,,transcriber',s ,,note ,some minor misspellings in the text are silently corrected4 ,enclosed small caps in double tilde1 enclosed italics font in underscores1 bold text in equal sign4 ,the numbering of the drawings does not correspond to their marked number4 ,however1 they have been left as they are1 as the author has entered them by hand in the drawings4 ,in the table on the color of the oxide layer of tempered steel in the tempering section1 the first column has been set without trailing commas1 as the author has handled this inconsistently4 ,the new original cover art included with this e,book is granted to the public domain4 ,a ,,few ,,secrets ,,of ,,the ,,metallurgist ,,simply ,,told ,,atlas ,,crucible ,,steel ,,co4 ,,publishers ,,dunkirk1 ,n4 ,y4 ,a ,,few ,,secrets ,,of ,,the ,,metallurgist ,,simply ,,told ,,by ,,gerald ,w4 ,,hinkley1 ,m4 ,e4 ,,cornell ,,university ,,ordnance ,,engineer ,,and ,,assistant ,,to ,,president ,,atlas ,,crucible ,,steel ,,co4 ,,dunkirk1 ,n4 ,y4 ,,first ,,edition ,,copyrighted #aiah ,,by ,,press ,,of ,,dunkirk ,,printing ,,company ,,preface4 ,this is not and is not intended to be a thoroughly complete explanation or discussion of the allotropic theory of iron and steel1 but rather a brief outline of a few of the great principles of metallurgy written primarily for the layman4 ,if without leading him astray from the real scientific understanding of the subject we have succeeded in briefly but satisfactorily answering the old familiar question1 8,why do steels harden801 we will in a large measure1 have accomplished our purpose4 ,besides the personal observations which the writer has made from time to time in the metallurgical laboratory1 he has availed himself freely of the works of many and eminent authors dealing with this subject and where disputable conditions have arisen in regard to certain theories1 uses1 etc41 has attempted to adopt the most logical consensus of opinion4 ,g4 ,w4 ,h4 ,,contents4 ,a ,,few ,,secrets ,,of ,,the ,,metallurgist ,,simply ,,told4 ,page ,,introduction #ag ,,chapter ,i4 ,a ,slight ,test of the ,imagination #ai ,,chapter ,,ii4 ,comparison ,between ,conditions ,which ,exist in the ,iron and ,steel ,family to ,those ,which ,exist with ,more ,familiar ,elements #bb ,,chapter ,,iii4 ,an ,experiment ,performed with a ,piece of ,pearlitic ,steel #bi ,,chapter ,,iv4 ,high ,speed ,steel #ea ,,chapter ,v4 ,the ,general ,effect of the ,more ,important ,elements in ,tool ,steels #fa ,carbon ,steels #fa ,alloy ,steels #fc ,high ,speed ,steels #fd ,elements ,which ,occur in all ,steels #ff ,iron #ff ,carbon #fg ,manganese #fg ,silicon #fh ,phosphorus #fi ,sulphur #gj ,elements ,which ,have ,become ,especially ,associated with ,special ,alloy ,steels #gj ,chromium #gj ,tungsten #gb ,molybdenum #gc ,vanadium #gc ,cobalt #gd ,uranium1 ,titanium and ,aluminum #ge ,impurities #ge ,heat ,treatment #gf ,hardening #gg ,annealing #gi ,tempering #ha ,conclusion #hd ,,chapter ,,vi4 ,what ,tool ,steel ,is ,doing ,towards ,winning the ,war #he ,,appendix4 ,analysis1 ,uses and ,heat ,treatment of ,various ,grades of ,tool ,steels #ib ,high ,speed ,steels #ic ,die ,steel for ,hot ,work #id ,special ,alloy ,steel #ie ,semi-,high ,speed ,steel #if ,simple ,carbon ,tool ,steel #ig ,non-,shrinking ,oil ,hardening ,steel #ih ,special ,hot ,work ,alloy ,steel #ii ,a ,,few ,,secrets ,,of ,,the ,,metallurgist ,,simply ,,told ,,introduction4 ,when as a student at a ,technical ,college of one of our great ,universities1 ,i came to the study of ,differential and ,integral ,calculus1 ,i remember that ,i was seized with a kind of mental paralysis at the thought of the great unknown that lay before me4 ,fortunately1 however1 a little book was brought to my attention1 under the encouraging title 8,calculus ,made ,easy04 ,as a matter of fact the little volume did not attempt to take its readers through all the intricacies of the entire subject1 but it did succeed in giving a certain start on the long journey which has to be undergone by a student of the ,calculus4 ,its opening sentence was encouraging1 which ,i have always remembered1 and which read something as follows3 8,what one fool can accomplish1 another fool can do1 therefore take courage04 ,this same thought applies to the subject which is now before us4 ,,chapter ,i4 ,a ,,slight ,,test ,,of ,,the ,,imagination4 ,we live in a world in which certain conditions of the atmosphere and the so-called elements surrounding our daily existence1 are entirely familiar to us4 ,from force of habit we are likely to forget that had ,nature1 for instance1 been planned under a different range of livable temperatures1 all the familiar objects of our daily existence would have existed under entirely different form4 ,for instance1 if the normal temperature had been about #bgjj degrees ,fahrenheit instead of about #fj degrees ,fahrenheit1 and we had been constructed so that we could comfortably endure that degree of temperature1 we could have gone sailing on a sea of molten iron1 in boats built of plumbago crucibles1 and oars made of silica brick4 ,under these delightful conditions we could place frozen lumps of our sea of iron in our ice boxes for refrigeration4 ,flat irons and stove lids would therefore have been the product of the ice man4 ,the water with which we are now familiar1 of course1 could not exist in its liquid form1 or even as steam1 but instead as a highly gaseous state1 which we would probably have been called upon to breathe4 ,certain other substances with which we are perfectly familiar in our daily life1 such as the common stick sulphur1 for instance1 would exist in an entirely different physical state1 although their chemical properties would be entirely unchanged1 and we would be given to understand that an 8allotropic0 transformation had taken place4 ,if we can now imagine ourselves as existing under the relative conditions described above1 which are undoubtedly the 8natural0 conditions of some other world1 it will then be easy for us to understand quite clearly some of the other 8allotropic0 forms of iron and steel than those with which we are at present familiar4 ,,chapter ,,ii4 ,,comparison ,,between ,,conditions ,,which ,,exist ,,in ,,the ,,iron ,,and ,,steel ,,family ,,to ,,those ,,which ,,exist ,,with ,,more ,,familiar ,,elements4 ,one of the first physical changes which we would discover would be that when we desired to 8freeze0 a 8crucible0 pailful of our iron water1 we could do so much more easily if the same were in its absolutely pure state than we could if it were mixed with some other element1 such as carbon4 ,of course1 we have long known that this is the case with water and salt1 and just as it becomes harder and harder to freeze water with greater and greater percentages of salt mixed with it1 so the freezing of iron with greater and greater percentages of carbon mixed with it1 would also occur at lower and lower temperatures4 ,if we started to add salt to a pail of water we1 of course1 would have different degrees of brine4 ,just so with the addition of carbon to a crucible of pure iron1 we would likewise have different degrees of the resulting mixture4 ,in adding the salt to the pailful of water1 we would arrive at a point where the water had absorbed all of the salt which it was capable of holding at room temperature4 ,if we had added a little less salt we would have had free water in excess of salt1 and if we had added a little more salt it would have been impossible for the water to have dissolved it1 and we would1 therefore1 have had salt in excess of water4 ,for convenience we will call the mixture above mentioned1 at which the water had become thoroughly saturated with the salt1 8cementite01 because this is the name which our friends1 the metallurgists1 have given to a similar mixture of iron and carbon4 ,they call the water1 8ferrite02 the salt1 8carbide0 and the resulting mixture of brine1 8cementite04 ,this mixture of iron and carbon always exists in exactly the same ratio1 namely1 #ic4d iron and #f4f carbon1 and is expressed chemically by the symbol ,fe#c;,c1 which means1 in other words1 that three 8atoms0 of iron have united with one 8atom0 of carbon to form the 8chemical compound01 8iron carbide01 which the metallurgists1 as above mentioned1 desire to term 8,cementite04 ,now let us go back to the brine solution with which we are already familiar1 and suppose that we added a little more salt than the water could absorb1 and which therefore would exist in a 8solid solution01 and then bring this 8mechanical mixture0 to such a low temperature that it would actually 8freeze04 ,for convenience1 and in order to agree with the metallurgists again1 let us call the resulting structure 8pearlite04 ,that is the name which they have given to a corresponding 8mechanical mixture0 of cementite