CHAPTER IV.HIGH SPEED STEELS.After the processes of hardening and drawing our sample of simple carbon tool steel have become thoroughly mastered, 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 tools. However, when the extraordinary demands of modern industry required faster and faster cutting speeds, and deeper and deeper cuts, we commenced to realize that our familiar carbon tool steels would not fill the bill. This was due to the fact that as the tools became pressed with the faster speeds and deeper cuts, 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 approached. 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 ruined.Therefore, 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 "High Speed" Steel.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 steel, except that as we begin to add various elements other than carbon to the melt, 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 undertaking.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 employed. 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 range. Of course, 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 hard. The effect which these elements appear to produce in the period of critical range can be seen from figure 7.Graph showing the complex behavior of high speed steel during heating and cooling over time and temperatureIn 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 Steel. The readings of the pyrometer were carefully recorded and when plotted on the graph sheet produced the picture under discussion.Here it will be noticed that the vivid reaction, which we might have expected would occur as the temperature indicating the first critical range was reached, was materially reduced. This might lead us to suspect that the desired allotropic change had not completely taken place at this point. In fact we noticed that the pyrometer needle did not record a vivid critical point until a very much higher temperature was reached. 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 Steel.In a later chapter of this little volume we define Carbon Steels as those which donotcontain enough of any element other than carbon to materially affect the physical properties which the steel will have when hard. High Speed Steels which are one of a very important group of special alloy steels, are those steels to which some elementotherthan carbon has been added in sufficient amount to materially effect the physical properties which the steel will have when hard.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 Tungsten. We will discuss the various effects which the different elements give to the different alloy steels in a later chapter, but for the present we will confine ourselves to a brief discussion of the heat treatment of the now famous modern High Speed Steel.High speed steel shows a granular fine structure in the magnified section of a hyper-eutectoid rod.High Speed Steel. Carbon .58%. Structure: Very fine pearlitic condition, with particles of free carbide. Mag. 500xAs previously suggested the pressing demand of modern industry for quicker work, greater efficiency and enormously increased out-put of product, gave rise to the necessity of producing far more remarkable tools than was possible with the old fashioned carbon tool steel. 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 and, which could be made sufficiently tough to stand the enormous cutting strains and chatter and vibration of the machine, 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 hot.After the seemingly impossible task of producing a steel to meet these terrific conditions had been successfully accomplished, the next question which arose was to produce a machine which was sufficiently powerful to stand the work done by the tool, and so fast has been the progress made by the tool steel producer, 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 Steel.Now, 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 Steel, we would find that many of the same phenomena previously noticed would again be recorded.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 oil. In fact, water would cause the High Speed Steel to cool off far too quickly so that it would be likely to crack and be rendered useless.A peculiar action of the various elements in High Speed Steel is very likely to materially retard the change of one allotropic form into another. In fact, the change is so slow that after a piece of High Speed Steel has been heated above the critical temperature, it will actually retain its hardened or austenitic condition even if allowed to cool in the air, and it would only be possible to get it back into its softened condition by the lengthy process of annealing.Annealing is the process of undoing exactly what the act of hardening accomplished. Long tubes are filled with the tool steel bars and sealed from the air and then placed into the annealing furnaces, wherein the annealing temperature is maintained for a sufficient number of hours, until the steel has had an opportunity to become thoroughly softened.As before stated "drawing" or "tempering" means the careful re-heating of the steel to 400 degrees Fahr. to 600 degrees Fahr., thus allowing a slight "slipping" of enough of the higher allotropic solution to a lower form, which it is always eager to accomplish at temperatures near the point of recalescence. This, of course, relieves the excess brittleness of the hardened steel.Annealing is the complete release of the higher allotropic form of the solution and the "trapped" carbon which allows of their return to the normal condition of pearlite and alpha iron. Therefore, it is necessary to heat the steel above the point of recalescence and cool more or less slowly. Different speeds of cooling give different grain, size, structure and physical property.This explanation of hardening, which is known as the "allotropic theory" is not universally accepted, although it is difficult to find a better or more complete explanation of the remarkable phenomena involved. However, 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 live.
CHAPTER IV.
HIGH SPEED STEELS.
After the processes of hardening and drawing our sample of simple carbon tool steel have become thoroughly mastered, 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 tools. However, when the extraordinary demands of modern industry required faster and faster cutting speeds, and deeper and deeper cuts, we commenced to realize that our familiar carbon tool steels would not fill the bill. This was due to the fact that as the tools became pressed with the faster speeds and deeper cuts, 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 approached. 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 ruined.
