headings of the 18’ col
umns. Table 12 gives, for the same tests, the power required
and the cutting force on the point of the tool.
The headings of the tables are for the most part
self-explanatory, however, it may be advisable to explain some
of them more fully. In Table 11; columns 4, 5 and 6 give
the speeds, depth of cut and feeds at which the trials were
intended to be carried out, while columns 7, 8 and 9 give the
actual figures obtaining during the test. The cutting speed
recorded is the speed in feet per minute of the cylindrical
surface of maximum diameter at the point of cutting. Column
10 gives the area of section cut as the product of the depth of cut and feed. Columns 12 and 13 give the area of the sur face machined. This was obtained by multiplying the cutting MrCft- S/VG- Or/=>ArTMrNT Tab lb //. Um/vebs/ ty or THESIS Exrr/=t//4r/VTs w/ thH/g h - S r r r o T o o l oa/ Ca s t J r o n
7 Z 3 •4- S & 6 7 8 \ 9 /O // /2 /3 14 IS 16 17 73 /s/aene o f fn fen d ed A C tu s/t /A rea A r e a I V e /p A t S n o se Test Surat/or fompaeate ffoed/iess grand Tr/a/ Actual o f A 7 a c 8 /n e a f r e m o v e d o f P/eoe Cut o f o f Secf/on IV/ffideaw/ Pueab/7/fy of fe of A/o. Speed and Speed 6 u f fe e d T r/a / S en F e r of 7do7 5fee/ A/0. T otal To/a! of Too/. M/cce S e e d o f £ u f M/ni/fe M/nufe T0O/ Sty . T'Mm- /n s. Sfif/n. 7ns. /n s. Sq. /e7s. ff/n . S f f t Sq.ft. L bs. L bs.
5tyr7an ZQ / 4 6 •1 ASP- %z . ozSZ .0 0 6 0 7 9 fa 0 .8 3 • 0 8 3 4 -6 o • 4 8 8 Too/ faded 0-00 ! 1 4 .6 " Z8 z 3 6 n 36.3 %z .0232 ■O0SO7 3 9 2-76 .070 / 4.40 >370 17me 0/0 7 9 4 H 4. S /' n 28 3 0 3 % * d/lZd S 4 8 Vg •0Z3 Z •00370 3 9 3. S 3 • /0 7 4 3 -6 0 /■32 O / 00.00 /14 . 6 H Z3 4 3 6 k x 262 ‘/z ■ 0 3 /2 ■0 /S 6 0 31 2 .9 2 ■ 0 9 4 SOSO /■ 6 3 0 " SO- s o / / 4 .S U n 28 S 3 0 fa* fa 3 2 6 fa .0642 .0 /6 0 0 t s % 2 .6 7 • /6 9 2 4 20 / S 3 0 /Z 90 //AS II Z0 6 6 0 % *%z 6 0 6 *8 ■ 09S2 .0 //9 0 s 2 . 36 ■472 / 0.30 2-060 " / 00-00 7 /4 .5 // // Z8 7 6 0 f/d 6 6 9 6 % ■0642 .00002 yfa 2 2 7 ■3/0 9-8z /•340 / 00.00 H 4 5 II n 2 8 8 6 0 fa S 8 o % .0 3 /2 .0 0 3 90 10 1-6 / •/S/ 6 .3 ! ■ 6 8 / /oo- 00 / / 4 . 6 II Z8 8 S o S 2 J .03/2 ■0/ / 6 0 IS 0-20 . / 3 6 2S-90 7-73 0 11 / 00.0 0 714:6 // Z8 /O SO 4 7 -4 % •03/2 • O // 6 0 8 0 9 9 •/Z 4 /Z.ZO /• 6 3 0 1/ / 00.00 //AS II Z8 // 4 0 4 / 2 fa .03/2 ■ 00 780 8 0 8 S f ° 7 6 - 7 4 ■ 8 4 2 11 /OO.OO 714.6 it Me/anes Z 9 /z AS 4 6 -2 fa .0/66 .0 0 3 9 0 30 7 8 1 • 0 6 0 /4- 40 > 4 8 0 &/2 /e s - o // z e /3 6 0 S 9 S fa .03 '2 .0 0 78 O 6 fa. 0 -9 9 ■tss 7 / 0 /■/OS TooJ failed S Z 3 /9 S O // 2 9 74 3 S fa* *64 36 A fa .0/66 .00 39 0 4 0 /• 69 ■ 047 74-70 ■367 7/me 0/0 8-16 /9 S O N oi/o Z9 76 SO ^ x ^64 47-& '4 ■ o/S8 .0 0 7 8 0 6 8 4 2 0 .0 6 2 7/90 /• 0S8 u 27-60 /96>o •• 2 9 /e 4 0 favfai 37 6 fa ■03/% .0 /6 6 0 107 fa / 0.60 ■ 0 9 7 / 8 Z - ° /• 6 9 S H Z9>20 7 9 SO Styrion 3 0 / 7 SO \2 x 7^4- 4 8 3 4z ■ 0 /5 6 .0 0 7 8 0 7 6 / JO./o .0 6 2 /0Z 'O t /32 // /oo. 0 0 /2 4 Z // Mc/nnes 3o /8 SO A£ x ^ SZ-4 fa .0 /6 6 .0 0 7 80 /z o 8 2 0 .068 / 3 o.o 7 0 8 7 /OO.OO 724-2 a Z 7 79 76 fatfa 778 l/8 .03/2 .00390 /8 ! 3 6 6 0 2 0 2 / 6 t o ■892 // /OO.OO 732.0 Tfovo Z 7 ZO 76 fa * y3Z 7 6 6 y8 0 3 /2 .00390 88jfa /7 -4 o ■/96 7 7 8 0 ■ 37 S U /OO.OO 732.0 Sfynan 7 ZJ 3 0 fa *'7e> 2&0 fa .0642 .00802 98 fa 14-70 ■149 63-20 .64-2 • t 40.00 3 4 2 0 A/oi/o 7 22 30 fa * fa 27 7 fa .0 6 4 2 .00302 97^4 /4 -4 0 ■J48 6 76 0 ■ 6 9 S V 26 30 342.0 Mefemes / Z3 3 0 fay y>6 zd.4 fa .064-2 .00802 / o /•SI •76/ 6 4 3 .6 4 3 II 2-03 3 4 2 0 /f / 2 4 3 0 % * 3 /Q y8 0 6 4 2 .00802 /o /70 •770 700 .700 Too! failed 0.00 342.0 // 7 2 3 3 0 fa* fa 3 /9 r8 .0642 •00302 (O 7 7 0 •770 7-37 • 7 3 7 lime u0 4 .0 7 3 4 2 0 S/ye/an 7 2 6 3 6 f a * fa 38-7 J e •064-2 .0040/ 8 8 /8-ZO ■ 20 7 42.00 ■477 n /7 - /0 3 4 2 0 f/o i/o 7 Z 7 4 0 fa "fa 4 0 6 y<6 ■0642 . 004-0/ 2 2 4- 77 >217 //> 8 0 ■S3 9 » 6 0 Z 34z.o // u / 2 3 4 0 ^6 *^6 43.7 fa .0642 ■ 0 0 4 0 / / 6 3 .72 •233 8 6 7 •642 6.33 3 4 2 0 /' / 2 3 AO fa* fa 4 2 6 'fa •0642 .0040/ J9 4 - 3 / ■22 7 to-30 >S 4/ u 4 90 3 4 2 0 3o n Ofyrian 7 4 o fa* fa 47 3 'fa ■0642 .0040/ / 9 k Z -98 >22/ 7-26 ■S3 8 SSO 3 4 2 0 ffoyo / 3 / 4 0 fa* fa 4 /. 7 ’fa •064-2 .0040/ 73 2 9 0 .2 2 3 6.99 >638 n S -30 3 4 z o 74& /sines 7 3 Z 3 T foy'/ie 3 0 / fa .0642 .0040/ /Z -4 o ■ '9 3 38-Zo S9 3 n /7-SO 3 4 2 0 Sfyrian 7 33 3 6 fay fa 36 6 fa ■ 0662 •0040/ S 8 ^ - //■AO . /9 6 26-80 ■AS8 n //• $ 0 3 4 2 0 TVoyo z 3 4 So fa 6 / / fa 0 6 4 2 •00 80 2 7S 3 £ 4 /. 90 •27 3 /8 9 .o 7 2 3 0 n 2 8 -6 0 7 7 6 2 Styr/en z 3 6 S o y8* f a S3-2 fa 0 6 4 2 •00807, 7 2 7 3 6-JO -284- /6 S .o 7 3 0 0 11 4 2 .8 0 /7S-Z M FC 77- E/VC. DF/=>FMTAtSA/TT)BA5 /2. U a/7 VFFS/TY /LC//VO/S T H E 3 / T Sj / Y T H ~ /^JzJz D EXFFF/MF/V ■St f f l ozv7 f a s t /r o-5 /v . Too/_ / Z 3 4 1 5/ r §_ 7 8 9 J_Q // / 2 / fa m e m orse-M ower. Cutting Force on s i z e F r e a g r a n d T e s t 7~ota/ /required A t e f ' F c t u a J Fo/nf of Too/ Fardness T rza / to d r o f o f F / e c e required C u ttin g - o f o f A/o- O u tp u t la t t e ana T o t a t F e r sg/n. C u t 7oo/ S t e e l A /o. o f M o to r for Cutting s p e e d ' F r e n T e s t Coun/ersFf. Ca/cu/ateo C u t C u fx fe ed o f c u t /-*/&€& Co/(4)-(5) M ■ 'Mm L b s . Lbs- /n s- sq.7ns. S f y r i a n ze> / z z z ■5z 0.70 45-Z 5 /z 70/000 *3Z * ^23 .00307 7 /4 .5 // z s Z O.dZ ■49 0.33 36.3 3 0 0 59300 ■00507 1 /4 .5 n ze> 3 ZSZ 787 5 4 .8 t / z 6 /2.9300 % * 3/n8 ■00870 J/4.5 •r Z8 4 2-78 ■67 Z./Z 36-Z Z9Z3 72 3 ZOO *■ . 