and ferrite4 ,this new constituent 8pearlite0 contains approximately ,o4#i carbon and consists of inter-stratified layers or bands of ferrite and cementite4 ,it is regarded as a separate and distinct constituent of steel1 and takes its name from the fact that it has a mother of pearl-like appearance under the microscope4 ,it always occurs at a definite range of temperature and always contains the above mentioned definite percentage of carbon4 ,from the above it may be suspected that a steel containing ,o4#i carbon1 consisting entirely of pearlite1 forms rather a special and particular class of steels1 which the metallurgists have decided to dignify with the title 8,eutectoid ,steels04 ,having done this much to properly impress the unsuspecting probers of their secrets1 they decided to call steels containing less than this ,eutectoid ratio of carbon 7#j4i ,c7 8,hypo-eutectoid ,steels04 ,these steels1 of course1 contain certain definite amounts of pearlite with other amounts of free or excess ferrite4 ,likewise1 if the carbon content is greater than ,o4#i there will be an excess of cementite over the ferrite and we will then have a structure of pearlite plus free cementite4 ,and these steels are spoken of as 8hyper-eutectoid0 steels4 ,illustration3 ,hypo-eutectoid ,steel4 ,carbon 4#aa4 ,structure3 ,light--,ferrite2 ,dark--,pearlite4 ,mag4 #ejjx ,illustration3 ,hypo-eutectoid ,steel4 ,carbon 4#cg4 ,structure3 ,light--,ferrite2 ,dark--,pearlite4 ,mag4 #ejjx ,illustration3 ,eutectoid ,steel4 ,carbon 4#ij4 ,structure3 ,fine uniform ,pearlitic condition4 ,mag4 #ejjx ,illustration3 ,hyper-eutectoid ,steel4 ,carbon #a4bj4 ,structure3 ,dark--,pearlitic2 ,white boundaries--,cementite4 ,mag4 #ejjx ,,chapter ,,iii4 ,,an ,,experiment ,,performed ,,with ,a ,,piece ,,of ,,pearlitic ,,steel4 ,however1 let us not trouble ourselves with too many definitions at one time1 but instead amuse ourselves for a while by running through a little experiment with a piece of carbon tool steel similar to that which we have just been discussing4 ,for our investigation we will also need a special kind of thermometer for measuring high temperatures4 ,such an instrument is known as a 8pyrometer04 ,now we will drill a little hole in the test piece of carbon steel and after inserting the 8couple0 of the pyrometer into it1 place the same in the electric furnace4 ,as the current is turned on1 the test piece begins to grow warm and then hotter and hotter1 gradually up through a range of temperatures which are continually recorded by the needle of the pyrometer4 #hjj1 #ijj1 #ajjj1 #abjj degrees ,fahrenheit are uniformly reached1 and the temperature of our test piece continues to rise1 as the absorption of heat progresses4 ,suddenly1 however1 the test piece assumes a bright glow and the needle of the pyrometer ceases to advance1 and we note that it is pausing at about #acej degrees ,fahrenheit4 ,then after its pause1 the advance is again resumed until the piece has become almost ready to melt4 ,by plotting the uniform periods of time at which we read the different temperatures recorded by the needle of the pyrometer1 against the temperatures as read1 we would have a picture of our phenomenon something as follows3 ,illustration3 ,graph showing the course of the temperature curve as a function of the heating time of the metal sample4 ,now let us begin to let our test piece cool off gradually4 ,the temperature of the furnace is lowered and the uniform range of cooling temperatures is recorded by the ever sensitive needle of the pyrometer4 ,suddenly as before1 the test piece assumes the brilliant glow noted previously1 and again the needle comes to rest1 but this time we note that the recorded temperature is about #abej degrees ,fahrenheit instead of #acej degrees ,fahrenheit as before4 ,evidently there has been a certain tardiness or 8lag0 which has caused the phenomenon to take place a little too high going up and a little too low coming down1 and in fact the metallurgists tell us that such is exactly the case1 and that the real point in which we are interested lies just half way between the two points indicated1 as we shall presently see4 ,if we again represent the results of our latest experiment graphically1 we would have a picture something as ,fig4 #b4 ,illustration3 ,graph of the cooling curve of the metal sample over time ,now placing the second curve so obtained on the first1 we are able to study the following interesting relationship4 ,fig4 #c4 ,illustration3 ,graph combining the heating- and cooling-curves from before and demonstrating the critical range ,it is natural to suspect that both of the parallel sections of our curves have something to do with the same thing1 and for convenience since we noticed that mysterious glow of the test piece just as the needle came to rest1 we might call the particular point which lies just half way between the temperatures under discussion1 the point of glow1 or as the metallurgists call it1 the 8point of recalescence0 and the range between these two temperatures the 8critical range04 ,i suppose it would be difficult to explain this phenomenon of the test piece unless we imagine that as the critical range is reached some internal reaction of the steel causes it to spontaneously take on heat at the same temperature in the first place and give off the stored heat at the same temperature as the piece was being cooled down1 and this heat caused it to glow as was noticed4 ,now if we were to experiment further with our piece while at the critical range1 we would find certain other remarkable changes1 one of the most noticeable of which is the loss of magnetism at and above the critical range4 ,irons and steels are usually the most magnetic materials1 but the attraction of the magnet is completely lost at or above the critical range4 ,we can easily satisfy ourselves in this respect by noting the attraction of a simple horse shoe magnet when our piece of test steel is brought into its magnetic field4 ,as the pyrometer needle passes on up through the range of temperatures noted above1 the magnetic attraction is perfectly evident when suddenly the recalescence point is reached1 the spell is broken and the magnet and the test piece fall apart4 ,but let us just consider this phenomenon a moment4 ,we are told by the physicists that magnetism is induced in a piece of iron or steel by a 8rearrangement of the internal molecular structure1 in which the positive ions face one direction and the negative ions in the opposite direction04 ,therefore1 if magnetism suddenly ceases to exist it would seem as if something had happened to the 8internal molecular structure0 of the test piece4 ,thus when the recalescence point is reached we may conclude that something more than a mere absorption of heat units has taken place4 ,in fact we may really believe that an actual internal molecular revolution has occurred and that some of the natural laws which formerly had governed all of these little molecules which go to make up the whole piece of steel1 have been overthrown and that the molecules are more or less free to set up a new form of government for themselves1 and that1 therefore1 when a piece of steel is brought to the recalescence point it is really in a very sensitive condition4 ,in fact1 if we should care to investigate further we should find that certain other great changes take place at this critical point1 such1 for instance1 as partial failure of the test piece to conduct an electric current1 which formerly1 of course1 it did with great ease4 ,also when the critical range is reached1 a peculiar contraction of size interrupts the gradual expansion which had been developing as the test piece absorbed heat units1 and therefore these several observations give us reason to believe that our conclusions as noted above must be more or less correct4 ,now if all steels acted exactly like the little test piece which we have been observing above as they were placed in the hardening furnace1 it would not take us very much longer to finish our preliminary investigations4 ,you remember the piece of steel which we have been investigating was a piece of simple carbon tool steel1 containing about #j4ij carbon4 ,but all steels do not contain just this same percentage of carbon1 and may also contain various elements other than carbon1 all of which produce many and varied results during the process of heating1 treating and hardening4 ,in order to better visualize the investigation which we are making1 let us picture graphically each step which we take4 ,if therefore1 we let the vertical lines represent the different carbon contents which steel might have1 and the horizontal lines the different degrees of temperatures through which we might desire to heat the steel under discussion and then plotted the phenomenon described