Therefore, 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 "High Speed" Steel.
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 steel, except that as we begin to add various elements other than carbon to the melt, 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 undertaking.
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 employed. 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 range. Of course, 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 hard. The effect which these elements appear to produce in the period of critical range can be seen from figure 7.
Graph showing the complex behavior of high speed steel during heating and cooling over time and temperature
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 Steel. The readings of the pyrometer were carefully recorded and when plotted on the graph sheet produced the picture under discussion.
Here it will be noticed that the vivid reaction, which we might have expected would occur as the temperature indicating the first critical range was reached, was materially reduced. This might lead us to suspect that the desired allotropic change had not completely taken place at this point. In fact we noticed that the pyrometer needle did not record a vivid critical point until a very much higher temperature was reached. 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 Steel.
In a later chapter of this little volume we define Carbon Steels as those which donotcontain enough of any element other than carbon to materially affect the physical properties which the steel will have when hard. High Speed Steels which are one of a very important group of special alloy steels, are those steels to which some elementotherthan carbon has been added in sufficient amount to materially effect the physical properties which the steel will have when hard.
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 Tungsten. We will discuss the various effects which the different elements give to the different alloy steels in a later chapter, but for the present we will confine ourselves to a brief discussion of the heat treatment of the now famous modern High Speed Steel.
High speed steel shows a granular fine structure in the magnified section of a hyper-eutectoid rod.
High Speed Steel. Carbon .58%. Structure: Very fine pearlitic condition, with particles of free carbide. Mag. 500x
As previously suggested the pressing demand of modern industry for quicker work, greater efficiency and enormously increased out-put of product, gave rise to the necessity of producing far more remarkable tools than was possible with the old fashioned carbon tool steel. 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 and, which could be made sufficiently tough to stand the enormous cutting strains and chatter and vibration of the machine, 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 hot.
After the seemingly impossible task of producing a steel to meet these terrific conditions had been successfully accomplished, the next question which arose was to produce a machine which was sufficiently powerful to stand the work done by the tool, and so fast has been the progress made by the tool steel producer, 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 Steel.
Now, 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 Steel, we would find that many of the same phenomena previously noticed would again be recorded.
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 oil. In fact, water would cause the High Speed Steel to cool off far too quickly so that it would be likely to crack and be rendered useless.
A peculiar action of the various elements in High Speed Steel is very likely to materially retard the change of one allotropic form into another. In fact, the change is so slow that after a piece of High Speed Steel has been heated above the critical temperature, it will actually retain its hardened or austenitic condition even if allowed to cool in the air, and it would only be possible to get it back into its softened condition by the lengthy process of annealing.
Annealing is the process of undoing exactly what the act of hardening accomplished. Long tubes are filled with the tool steel bars and sealed from the air and then placed into the annealing furnaces, wherein the annealing temperature is maintained for a sufficient number of hours, until the steel has had an opportunity to become thoroughly softened.
As before stated "drawing" or "tempering" means the careful re-heating of the steel to 400 degrees Fahr. to 600 degrees Fahr., thus allowing a slight "slipping" of enough of the higher allotropic solution to a lower form, which it is always eager to accomplish at temperatures near the point of recalescence. This, of course, relieves the excess brittleness of the hardened steel.
Annealing is the complete release of the higher allotropic form of the solution and the "trapped" carbon which allows of their return to the normal condition of pearlite and alpha iron. Therefore, it is necessary to heat the steel above the point of recalescence and cool more or less slowly. Different speeds of cooling give different grain, size, structure and physical property.
This explanation of hardening, which is known as the "allotropic theory" is not universally accepted, although it is difficult to find a better or more complete explanation of the remarkable phenomena involved. However, 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 live.