0/560 7/4-5 n Z 3 Z. 30 S 7-67 32-5 /696 706000 '4*/,6 .0/600 7 /4 5 n Z 8 6 3. Of .70 Z.35 6 0 -5 /Z8Z 70 7800 fa*% z ■ 0//90 7745 if Z 8 7 ZZ9 -63 766 5 9 6 9ZO 7 74 80 0 .0 0 8 0 2 7 /4 5 •t z& 8 /•Z 9 ■53 0.76 5 8 -0 4 3 Z Z/0800 *6 * .00390 //4 5 n 2 8 3.08 8 ■70 Z-38 5 Z J / 5 0 8 730000 % x f* ■on 6 0 7745 n Z 3 z f z zo ■64 7-78 ■476 tZ 3 5 706500 % x ■ 0/760 7 /4 5 if z/ 23 7 4 6 ■55 0-9/ 4/-Z 7ZQ 93400 .00780 7 / 4 5 M c /n n e s 2 9 z z Z. 4 7 ■55 o.gz 46-Z 6 5 8 / 6 S 5 0 0 %X .00390 795-0 // z e / 3 2 -5 3 ■ 6 5 7 3 8 5 9 - 5 Z04Z 7 3 3 8 0 0 .0 0 7 8 0 795-0 n / 4 Z-z4 ■5Z 0-6Z 3 6 -4 5 6 Z 7 4 4 0 0 0 ■00390 /95-0 A/o y o // // Z 9 t s Z.83 .66 Z. 75 4 7 6 Z49Z 797500 4 .x *64 ■OO780 7 9 5 0 // z $ / 6 3-38 ■75 Z .8 3 3 7 6 Z 4 8 Z 7 5 9 7 0 0 ^**>2 ■ 07560 7950 S t y na n 30 /7 z s z ■65 /■87 4 8 -3 /Z 7 5 7 63500 *zx '/6 4 .0 0 7 8 0 /Z4Z Z.3Z M c tn n e n 3 0 / 8 ■ 63 7 6 8 5 Z .4 7 0 5 9 7 3 5 9 0 0 ^ x *64 .00 780 /Z4Z n 7.57 70/ Z 7 / 9 ■ 56 7 7 8 4 Z 8 709700 y3* '4 z ■00390 7 3Z O A/oyo Z7 ZO 7 4 3 4 9 7 0 0 7 5 5 4 3 7 77ZOOO fa x'^Z .00390 732-0 S T y r i a n / ZZ /SB .5 6 ZOO Z 8 o 7/79 747000 ■0080Z 342.0 tV o Y o / Z z /SO ■56 7 / 0 Z7-7 73/0 763500 *6 x */6 ■ 0 0 8 Oz 34Z.O M e t n n e s / Z 3 A 3 3 ■58 7 Z 5 2 8 4 745/ 78/000 fa x * ,6 . 00802 3 4 Z 0 ft / Z 4 / 90 ■59 7 3 / 3 / 8 7 3 6 0 769800 y8 * 'i6 ■00802 34Z.Q n / 2 5 7 8 7 ■59 ZZ8 3 /■ 9 73Z 5 765300 ■00 8 0 Z 342-0 S t y na n / z e /■z9 '5Z 0 - 6 7 3 8 . 7 5 7 / 74Z300 */6 xie> .00401 34Z0 /Vo y o / Z 7 7-48 .5 5 0.93 40. 7 7 5 4 7 8 8 0 0 0 ■00407 34Z0
// / 28 7S7 5 7 7/0 43-7 8 3Z ZO7000 M e ■0040/ 342.0 a / 2 9 7 4/ ■54 0-87 4 Z S 6 7 5 76 8 ZOO */6x'7f6 ■00407 34Z.O fy L S ty r / o n / 3 0 752 ■55 0-97 47- 3 7 7 3 79Z500 /l6 * //6 ■ 00407 3 4 2 -0 /V o v o / 3 / 7 4 Z ■ 5 4 0 -8 8 4J- 7 6 9 7 778500 ■0040/ 3 4 2 0 Z Z 4 M e / o n e s / 3Z ■53 0-7/ 36-Z 6 4 9 767600 *i6 x*i6 .0040/ 342-0 S f y r i a n / 3 3 7 Z 9 . 4 7 0 8 2 3 6 .0 7 3 9 734 0 0 0 .0040/ 3 42 -0 A/o y o £ 3 4 Z./3 ■6/ 7-5Z 57. Z 9 0 Z 7ZZ500 %xtj£ •0 08 OZ 775Z S f y r i a n Z 3 5 7-76 ■58 /■ZO 53- Z 7 45 93000 fax*i& .0 0 8 0 Z 775-2 -5 2 -
speed in feet per minute by the feed in feet per revolution of
the spindle. Columns 14 and 15 give the weight of cuttings
as obtained from the actual weight of the material removed.