above we would have a picture something as follows3 ,illustration3 ,graph showing the point of recalescence ,now all that picture means is that as we heated up a piece of simple carbon tool steel containing ,o4#i ,c1 we discovered a certain very noticeable reaction which occurred just about half way between #abej degrees and #acej degrees ,fahrenheit1 which we decided to call the point of recalescence1 and then on further heating of the piece no other such phenomenon was noticed4 ,now let us go through the same experiment with a piece of steel containing 4#de ,c4 ,yes1 just as before1 as the temperature #abej degrees ,fahrenheit is reached we note all the strange symptoms which are characteristic of the point of recalescence and then1 just as we are about to decide that it is hardly necessary to go further we notice that the pyrometer needle has again come to rest1 but that this time it is registering #acij degrees ,fahrenheit4 ,therefore1 it would seem as if this piece had two critical ranges instead of one and we are now quite ready to again proceed with our heating to see if anything else occurs4 ,however1 as nothing does happen we turn to our picture and plot the two points just observed1 together with the one point found on our first investigation1 and the drawing then looks something as follows3 ,illustration3 ,graph additional shows the recalescence of a second sample containing a different rate of carbon ,now let us take a piece of carbon steel as before1 but this time containing 4#ae carbon1 and again proceed with our observations4 ,again the needle of the pyrometer records the point of recalescence and also the point designating the second range of critical temperature1 but this time strange to say1 as the test piece continues to absorb heat1 a third critical range is registered1 all of which when added to our former picture gives a result something as follows3 ,illustration3 ,graph showing different behavior of samples containing different rates of carbon ,by repeating the operations as outlined above1 with pieces of steel containing various percentages of carbon from zero to #a4be and by plotting the different critical temperatures so obtained1 we finally obtain a chart which graphically expresses the critical ranges of iron and steels due to the variation of the carbon content4 ,with very low carbon steel it is interesting to note that the first critical point would not occur until #acie degrees ,fahrenheit was reached4 ,metallurgists have long designated the lines so obtained by letters1 8r01 standing for1 8refroidissement01 which is the ,french word meaning 8cooling01 the suffixes #a-b-c simply standing for the lines in the order drawn4 ,from the completed chart it is further evident that our first piece containing #j4i carbon in one way is the most interesting of all since it is the only case where only one point of critical temperature occurs4 ,it will be noticed from the chart that steels containing less than 4#aj carbon have no point ,ar#a and it is therefore undoubtedly due to the carbon content that this1 the point of recalescence1 occurs4 ,from tests which we made with the magnet we would also find that the temperatures at which loss of magnetism occurs are those designated by the line ,ar#b1 whereas the loss of ability to conduct an electric current occurs at the point designated ,ar#c4 ,in steels containing 4#de carbon to 4#ge carbon loss of magnetism and loss of ability to conduct an electric current occur at the same points designated on our chart by the line ,ar#c-b2 whereas in the steel containing 4#ij carbon--all these changes take place at the same time4 ,now1 as we concluded before1 it is evident that some internal change must have taken place in the steel itself1 and as we know that the chemical content does not vary1 it is further evident that the change must be of a physical nature1 or as in the language of the ,metallurgist1 an 8allotropic change04 ,therefore1 another conclusion which we can draw at this point is that a very much more thorough investigation is required for the proper handling of steel at high temperatures than a mere knowledge of the chemical analysis of the same4 ,there is one very fortunate circumstance connected with the passing from one of these allotropic changes to another1 and that is that the effecting of one of these changes takes time4 ,it does not take a very long time1 however1 for in some instances the change is affected in a very small fraction of a second1 while rarely more than one or two seconds are required4 ,the higher the temperature the quicker the change4 ,would it not be interesting if we had been so constructed as outlined in the beginning of this little volume2 that we could have withstood the high temperatures in which some of these very interesting changes occur1 because we could then handle the steel1 examine it and experiment with it at our leisure4 ,however1 such not being the case1 we will have to derive some other means for 8catching0 the steel while it is in one of these interesting conditions1 and then bringing it in its entrapped condition down to room temperature4 ,how shall we do it8 ,well1 we remember that we said it took time to effect the changes under discussion and furthermore we remember that the changes can only take place when the steel is within the proper critical range4 ,therefore1 if we could do something to lower the temperature of a piece of steel while in one of the critical ranges before the steel had time to effect the usual allotropic change of form1 we might be able to catch a piece of steel while in one of these unusual conditions1 before it had really had time to get back to normal4 ,therefore1 let us place a piece of 4#i carbon tool steel in the heating furnace and bring it up to and beyond the point of recalescence4 ,now1 grasping the piece firmly in a pair of tongs with all possible speed we plunge it into a nearby pail of ice water1 keeping the steel constantly in motion4 ,almost instantly the steel becomes black and within a few seconds is actually brought down to room temperature4 ,now let us take the steel out and examine it4 ,the act of tapping it on the anvil in order to knock off the surplus water gives us a hint that our test piece has undergone some sort of a change4 ,for now it rings with a bell-like clearness and gives the hammer with which we strike it a quick snapping rebound which in itself indicates great hardness4 ,next1 we test the piece with a hardened steel file with which we could easily have made a deep ridge before we attempted the heating operation and to our surprise the file has as little effect as if it had been made of wood4 ,and to our surprise on closer examination1 we actually find that our test piece has scratched the file--surely it must be very hard4 ,we are convinced that some marked change must have taken place4 ,what can it be8 ,why it must be that due to the rapid cooling in the pail of ice water we brought the temperature of the test piece down below the critical range before the abnormal condition at which it existed while at and above the critical range had found time to change back to its former condition4 ,and we remember that if one of these allotropic changes is going to take place at all1 nature says it must do so while the steel is within the critical range and therefore having forced the steel through that critical range which separates one allotropic condition from another1 before it had found time to effect its desired change1 we managed to entrap the abnormal condition so that we could see it and feel it and get familiar with it at room temperature4 ,if we so desire we can now make other hardness tests on our piece of steel at our leisure4 ,for these scientists have invented several machines4 ,one of the most common is called the scleroscope in which a hardened steel ball is allowed to drop from a given height on to the piece of steel to be tested4 ,then the rebound of the ball is carefully noted4 ,the higher the rebound1 the harder the piece4 ,that is natural isn't it8 ,we know that if the ball were allowed to drop on butter1 it wouldn't rebound at all1 because the butter is so soft4 ,a piece of wood would possibly record a very tiny rebound1 while a piece of hardened tool steel would effect a very material action of the scleroscope ball1 thus indicating extreme hardness4 ,now let us take our test piece to the grind stone and grind it down to the shape of a cutting tool4 ,it is necessary to resort to the grind stone1 in order to get the desired shape1 because of course1 our test piece is far too hard to cut with any other metal4 ,after having produced a tool of the desired shape and size1 let us fasten the same securely into the carriage of a lathe1 and then upon applying the cutting edge to a revolving piece of cast iron1 