CHAPTER V.THE GENERAL EFFECT OF THE MOREIMPORTANT ELEMENTS IN TOOL STEELS.We know that all metals of engineering nature are crystalline in character, that is, the crystals form when the metal solidifies. If these crystals were free it would be easy to determine definitely just what properties the metal would have. However, the crystals are not free, but exist in the steel in combination with many other types of crystals. This results in many complicated and complex possibilities in the finished product, and will bring us presently to the subject of "Alloy Steels".CARBON STEELS.Carbon Steels are those which donotcontain enough of any elementotherthan carbon to materially affect the physical properties which the steel will have when hard. Carbon is one element used above all others by manufacturers in getting required physical properties. An increase of one hundredth of one per cent (.01%) gives a tensile strength of about one thousand pounds per square inch, but even this amount of carbon also regularly decreases the ductility of the finished product. When steel is heated red hot and plunged into water, the carbon in the metal unites with the iron in some peculiar way so that it produces a compound of extreme hardness. If the steel contains nine-tenths of one per cent (.90%) of carbon, a sharp point so quenched will almost scratch glass. With one per cent (1.00%) of carbon it reaches nearly its limit of hardness. Now carbon steels with this percentage carbon can be used for some of the harder tools, which do not require much ductility or toughness, but with higher carbon contents than this percentage, the brittleness increases so fast that the usefulness of the metal is decidedly limited.Therefore, when the steel must meet requirements other than just that of hardness, such as, strength, ductility, toughness, resistance to repeated shock, "red hardness", etc., then it is necessary to resort to other means and combinations for obtaining the required needs. It is to be remembered that such methods and combinations will materially increase the cost of the final product.ALLOY STEELS.What is an alloy steel? The general definition of an alloy steel is, "a solidified solution of two or more metallic substances". The International Committee upon the nomenclature of iron and steel defines alloy steels as "those steels which owe their properties chiefly to the presence of an element (or elements)otherthan carbon".This latter definition more nearly applies to our case, but it must be born in mind that the distinction between an element added merely to produce a slight benefit to ordinary carbon steel, and the very same element added to produce an alloy steel itself, is sometimes a very delicate one. For example: Manganese is added in amounts usually less than 1.50% to all Bessemer and Open-Hearth Steels, for the purpose of getting rid of oxygen, and neutralizing the effect of the sulphur. But this does not produce an Alloy Steel. When we make "manganese steel" containing 10 to 20% manganese, the material then has properties quite different from the same steel without the manganese, and we then have a Manganese Alloy Steel.Thus, for our purpose, we may consider an alloy steel as being one to which some elementotherthan carbon has been added in sufficient amount to materially affect the physical properties which the steel will have when hard.HIGH SPEED STEELS.High Speed Steels are perhaps the most important of alloy steels, 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 speed. This, of course, subjects the tool to severe operating conditions, which simple carbon steels could not stand. These steels have other notable characteristics, among which is that of "self-hardening" or "air-hardening", as it is sometimes called. This means, when the steel cools naturally in the air, from a red heat or above, it is not soft like ordinary steel, but is hard and capable of cutting other metals.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 steel. Because of this property, 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 tools. 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 hardest, and the chip may, itself, by its friction on the tool, and the internal work done on it, by upsetting it, be heated to a blue heat, or even hotter.ELEMENTS WHICH OCCUR IN ALL STEELS.There are certain elements which are practically always found inanykind of steel. These elements are capable of producing many varied effects on the finished product. They are Iron, Carbon, Manganese, Silicon, Phosphorous and Sulphur.IRON.The base of all steels is Iron. It goes without saying that this element should be obtained in the best and purest state possible. Probably the best "base" iron comes largely from Sweden, which country seems to have produced the highest quality of iron on the market today.CARBON.Carbon has already been discussed under Carbon Steels, although, of course, its importance in Alloy Steels must not be under-estimated. The proportion of carbon aimed at in high speed tool steels is about 0.65%, which in simple steel would not be enough to give the maximum hardness, even if the steel were heated above the critical point and quenched in water, and still less so when the steel is cooled as slowly as these steels are in their treatment. This shows that the carbon element acts in a different way from what it does in simple carbon steels as previously discussed.MANGANESE.Manganese Steel is a typical self-hardening steel and so, obviously, is any steel which is in the austenitic condition at atmospheric temperatures, that is to say, whose critical temperature is below atmospheric temperature. Thus, self-hardening steels are non-magnetic. Because of its low-yield point, manganese steel does not give satisfaction in many lines, for which otherwise it might be eminently fitted.Manganese used insmallquantities (.30% to 1.50%) will produce certain desired effects. Under these conditions it acts as a purifier. 