Column 17 gives the com parative d u r a b ilit y o f the t o o l . An
entirely arbitrary standard of durability was established as
follow s:- A tool whose cutting edge was worn away .002 inches
after one hour of use was considered perfect, its durability
being expressed as 100. The ratios of the durability of any
other tools to the standard will then be the inverse of the
ratios of their rates of wear to the rate of wear of the stan
dard. The wear as assumed for the standard is shown in Fig.
13 at x* In the experiments, ;* however, the distance a was measured and x then calculated.
The headings for Table
12 are self-explanatory, columns
4, 5 and 6 giving the horse power required and columns 8
and 9 the consequent cutting
fo r c e as obtain ed by c a lc u la
tion from the horse-power and cutting speed.
VII E CONCLUSION.
The results of the tests as reported in the forego
ing Tables 11 and 12, while not admitting any decided con
clusions, do however, warrant a few statements to be made re garding this new tool steel.
The cutting speeds possible are from two to three -53-
times as great as those possible with the use of the water
hardening carbon steels.
There is considerable variation in the allowable
speeds for various grade of cast-iron, and the probability is,
that there is a direct relation between the hardness of the
iron and the cutting speed which might be expressed by a curve.
Such a curve has not as yet been obtained.
The point of maximum speed for different grades of
iron seems well defined, above this speed the tool breaking
down very rapidly while below it, after the first sharp edge
has worn away, the tool lasts a long time.
Variations in the results obtained with the same
brand of steel seem to indicate a non-hornogenious material.
ITo one of the steels tested showed any marked superiority over
the others, probably due to this variation.
Before, however, the best there is in these steels
is obtained, shop methods must be readjusted and advances must be made in the way of better furnaces for tempering and heavier machine tools designed with especial reference to high speed
work. -5 4 -
BIBLIOGRAPHY.
(1) American Machinist, Dec. 22, 1904.
Developement and use of High speed Steel.
J. M. Gledhill.
(2) Technics. June & July 1904, p. 591.
High Speed Tool Steel: Its manufacture and use.
J. M. Gledhill.
(3) Journal franklin Institute. Sept. 1901.
The Taylor-White Process of Treating Tool steel
Charles Day.
(4) Zeitschrift des Vereines Deutscher Ingenieure.
Sept. 28, 1901.
Report of Experiments instituted Ly the Berlin
S e ctio n .
(5) Stahl and Eisen. Jan. 1, 1901, p. 26.
Experiments with a new Tool Steel.
E. H e is s ig .
(6) London Engineering. Oct. 30 & Hot. 13, 1903.
Report of experiments made at Manchester Munic
ipal school of Technology.
Prof. J. T. Hicolson.
(7) London Engineering. Dec. 4, 1903.
"A. W" Rapid Cutting Tool Steel.
J. M. Gledhill
(8) Stahl and Eisen, Jan. 15, 1903.
High speed Steel.
E. R eiser -5 5 -
(9) Proceedings Institute Mechanical Engineers.
July, 1903.
Uotes on High Speed Tool Steel.
Henry H. Suplee.
(10) .American M a ch in ist. Mar. 5, 1903.
Speeds, feeds and angles of Metal cutting tools.
H. P. Donaldson.
(11) Technics. 'Jan. 1904.
Rapid Cutting Steel.
Prof. J. T. Hicolson.
(12) Transactions American Society Mechanical Engineers
Volume 25, 1904.
Experiments with a Lathe Tool Dynamometer.
Prof. J. T. Hicolson.
(13) London E n gineerin g. Aug. 21, 1903.
Rapid Tool Steels.
(14) London Engineering. Mar. 4, 1904.
The Introduction of High Speed Steels in
E ngineering Work Shops.