or soft steel1 or even to a piece of the very same grade of steel out of which the tool was made1 only while it is still in the softened or annealed condition1 we find that it is capable of easily and quickly cutting out a good sized ribbon of chips from the metal which is to be machined4 ,however1 we are soon confronted with a new difficulty1 for as the cut progresses1 our tool runs into a rough spot which causes it to tremble and chatter and then suddenly our tool cracks in two in the middle and is at once completely ruined4 ,it is evident that as we are able to increase the desirable element of hardness in a piece of tool steel1 we also automatically increase the undesirable element of brittleness1 and therefore some new method must be devised which will allow a sufficient degree of hardness to allow the tool to cut other metals and at the same time not cause so much brittleness that it will crack in two at the first rough spot which it encounters4 ,one method of assisting the toughening of a piece of hardened tool steel is accomplished by the process of 8drawing04 ,this simply means heating the piece of hardened tool steel up to some fairly warm temperature1 which of course must be kept well below the critical range 7at which the steel would jump at the chance to quickly change back into one of its softer allotropic forms7 and then keeping the steel at this drawing temperature for a while until the unusual strains and stress caused by the rapid cooling have had an opportunity to have become somewhat relieved4 ,therefore1 the process of 8drawing0 is quite as important as is the first act of hardening itself1 and great care must be exercised in undertaking the same4 ,,chapter ,,iv4 ,,high ,,speed ,,steels4 ,after the processes of hardening and drawing our sample of simple carbon tool steel have become thoroughly mastered1 it might seem that all which was desired had been accomplished and that we could go on indefinitely making and using our simple carbon steel tools4 ,however1 when the extraordinary demands of modern industry required faster and faster cutting speeds1 and deeper and deeper cuts1 we commenced to realize that our familiar carbon tool steels would not fill the bill4 ,this was due to the fact that as the tools became pressed with the faster speeds and deeper cuts1 they could not do their work without becoming over-heated by the friction caused by the work of upsetting the chip and therefore the critical temperature was rapidly approached4 ,of course we know that if this temperature should be reached the steel would quickly lose its hardness and its cutting edge would therefore be completely ruined4 ,therefore1 it was necessary to develop a new kind of steel to meet a new and severe condition and accordingly the mother of experiment and invention gave birth to the now famous 8,high ,speed0 ,steel4 ,the general principles applying to the hardening and drawing of ,high ,speed ,steel are in many ways the same as described above for the simple carbon steel1 except that as we begin to add various elements other than carbon to the melt1 the resulting alloy becomes more and more complex in its form and reactions and therefore its heat treatment causes greater and greater study and skill in its successful undertaking4 ,it is generally known among tool hardeners that it is necessary to heat the tool to a higher degree of temperature in order to secure proper hardness when using ,high ,speed ,steel than it is when a simple ,carbon ,tool ,steel is employed4 ,we are told that the introduction of certain elements into the melt of a simple ,carbon ,tool ,steel has the tendency to change the critical range4 ,of course1 the formulas used in the manufacture of any high grade ,high ,speed ,steel contain very appreciable amounts of various elements other than ,carbon which materially effect the property which the steel will have when hard4 ,the effect which these elements appear to produce in the period of critical range can be seen from figure #g4 ,illustration3 ,,heating ,,and ,,cooling ,,of ,,high ,,speed ,,steel ,,shown ,,in ,,fig4 #ab4 ,in this case an experiment was made with a piece of ,high ,tungsten ,high ,speed ,steel similar to the experiment which was described in detail above with the test piece of simple ,carbon ,tool ,steel4 ,the readings of the pyrometer were carefully recorded and when plotted on the graph sheet produced the picture under discussion4 ,here it will be noticed that the vivid reaction1 which we might have expected would occur as the temperature indicating the first critical range was reached1 was materially reduced4 ,this might lead us to suspect that the desired allotropic change had not completely taken place at this point4 ,in fact we noticed that the pyrometer needle did not record a vivid critical point until a very much higher temperature was reached4 ,all of these observations serve as a possible explanation or indication of why it is necessary to employ very much higher temperatures in the hardening of ,high ,speed ,steel than it is in the hardening of a piece of simple ,carbon ,tool ,steel4 ,in a later chapter of this little volume we define ,carbon ,steels as those which do not contain enough of any element other than carbon to materially affect the physical properties which the steel will have when hard4 ,high ,speed ,steels which are one of a very important group of special alloy steels1 are those steels to which some element other than carbon has been added in sufficient amount to materially effect the physical properties which the steel will have when hard4 ,the element which stands out alone as the most vital and important one as affecting the wonderful and highly desirable features looked for in ,high ,speed ,steels is ,tungsten4 ,we will discuss the various effects which the different elements give to the different alloy steels in a later chapter1 but for the present we will confine ourselves to a brief discussion of the heat treatment of the now famous modern ,high ,speed ,steel4 ,illustration3 ,high ,speed ,steel4 ,carbon 4#eh4 ,structure3 ,very fine pearlitic condition1 with particles of free carbide4 ,mag4 #ejjx ,as previously suggested the pressing demand of modern industry for quicker work1 greater efficiency and enormously increased out-put of product1 gave rise to the necessity of producing far more remarkable tools than was possible with the old fashioned carbon tool steel4 ,therefore it became necessary to produce a steel which could be rendered sufficiently hard to cut deep furrows in the various metals which have to be machined and1 which could be made sufficiently tough to stand the enormous cutting strains and chatter and vibration of the machine1 and at the same time maintain all these characteristics when the work done by upsetting the chip of the machined member actually rendered the cutting edge of the tool red hot4 ,after the seemingly impossible task of producing a steel to meet these terrific conditions had been successfully accomplished1 the next question which arose was to produce a machine which was sufficiently powerful to stand the work done by the tool1 and so fast has been the progress made by the tool steel producer1 that many of our modern manufacturing industries of today are constantly having to introduce new and heavier machinery into their various machine shop and tool rooms in order to keep pace with the possibilities of the tool made from the modern ,high ,speed ,steel4 ,now1 if we were to run an experiment with a test piece made from ,high ,speed ,steel similar to the one which we ran on the simple ,carbon ,tool ,steel1 we would find that many of the same phenomena previously noticed would again be recorded4 ,probably the most important difference would be the fact that instead of having to quench the same in water it would be desirable to use a bath of oil4 ,in fact1 water would cause the ,high ,speed ,steel to cool off far too quickly so that it would be likely to crack and be rendered useless4 ,a peculiar action of the various elements in ,high ,speed ,steel is very likely to materially retard the change of one allotropic form into another4 ,in fact1 the change is so slow that after a piece of ,high ,speed ,steel has been heated above the critical temperature1 it will actually retain its hardened or austenitic condition even if allowed to cool in the air1 and it would only be possible to get it back into its softened condition by the lengthy process of annealing4 ,annealing is the process of undoing exactly what the act of hardening accomplished4 ,long tubes are filled with the tool steel bars and sealed from the air and then placed into the annealing furnaces1 wherein the annealing temperature is maintained for a sufficient number of hours1 until the steel has had an opportunity to become thoroughly