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 manganese. There is also good reason for believing that manganese prevents the coarse crystallization, which impurities such as Phosphorus and Sulphur would otherwise produce. Five per cent to 14% manganese renders the steel non-magnetic as well as a poor conductor of electricity.SILICON.The dividing line between silicon-treated steels and silicon-alloy steels is not clearly defined, but the latter are used for several important purposes.Such steel has been used in springs of the leaf type for automobiles and other vehicles, the silicon being considered to add slightly to the toughness of the springs. However, the most important use of steels of this type is probably in the manufacture of electrical machinery. It is possible to produce a silicon-alloy steel which has not only a greater magnetic permeability than the purest iron, but also, a high electrical resistance. Its hysteresis is, of course, low, this property always accompanying a high permeability. It therefore is a very valuable material for use in electro-magnets, and in electric generating machinery, is the most efficient material known.In silicon-treated steels, the silicon is used somewhat as a scavenger, although it also produces results somewhat similar to manganese.PHOSPHORUS.Phosphorus has little effect upon the hot properties, 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 carbon.SULPHUR.Sulphur has just the opposite effect of Phosphorus, and makes the steel crack while it is being hot worked, although after the metal is cold it seems to have no particular effect upon the physical properties.ELEMENTS WHICH HAVE BECOME ESPECIALLY ASSOCIATED WITH SPECIAL ALLOY STEELS.Such elements are:—Chromium, Tungsten, Molybdenum, Vanadium, Cobalt, Uranium, Titanium, Aluminum, etc.CHROMIUM.Chromium is an indispensable constituent in modern high speed steel, and does not make a poor high speed steel, even when used alone. The chief effect which chromium produces in high speed steels is undoubtedly that of "hardening". However, chromium, like carbon, will produce brittleness, if added in too large quantities, although if kept down to between 2 to 5% it seems to allow the lowering of the carbon element, while at the same time maintaining the desired hardening effect, without causing undue brittleness. The great hardness in the face of an armor plate, and the great toughness in the back of the plate, also the superb properties in the projectile which attempts to pierce the plate, can all be induced in chromium steels to a degree unattainable by the use of any other single element.As a simple chromium steel the product may be used in five-ply plates for the manufacture of safes. These plates are made of five alternate layers, two of chrome steel and three of soft steel, and after having been hardened, offer resistance to the drilling tools employed by burglars. Hardened chromium rolls are manufactured for use in cold-rolling metals. Files, ball and roller-bearings are other noted products of this type of steel. It is the essential constituent of those steels which neither rust nor tarnish.TUNGSTEN.It was soon found that the composition of "self-hardening" steels was not the best one for high speed steels. Tungsten was discovered as an element which gave the steel properties of hardness and toughness at a red heat. After the peculiar heat treatment had been learned, and the presence of manganese or chromium in addition to the tungsten was shown to be unnecessary in appreciable amounts, it was found that more durable qualities could be obtained by increasing the percentage of tungsten, while at the same time the carbon element was greatly reduced.The best grade of High Speed Steel ought to have a tungsten content of about 18.00% and a carbon content of about 0.65%. Thus whenever a steel is needed which must operate under especially severe conditions, this would be the steel to use. Such conditions are usually met in the case of rapid turning, boring, planing, slotting and shaping tools, also with twist drills and all forms of milling cutters, gear cutters, taps, reamers, special dies, etc.MOLYBDENUM.Molybdenum was once thought of as being somewhat in a class with tungsten, but its use in high speed tool steels is being generally discontinued. The reason for this is that it was found that in rapid steels this element caused irregular performance, such as large variations in the cutting speeds which they would stand. This element is also likely to make the steels seamy and contain physical imperfections. Molybdenum steels were also found to crack on quenching, and possess decided variations in internal structure.VANADIUM.Vanadium steels are still in their infancy. Therefore, the true value of this element in rapid steels must probably be held as not yet fully determined. With the single exception of carbon, no element has such a powerful effect upon steel as vanadium, for it is only necessary to use from 0.10 to 0.15% in order to obtain very noticeable results. In addition to acting as a very great strengthener of steel, especially against dynamic strains, vanadium also serves as a scavenger in getting rid of oxygen and possibly nitrogen. It is also said to decrease segregation, which we may readily believe, as most of the elements which quiet the steel have this effect."Vanadium Steels" demand a somewhat higher price than do those steels