softened4 ,as before stated 8drawing0 or 8tempering0 means the careful re-heating of the steel to #djj degrees ,fahr4 to #fjj degrees ,fahr41 thus allowing a slight 8slipping0 of enough of the higher allotropic solution to a lower form1 which it is always eager to accomplish at temperatures near the point of recalescence4 ,this1 of course1 relieves the excess brittleness of the hardened steel4 ,annealing is the complete release of the higher allotropic form of the solution and the 8trapped0 carbon which allows of their return to the normal condition of pearlite and alpha iron4 ,therefore1 it is necessary to heat the steel above the point of recalescence and cool more or less slowly4 ,different speeds of cooling give different grain1 size1 structure and physical property4 ,this explanation of hardening1 which is known as the 8allotropic theory0 is not universally accepted1 although it is difficult to find a better or more complete explanation of the remarkable phenomena involved4 ,however1 the fact remains that the great accomplishments which have been made by the men of science and understanding have caused remarkable results to have taken place in the manufacturing world of today and the fine and obscure lines which these patient and careful laborers are continually drawing upon the map of knowledge are doing much to make the world a better and safer and more wonderful place in which to live4 ,,chapter ,v4 ,,the ,,general ,,effect ,,of ,,the ,,more ,,important ,,elements ,,in ,,tool ,,steels4 ,we know that all metals of engineering nature are crystalline in character1 that is1 the crystals form when the metal solidifies4 ,if these crystals were free it would be easy to determine definitely just what properties the metal would have4 ,however1 the crystals are not free1 but exist in the steel in combination with many other types of crystals4 ,this results in many complicated and complex possibilities in the finished product1 and will bring us presently to the subject of 8,alloy ,steels04 ,,carbon ,,steels4 ,carbon ,steels are those which do not contain enough of any element other than carbon to materially affect the physical properties which the steel will have when hard4 ,carbon is one element used above all others by manufacturers in getting required physical properties4 ,an increase of one hundredth of one per cent 74#ja7 gives a tensile strength of about one thousand pounds per square inch1 but even this amount of carbon also regularly decreases the ductility of the finished product4 ,when steel is heated red hot and plunged into water1 the carbon in the metal unites with the iron in some peculiar way so that it produces a compound of extreme hardness4 ,if the steel contains nine-tenths of one per cent 74#ij7 of carbon1 a sharp point so quenched will almost scratch glass4 ,with one per cent 7#a4jj7 of carbon it reaches nearly its limit of hardness4 ,now carbon steels with this percentage carbon can be used for some of the harder tools1 which do not require much ductility or toughness1 but with higher carbon contents than this percentage1 the brittleness increases so fast that the usefulness of the metal is decidedly limited4 ,therefore1 when the steel must meet requirements other than just that of hardness1 such as1 strength1 ductility1 toughness1 resistance to repeated shock1 8red hardness01 etc41 then it is necessary to resort to other means and combinations for obtaining the required needs4 ,it is to be remembered that such methods and combinations will materially increase the cost of the final product4 ,,alloy ,,steels4 ,what is an alloy steel8 ,the general definition of an alloy steel is1 8a solidified solution of two or more metallic substances04 ,the ,international ,committee upon the nomenclature of iron and steel defines alloy steels as 8those steels which owe their properties chiefly to the presence of an element 7or elements7 other than carbon04 ,this latter definition more nearly applies to our case1 but it must be born in mind that the distinction between an element added merely to produce a slight benefit to ordinary carbon steel1 and the very same element added to produce an alloy steel itself1 is sometimes a very delicate one4 ,for example3 ,manganese is added in amounts usually less than #a4ej to all ,bessemer and ,open-,hearth ,steels1 for the purpose of getting rid of oxygen1 and neutralizing the effect of the sulphur4 ,but this does not produce an ,alloy ,steel4 ,when we make 8manganese steel0 containing #aj to #bj manganese1 the material then has properties quite different from the same steel without the manganese1 and we then have a ,manganese ,alloy ,steel4 ,thus1 for our purpose1 we may consider an alloy steel as being one to which some element other than carbon has been added in sufficient amount to materially affect the physical properties which the steel will have when hard4 ,,high ,,speed ,,steels4 ,high ,speed ,steels are perhaps the most important of alloy steels1 and derive their name from the fact that they can be used as cutting tools when the cut on the machined member is being made at a high speed4 ,this1 of course1 subjects the tool to severe operating conditions1 which simple carbon steels could not stand4 ,these steels have other notable characteristics1 among which is that of 8self-hardening0 or 8air-hardening01 as it is sometimes called4 ,this means1 when the steel cools naturally in the air1 from a red heat or above1 it is not soft like ordinary steel1 but is hard and capable of cutting other metals4 ,another striking characteristic of high speed steels is their ability to maintain a sharp cutting edge while heated to a temperature far above that which would at once destroy the cutting ability of a simple tool steel4 ,because of this property1 a tool made of high speed steel can be made to cut continuously at speeds three to five times as great as that practicable with other tools4 ,the result of the friction of the chip on the tool may cause the tool to become red hot at the point on top where the chip rubs hardest1 and the chip may1 itself1 by its friction on the tool1 and the internal work done on it1 by upsetting it1 be heated to a blue heat1 or even hotter4 ,,elements ,,which ,,occur ,,in ,,all ,,steels4 ,there are certain elements which are practically always found in any kind of steel4 ,these elements are capable of producing many varied effects on the finished product4 ,they are ,iron1 ,carbon1 ,manganese1 ,silicon1 ,phosphorous and ,sulphur4 ,,iron4 ,the base of all steels is ,iron4 ,it goes without saying that this element should be obtained in the best and purest state possible4 ,probably the best 8base0 iron comes largely from ,sweden1 which country seems to have produced the highest quality of iron on the market today4 ,,carbon4 ,carbon has already been discussed under ,carbon ,steels1 although1 of course1 its importance in ,alloy ,steels must not be under-estimated4 ,the proportion of carbon aimed at in high speed tool steels is about #j4fe1 which in simple steel would not be enough to give the maximum hardness1 even if the steel were heated above the critical point and quenched in water1 and still less so when the steel is cooled as slowly as these steels are in their treatment4 ,this shows that the carbon element acts in a different way from what it does in simple carbon steels as previously discussed4 ,,manganese4 ,manganese ,steel is a typical self-hardening steel and so1 obviously1 is any steel which is in the austenitic condition at atmospheric temperatures1 that is to say1 whose critical temperature is below atmospheric temperature4 ,thus1 self-hardening steels are non-magnetic4 ,because of its low-yield point1 manganese steel does not give satisfaction in many lines1 for which otherwise it might be eminently fitted4 ,manganese used in small quantities 74#cj to #a4ej7 will produce certain desired effects4 ,under these conditions it acts as a purifier4 ,and when added in the form of ,ferro ,manganese to a heat of steel it unites with the oxygen and transforms it to slag as oxide of manganese4 ,there is also good reason for believing that manganese prevents the coarse crystallization1 which impurities such as ,phosphorus and ,sulphur would otherwise produce4 ,five per cent to #ad manganese renders the steel non-magnetic as well as a poor conductor of electricity4 ,,silicon4 ,the dividing line between silicon-treated steels and silicon-alloy steels is not clearly defined1 but the latter are used for several important purposes4 ,such steel has been used in springs of the leaf type for automobiles and other vehicles1 the silicon being considered to add slightly to the toughness of the springs4 ,however1 the most important use of steels of this type is probably in the manufacture of electrical machinery4 ,it is possible to