which do not contain this element in appreciable amounts. It is, of course, especially useful for all purposes where strength and lightness are desired, such as springs, axles, frames and other parts of railroad rolling stock, and automobiles.COBALT.The valuable effect of cobalt is claimed to be that it increases the red hardness of high speed tool steel, enabling the steel to cut at a higher speed. However, this element much resembles nickel, which has been largely condemned as not being a desirable ingredient for high speed tool steels, because it has the effect of making the edge of the finished tool soft or "leady".URANIUM, TITANIUM AND ALUMINUM.These elements are generally classed as scavengers, although recently important claims have been advanced for their effect upon the physical properties of steel. This is especially true for the first two. In present practice, however, they are used almost entirely as deoxidizers or cleansers, and are added to the metal for this purpose only.IMPURITIES.Phosphorus, Sulphur and Copper are the most noted impurities which occur in steel. The first two are practically always present in greater or smaller amounts as the case may be. The best processes of tool steel manufacture are capable of producing steels with no copper. While Aluminum is not generally classed as an impurity, it nevertheless sometimes shows up in the finished product when its presence is not desired, and therefore, might be considered an impurity.Combinations of iron with some or all of the above elements in the form of slags and oxides are other well known impurities.From the forgoing pages it must be evident that producing a steel with exactly the correct chemical content is onlyonestep towards securing a satisfactory product. However, it might be well if we were to briefly sum up a few of the more important features of our discussion on this interesting subject.HEAT TREATMENT.The heat treatment of tool steels is of the utmost importance. 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 so. Today, however, progressive manufacturers are using the results of research and such thorough scientific investigation that the process has become far more complicated and complex, and the results obtained are correspondingly more remarkable.Chemically perfect steel may be easily and completely ruined during the process of melting, cogging, rolling, hammering, annealing, heat treating and tempering. It is the business of the steel manufacturer to carefully guard his product up through the process of annealing, but it usually falls to the tool maker to undertake the delicate operations of heat treatment and tempering.HARDENING.The application of heat alone to steel can very materially affect the condition of the structure of the metal, either with or without simultaneous mechanical treatment. Depending upon the degree of heat, the rate of heating and cooling and the duration of such treatment, this application may be decidedly beneficial or harmful as the case may be.We now know that when steel is heated above the critical point, and is then allowed to rapidly cool, a very marked hardness in the metal is produced. The degree of hardness so attained will, in general, vary directly with (1) the percentage of carbon, (2) the rate of cooling, (3) and the temperature above the critical point from which the cooling takes place. When the steel comes from the rolling mill and from the finishing hammers it is in this hardened condition. Therefore, in order to render it soft and ductile enough to cut and work up into certain desired shapes, sizes and tools, it is necessary to subject the steel to the process of annealing. This operation is usually undertaken by the steel producer, under which circumstances he is able to control his product through this delicate procedure, and deliver the same to his customers in the best possible condition for their use.ANNEALING.Annealing has for its object: (1) Completely undoing the effect of hardening, leaving the steel soft and ductile (2) refining the grain, in which case the crystals are allowed to re-arrange and re-adjust themselves, usually growing to a rather large size (3) and removing strains and stresses caused by too rapid cooling. Such cooling strains are particularly likely to exist where the rate of cooling is different in different parts of the bar, but the process of annealing ought to remedy any such condition, leaving the steel soft, ductile and of refined and uniform crystalline structure throughout.The process of annealing is easier to explain than it is to actually put into practice. The steel is first packed in lime, charcoal, fine dry ashes or sand, and then sealed in long air-tight tubes or boxes.The whole receptacle is next slowly brought up to a dull red heat, of about 1500 degrees Fahrenheit.It is very important to heat the material uniformly all the way through, and then hold it in this condition from three to eight hours. Thus, allowing the slipping of one allotropic condition into another.The receptacle must be cooled equally slowly, either allowing the packed steel to cool slowly down with the furnace, or by placing the same in a soaking or cooling pit, which also accomplishes the desired result.After the receptacle has become entirely cooled it is opened and the steel unpacked and removed. The steel is then ready for its final inspection before shipping to the tool maker.TEMPERING.The process of tempering usually has to be undertaken by the tool maker or user after the annealed steel, which he received from the steel mill, has been cut up and shaped into the desired form and size.The main object of tempering steel is to re-harden the material to such an extent that it will cut other metals, retaining its desired shape size and cutting edge, while at the same time it must not possess too much brittleness. The treatment varies materially with different brands of steels.For the average grade of the best High Speed Steel containing from 16% to 18% tungsten, the tool should be brought very slowly up to a dull cherry red. 