produce a silicon-alloy steel which has not only a greater magnetic permeability than the purest iron1 but also1 a high electrical resistance4 ,its hysteresis is1 of course1 low1 this property always accompanying a high permeability4 ,it therefore is a very valuable material for use in electro-magnets1 and in electric generating machinery1 is the most efficient material known4 ,in silicon-treated steels1 the silicon is used somewhat as a scavenger1 although it also produces results somewhat similar to manganese4 ,,phosphorus4 ,phosphorus has little effect upon the hot properties1 but in the cold state makes the steel brittle and is of course highly undesirable although some writers have claimed that it adds to the tensile strength in about the same degree as carbon4 ,,sulphur4 ,sulphur has just the opposite effect of ,phosphorus1 and makes the steel crack while it is being hot worked1 although after the metal is cold it seems to have no particular effect upon the physical properties4 ,,elements ,,which ,,have ,,become ,,especially ,,associated ,,with ,,special ,,alloy ,,steels4 ,such elements are3--,chromium1 ,tungsten1 ,molybdenum1 ,vanadium1 ,cobalt1 ,uranium1 ,titanium1 ,aluminum1 etc4 ,,chromium4 ,chromium is an indispensable constituent in modern high speed steel1 and does not make a poor high speed steel1 even when used alone4 ,the chief effect which chromium produces in high speed steels is undoubtedly that of 8hardening04 ,however1 chromium1 like carbon1 will produce brittleness1 if added in too large quantities1 although if kept down to between #b to #e it seems to allow the lowering of the carbon element1 while at the same time maintaining the desired hardening effect1 without causing undue brittleness4 ,the great hardness in the face of an armor plate1 and the great toughness in the back of the plate1 also the superb properties in the projectile which attempts to pierce the plate1 can all be induced in chromium steels to a degree unattainable by the use of any other single element4 ,as a simple chromium steel the product may be used in five-ply plates for the manufacture of safes4 ,these plates are made of five alternate layers1 two of chrome steel and three of soft steel1 and after having been hardened1 offer resistance to the drilling tools employed by burglars4 ,hardened chromium rolls are manufactured for use in cold-rolling metals4 ,files1 ball and roller-bearings are other noted products of this type of steel4 ,it is the essential constituent of those steels which neither rust nor tarnish4 ,,tungsten4 ,it was soon found that the composition of 8self-hardening0 steels was not the best one for high speed steels4 ,tungsten was discovered as an element which gave the steel properties of hardness and toughness at a red heat4 ,after the peculiar heat treatment had been learned1 and the presence of manganese or chromium in addition to the tungsten was shown to be unnecessary in appreciable amounts1 it was found that more durable qualities could be obtained by increasing the percentage of tungsten1 while at the same time the carbon element was greatly reduced4 ,the best grade of ,high ,speed ,steel ought to have a tungsten content of about #ah4jj and a carbon content of about #j4fe4 ,thus whenever a steel is needed which must operate under especially severe conditions1 this would be the steel to use4 ,such conditions are usually met in the case of rapid turning1 boring1 planing1 slotting and shaping tools1 also with twist drills and all forms of milling cutters1 gear cutters1 taps1 reamers1 special dies1 etc4 ,,molybdenum4 ,molybdenum was once thought of as being somewhat in a class with tungsten1 but its use in high speed tool steels is being generally discontinued4 ,the reason for this is that it was found that in rapid steels this element caused irregular performance1 such as large variations in the cutting speeds which they would stand4 ,this element is also likely to make the steels seamy and contain physical imperfections4 ,molybdenum steels were also found to crack on quenching1 and possess decided variations in internal structure4 ,,vanadium4 ,vanadium steels are still in their infancy4 ,therefore1 the true value of this element in rapid steels must probably be held as not yet fully determined4 ,with the single exception of carbon1 no element has such a powerful effect upon steel as vanadium1 for it is only necessary to use from #j4aj to #j4ae in order to obtain very noticeable results4 ,in addition to acting as a very great strengthener of steel1 especially against dynamic strains1 vanadium also serves as a scavenger in getting rid of oxygen and possibly nitrogen4 ,it is also said to decrease segregation1 which we may readily believe1 as most of the elements which quiet the steel have this effect4 8,vanadium ,steels0 demand a somewhat higher price than do those steels which do not contain this element in appreciable amounts4 ,it is1 of course1 especially useful for all purposes where strength and lightness are desired1 such as springs1 axles1 frames and other parts of railroad rolling stock1 and automobiles4 ,,cobalt4 ,the valuable effect of cobalt is claimed to be that it increases the red hardness of high speed tool steel1 enabling the steel to cut at a higher speed4 ,however1 this element much resembles nickel1 which has been largely condemned as not being a desirable ingredient for high speed tool steels1 because it has the effect of making the edge of the finished tool soft or 8leady04 ,,uranium1 ,,titanium ,,and ,,aluminum4 ,these elements are generally classed as scavengers1 although recently important claims have been advanced for their effect upon the physical properties of steel4 ,this is especially true for the first two4 ,in present practice1 however1 they are used almost entirely as deoxidizers or cleansers1 and are added to the metal for this purpose only4 ,,impurities4 ,phosphorus1 ,sulphur and ,copper are the most noted impurities which occur in steel4 ,the first two are practically always present in greater or smaller amounts as the case may be4 ,the best processes of tool steel manufacture are capable of producing steels with no copper4 ,while ,aluminum is not generally classed as an impurity1 it nevertheless sometimes shows up in the finished product when its presence is not desired1 and therefore1 might be considered an impurity4 ,combinations of iron with some or all of the above elements in the form of slags and oxides are other well known impurities4 ,from the forgoing pages it must be evident that producing a steel with exactly the correct chemical content is only one step towards securing a satisfactory product4 ,however1 it might be well if we were to briefly sum up a few of the more important features of our discussion on this interesting subject4 ,,heat ,,treatment4 ,the heat treatment of tool steels is of the utmost importance4 ,tool makers of the old school proved their ability to accomplish certain desired results in the art of heat treatment without really fully understanding exactly how or why they were able to do so4 ,today1 however1 progressive manufacturers are using the results of research and such thorough scientific investigation that the process has become far more complicated and complex1 and the results obtained are correspondingly more remarkable4 ,chemically perfect steel may be easily and completely ruined during the process of melting1 cogging1 rolling1 hammering1 annealing1 heat treating and tempering4 ,it is the business of the steel manufacturer to carefully guard his product up through the process of annealing1 but it usually falls to the tool maker to undertake the delicate operations of heat treatment and tempering4 ,,hardening4 ,the application of heat alone to steel can very materially affect the condition of the structure of the metal1 either with or without simultaneous mechanical treatment4 ,depending upon the degree of heat1 the rate of heating and cooling and the duration of such treatment1 this application may be decidedly beneficial or harmful as the case may be4 ,we now know that when steel is heated above the critical point1 and is then allowed to rapidly cool1 a very marked hardness in the metal is produced4 ,the degree of hardness so attained will1 in general1 vary directly with 7#a7 the percentage of carbon1 7#b7 the rate of cooling1 7#c7 and the temperature above the critical point from which the cooling takes place4 ,when the steel comes from the rolling mill and from the finishing hammers it is in this hardened condition4 ,therefore1 in order to render it soft and ductile enough to cut and work up into certain desired shapes1 sizes and tools1 it is necessary to subject the steel to the process of annealing4 ,this operation is usually undertaken by the steel producer1 under which circumstances he is able to control his product through this delicate procedure1 and deliver the same to his customers in the best possible condition for their use4 ,,annealing4 ,annealing has for its object3 7#a7 ,completely undoing the effect of hardening1 leaving the steel soft and ductile 7#b7 refining the grain1 in which case the crystals are allowed to re-arrange and re-adjust themselves1 usually growing to a rather large size 7#c7 and removing strains and stresses caused by too rapid cooling4 ,such cooling strains are particularly likely to exist where the rate of cooling is different in different parts of the bar1 but the process of annealing ought to remedy any such condition1 leaving the steel soft1 ductile and of refined and uniform crystalline structure throughout4 ,the process of annealing is easier to explain than it is to actually put into practice4 ,the steel is first packed in lime1 charcoal1 fine dry ashes or sand1 and then sealed in long air-tight tubes or boxes4 ,the whole receptacle is next slowly brought up to a dull red heat1 of about #aejj degrees ,fahrenheit4 ,it is very important to heat the material uniformly all the way through1 and then hold it in this condition from three to eight hours4 ,thus1 allowing the slipping of one allotropic condition into another4 ,the receptacle must be cooled equally slowly1 either allowing the packed steel to cool slowly down with the furnace1 or by placing the same in a soaking or cooling pit1 which also accomplishes the desired result4 ,after the receptacle has become entirely cooled it is opened and the steel unpacked and removed4 ,the steel is then ready for its final inspection before shipping to the tool maker4 ,,tempering4 ,the process of tempering usually has to be undertaken by the tool maker or user after the annealed steel1 which he received from the steel mill1 has been cut up and shaped into the desired form and size4 ,the main object of tempering steel is to re-harden the material to such an extent that it will cut other metals1 retaining its desired shape size and cutting edge1 while at the same time it must not possess too much brittleness4 ,the treatment varies materially with different brands of steels4 ,for the average grade of the best ,high ,speed ,steel containing from #af to #ah tungsten1 the tool should be brought very slowly up to a dull cherry red4 ,it is usually considered good practice to first place the tool near or on top of the pre-heating furnace before actually placing it in the pre-heater1 in order that the heating might be effected just as slowly as possible4 ,the pre-heating operation should bring the tool up to about #afjj to #ahjj degrees ,fahrenheit1 after which the tool should be placed in the high heating furnace and brought up to #bcjj to #bdjj degrees ,fahrenheit1 or a white sweating heat4 ,care should be taken not to allow the tool to remain in this condition for more than an instant1 as it is then in a very critical condition and could be easily burned or ruined4 ,therefore1 the tool should be immediately pulled from the furnace and plunged into a good clean oil bath1 keeping it constantly in motion4 ,as ,high ,speed ,steels are air-hardening steels1 it is also the practice to harden these steels by simply placing the cutting edge in an air blast1 which produces maximum hardness in the desired point and allows the body of the tool to cool at a little slower rate1 thus slightly relieving the cooling strains and producing a little less brittleness therein4 ,such cooling strains can be relieved throughout the whole tool by drawing the same back to about #djj to #ejj degrees ,fahrenheit1 and sometimes as high as #ajej degrees ,fahrenheit1 depending upon the particular tool and its use4 ,the treatment of ,carbon ,steels varies with each particular brand4 ,great care must always be taken to heat the steel uniformly1 as a material which is heated unevenly will expand and contract unevenly and1 in consequence1 will crack when quenched4 ,the steel should always be hardened on the rising heat1 in general bringing the same slowly up to a dull cherry red1 or to about #adej degrees ,fahrenheit1 and then quenching in clear cold water1 keeping the same in motion until the steel is cold4 ,the temper should then be drawn according to the purpose of the tool1 which could only be discussed for each particular case4 ,the following range of temperatures are interesting1 as being approximately indicated by the thin film of oxide tints which occur on the tool undergoing a tempering operation3 ,pale ,yellow #dbh ,degrees ,fahrenheit ,golden ,yellow #dfi ,degrees ,fahrenheit ,purple #eca ,degrees ,fahrenheit ,bright ,blue #eej ,degrees ,fahrenheit ,dark ,blue #fja ,degrees ,fahrenheit ,,conclusion4 ,the effects of annealing1 rolling1 hammering1 treating and tempering are best understood by those manufacturers who make a specialty of supplying a high grade tool steel1 and in general it would be well if customers would consult freely with the producers of these steels1 before attempting the delicate undertaking of ,heat ,treatment4 ,,chapter ,,vi4 ,,what ,,tool ,,steel ,,is ,,doing ,,towards ,,winning ,,the ,,war4 ,it hardly seems fitting that we should close these pages without giving our readers some little idea of just what the tool steel industry is doing for the successful conclusion of the great cause nearest our hearts4 ,one of the first statements which we could make would be that every metal worker in the world absolutely requires some form of tool steel or special alloy steel in the manufacture of his product4 ,of course1 a very great many manufacturers other than the actual metal workers also need this same supply of tool steel in order that their production might not immediately cease4 ,volumes could be written on the vital importance of tools to industry in general1 from the drills which drill out the hole in a hypodermic needle1 to a twelve-ton drop-forge steam hammer4 ,but for the present we may confine ourselves to simply the briefest mention of the vast number of iron and steel products actually and vitally engaged in the prosecution of the war4 ,we are told that we need ships1 yet the ship industry could not proceed a day if its supply of necessary tools was cut off4 ,the overwhelming increase in the manufacturing operations of the world which has taken place since the opening of the ,european ,war can better be imagined than explained1 it being only necessary for us to point out here that the one absolute necessity which is common to all and required by all branches of such vast manufacture is the proper supply of necessary tools4 ,it has been the personal duty of the writer to make various visits to different ,government shops and ,arsenals as well as to the plants and shops of torpedo1 shell and munition manufacturers and the vital part which the tools of production are playing in the great undertaking has been forcefully impressed upon his attention4 ,the metals which are destined to play an active part in actual warfare are naturally required to meet the most severe conditions imaginable4 ,thus we find the high manganese armor plate and the high chrome-manganese armor piercing projectile4 ,we find the new specifications for steel forging1 for hulls and engines now have rigid chrome-vanadium and special nickle requirements1 all of which means that the tools that do the machining1 planing1 shaping1 cutting1 drilling1 boring1 reaming1 stamping and many other operations must be made of a tougher and harder material than ever before4 ,we know that for every man who may fight on the battle field1 at least two men must labor in our shops and factories over mechanical operations4 ,those of us who have been in immediate touch with some of the vital requirements of the ,war and ,navy ,departments in these strenuous days realize the shocking absence of the complete preparedness1 which we must rapidly accomplish if we are to come anywhere near supplying our own soldiers on the fighting front with the fighting machinery and supplies of which they are in such urgent need4 ,we realize that after all these months of increased industrial preparedness1 we are1 therefore1 still unprepared in the full meaning of the word4 ,the very foundation of our structure shows a startling amount of unpreparedness4 ,we like to gaze upon the exterior towers and battlements of a castle of preparedness1 and these are wonderful and encouraging to look upon but down below all these are certain neglected and unfinished pillars in the unseen cellar of that foundation1 which threaten the stability of the entire mass4 ,it is1 therefore1 some of these fundamental details which have been neglected as we have beheld the vision of the super-structure above4 ,pershing needs1 #a1ejj1jjj boys in khaki and over the shoulder of each is his protection against the ,hun4 ,everyone of these rifles is a splendid monument of the accomplishment of tool steel and special alloy steel4 ,every day of our present existence it happens that over a million shells scream over the miles of battle line in ,france4 ,this curtain of high explosive and shrapnel is another direct expression of the wonders which the modern high speed and special alloy steel have accomplished4 ,we are told that a #c8 shrapnel shell contains seventy drilled holes or a drilling of #ai-a_/d0 in depth4 ,that means that #a1fjj1jjj feet or over three hundred miles of drilled holes are shot away every twenty-four hours on the battle fronts of ,europe4 ,in a publication 8,fighting ,industry0 published by one of our largest twist drill companies in this country1 we note that the drilled holes in various implements of our militant harness are as follows3 #h8 shrapnel shell #gj ,springfield rifle #id ,torpedo #cdff ,machine gun #cej ,aeroplane #djhi #c-ton auto truck #eidf ,light ambulance #aejj #c0 field gun #abhj ,gun caisson #eid ,anti-air craft gun #abjj ,self-binder #ejj ,thresher #dbj ,motorcycle #aafj ,four million men must work with tools in order that two million men may fight in ,france4 ,these men can not1 8just be given a tool and told to use it40 ,it is necessary that they have years of careful training and actual experience in order that they might effectively make use of the intricate tools and machinery which the mother of modern industry is striving to place in their hands4 ,at present every tool steel mill in ,america is straining its furnaces1 hammers and rolling mills to their maximum capacity4 ,they are working days1 nights and ,sundays and still the demand is far in excess of the supply4 ,conservative estimations show that with all the added machinery and equipment which is in the process of construction at this time1 it will still take at least two years and a half before the tool steel industry of ,america will come any where near meeting the demand for its product4 ,as we gaze with belated pride upon the huge structure of our present ,preparedness1 does it not seem strange to think that the most vital pillar of its whole foundation should have been forgotten and neglected so long and which is therefore now caused to endure such an abnormal and terrific strain8 ,we are at last forced to realize that tool steel is the very essence of our whole existence4 ,of course1 the great importance of tool steel in this national emergency does not stop with the actual weapons of warfare4 ,besides the railroads1 automobiles1 tramways1 elevators1 bridges1 buildings1 shoes1 clothing and in fact1 every branch of the intricate mass of manufactured products so vital to our daily existence1 nations are crying for bread4 ,victory hangs on our food supply4 ,our threshing machines1 our reapers and our harvesting machinery are all working over time4 ,but before the threshing machines can thresh wheat and before the reapers can reap and before the tractors and other farm machinery can contribute their great service to humanity1 it is necessary that the ,american production of tool steel must pass its rigid inspection and yield forth in full measure the great service which it is called upon to give4 ,,appendix4 ,,analysis1 ,,uses ,,and ,,heat ,,treatment ,,of ,,various ,,grades ,,of ,,tool ,,steels4 ,providing the many complications and difficulties which accompany the melting1 hammering1 rolling1 annealing1 inspecting and finishing operations1 have been successfully accomplished1 the chemical analysis of the best grades of tool steel should come within the following limits3 ,,typical ,,analysis ,,of ,,high ,,speed ,,steel4 ,carbon 4#ff ,tungsten #ah4ja ,chromium #d4ej ,vanadium 4#ih ,phosphorus 4#jbc ,sulphur 4#jba ,manganese 4#bhe ,silicon 4#bbh ,iron 7by deduction7 #ge4bic ,,uses4 ,turning1 ,boring1 ,planing1 ,slotting1 ,shaping ,tools4 ,also ,twist ,drills1 ,milling ,cutters1 ,gear ,cutters1 ,taps1 ,reamers1 ,special ,dies1 etc4 ,,heat ,,treatment4 ,heat slowly in pre-heater to #agjj degrees ,fahrenheit4 ,then rapidly in superheater to #bcjj degrees ,fahrenheit1 taking care not to burn or fuse delicate projections on special tools4 ,harden either in air blast1 or in good clean oil2 keeping tool in motion4 ,in all cases merely the end of the tool to white heat4 ,draw in oil from #djj degrees ,fahrenheit to #fjj degrees ,fahrenheit4 ,,typical ,,analysis ,,of ,,die ,,steel ,,for ,,hot ,,work4 ,carbon 4#ci ,tungsten #h4da ,chromium #b4aj ,phosphorus 4#jai ,sulphur 4#jag ,manganese 4#cae ,silicon 4#bcd ,iron 7by deduction7 #hh4eae ,,uses4 ,hot shear blades1 hot punches1 header and gripper dies2 used in bolt and rivet making4 ,also excellent for compression sets and in general for all hot work4 ,,heat ,,treatment4 ,will stand high hardening heats1 similar to high speed steel1 #agjj degrees ,fahrenheit and then #bcjj degrees ,fahrenheit4 ,harden either in air or oil4 ,keep away from water4 ,draw to #ejj degrees ,fahrenheit4 ,,typical ,,analysis ,,of ,,special ,,alloy ,,steel4 ,carbon 4#gh ,vanadium 4#bi ,phosphorus 4#jad ,sulphur 4#jaf ,manganese 4#cbd ,silicon 4#bif ,iron 7by deduction7 #ih4bh ,,uses4 ,specially useful in tools subject to shock1 such as hand and pneumatic chisels1 boilermakers caulking tools and rivet sets4 ,also for cold upsetting dies1 cold punches1 shear blades and stamping dies4 ,a special grade of this steel makes excellent taps4 ,,heat ,,treatment4 ,heat slowly to a low red1 about #adjj degrees ,fahrenheit1 or if low carbon content to #aejj degrees ,fahrenheit2 being very careful not to over-heat4 ,quench in good clean tempered water2 keeping tool constantly in motion4 ,draw from #bej degrees ,fahrenheit to #djj degrees ,fahrenheit4 ,,typical ,,analysis ,,of ,,fast ,,finishing ,,semi-,,high ,,speed4 ,carbon #a4bh ,tungsten #c4ef ,phosphorus 4#jba ,sulphur 4#jai ,manganese 4#caf ,silicon 4#bga ,iron 7by deduction7 #id4ecc ,,uses4 ,do not confuse the ,high ,speed1 although excellent for turning chilled cast iron1 clean finishing cuts4 ,especially adapted for taps and reamers1 as well as for tools for brass1 bronze1 aluminum1 copper and chilled roll turning4 ,,heat ,,treatment4 ,heat slowly to full bright red1 #adbe degrees ,fahrenheit to #aejj degrees ,fahrenheit4 ,quench in luke warm water4 ,keep tool constantly in motion4 ,draw to not over #cjj degrees ,fahrenheit4 ,,typical ,,analysis ,,of ,,simple ,,carbon ,,tool ,,steel4 ,carbon #a4ab ,phosphorus 4#jji ,sulphur 4#jaa ,manganese 4#bed ,silicon 4#bac ,iron 7by deduction7 #ih4cic ,,uses4 ,general tool room usage with moderate cutting speeds4 ,excellent lathe1 planer1 and shaper tools1 drills1 shear blades 7for cold work only7 punches1 chisels1 files and mining tools4 ,,heat ,,treatment4 ,heat slowly to ,low ,red heat1 approximately #acge degrees ,fahrenheit 7the higher the carbon the lower the heat74 ,care not to over-heat4 ,quench in good clean luke warm water4 ,draw to not over #cej degrees ,fahrenheit4 ,,typical ,,analysis ,,of ,,non-,,shrinking ,,oil ,,hardening ,,steel4 ,carbon 4#ia ,phosphorus 4#jaf ,sulphur 4#jai ,manganese #a4fb ,silicon 4#ca ,iron 7by deduction7 #ig4abe ,,uses4 ,threading dies1 chasers1 taps1 reamers1 and all master tools4 ,for gauges1 plugs1 etc4 ,especially adapted for stamping1 punching1 trimming dies and many other uses where it is necessary to overcome shrinking1 warping or change of shape4 ,,heat ,,treatment4 ,heat very slowly to pre-heating temperature of #abjj degrees ,fahrenheit1 then to hardening temperature from #acfj degrees ,fahrenheit to #adbe degrees ,fahrenheit1 depending upon size of piece being treated4 ,harden in lard1 linseed or cottonseed oil2 preferably fish oil4 ,do not quench in water4 ,draw cutting tools1 taps and reamers at #bej degrees to #cjj degrees ,fahrenheit4 ,large tools such as blanking and stamping dies at #djj degrees to #dej degrees ,fahrenheit4 ,,typical ,,analysis ,,of ,,special ,,hot ,,work ,,alloy ,,steel4 ,carbon 4#hf ,chromium #c4ga ,phosphorus 4#jbc ,sulphur 4#jai ,manganese 4#cha ,silicon 4#bfg ,iron 7by deduction7 #id4gdj ,,uses4 ,an excellent composition for hot work in service for grippers1 headers1 hot punches1 hot shear blades and similar tools4 ,especially valuable in structural steel and boiler shop work4 ,rivet sets and bull dies made from a steel of this composition ought to resist breaking and battering4 ,,heat ,,treatment4 ,very flexible hardening in air1 oil or water4 ,if air is used heat to #afge degrees to #agej degrees ,fahrenheit and place under dry air blast1 or stand in cool place4 ,to harden in oil1 heat to #aejj degrees to #aeej degrees ,fahrenheit and quench in thin oil4 ,to harden in water1 heat to #adge degrees ,fahrenheit to #aebe degrees ,fahrenheit and quench in cool water4 ,draw from #bej degrees to #cjj degrees ,fahrenheit4