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-heater, in order that the heating might be effected just as slowly as possible. The pre-heating operation should bring the tool up to about 1600 to 1800 degrees Fahrenheit, after which the tool should be placed in the high heating furnace and brought up to 2300 to 2400 degrees Fahrenheit, or a white sweating heat. Care should be taken not to allow the tool to remain in this condition for more than an instant, as it is then in a very critical condition and could be easily burned or ruined.Therefore, the tool should be immediately pulled from the furnace and plunged into a good clean oil bath, keeping it constantly in motion.As High Speed Steels are air-hardening steels, it is also the practice to harden these steels by simply placing the cutting edge in an air blast, which produces maximum hardness in the desired point and allows the body of the tool to cool at a little slower rate, thus slightly relieving the cooling strains and producing a little less brittleness therein. Such cooling strains can be relieved throughout the whole tool by drawing the same back to about 400 to 500 degrees Fahrenheit, and sometimes as high as 1050 degrees Fahrenheit, depending upon the particular tool and its use.The treatment of Carbon Steels varies with each particular brand. Great care must always be taken to heat the steel uniformly, as a material which is heated unevenly will expand and contract unevenly and, in consequence, will crack when quenched.The steel should always be hardened on the rising heat, in general bringing the same slowly up to a dull cherry red, or to about 1450 degrees Fahrenheit, and then quenching in clear cold water, keeping the same in motion until the steel is cold. The temper should then be drawn according to the purpose of the tool, which could only be discussed for each particular case. The following range of temperatures are interesting, as being approximately indicated by the thin film of oxide tints which occur on the tool undergoing a tempering operation:Pale Yellow428 Degrees FahrenheitGolden Yellow469 Degrees FahrenheitPurple531 Degrees FahrenheitBright Blue550 Degrees FahrenheitDark Blue601 Degrees FahrenheitCONCLUSION.The effects of annealing, rolling, hammering, treating and tempering are best understood by those manufacturers who make a specialty of supplying a high grade tool steel, and in general it would be well if customers would consult freely with the producers of these steels, before attempting the delicate undertaking of Heat Treatment.
CHAPTER V.
THE GENERAL EFFECT OF THE MOREIMPORTANT ELEMENTS IN TOOL STEELS.
We know that all metals of engineering nature are crystalline in character, that is, the crystals form when the metal solidifies. If these crystals were free it would be easy to determine definitely just what properties the metal would have. However, the crystals are not free, but exist in the steel in combination with many other types of crystals. This results in many complicated and complex possibilities in the finished product, and will bring us presently to the subject of "Alloy Steels".
CARBON STEELS.
Carbon Steels are those which donotcontain enough of any elementotherthan carbon to materially affect the physical properties which the steel will have when hard. Carbon is one element used above all others by manufacturers in getting required physical properties. An increase of one hundredth of one per cent (.01%) gives a tensile strength of about one thousand pounds per square inch, but even this amount of carbon also regularly decreases the ductility of the finished product. When steel is heated red hot and plunged into water, the carbon in the metal unites with the iron in some peculiar way so that it produces a compound of extreme hardness. If the steel contains nine-tenths of one per cent (.90%) of carbon, a sharp point so quenched will almost scratch glass. With one per cent (1.00%) of carbon it reaches nearly its limit of hardness. Now carbon steels with this percentage carbon can be used for some of the harder tools, which do not require much ductility or toughness, but with higher carbon contents than this percentage, the brittleness increases so fast that the usefulness of the metal is decidedly limited.
Therefore, when the steel must meet requirements other than just that of hardness, such as, strength, ductility, toughness, resistance to repeated shock, "red hardness", etc., then it is necessary to resort to other means and combinations for obtaining the required needs. It is to be remembered that such methods and combinations will materially increase the cost of the final product.
ALLOY STEELS.
What is an alloy steel? The general definition of an alloy steel is, "a solidified solution of two or more metallic substances". The International Committee upon the nomenclature of iron and steel defines alloy steels as "those steels which owe their properties chiefly to the presence of an element (or elements)otherthan carbon".
This latter definition more nearly applies to our case, but it must be born in mind that the distinction between an element added merely to produce a slight benefit to ordinary carbon steel, and the very same element added to produce an alloy steel itself, is sometimes a very delicate one. For example: Manganese is added in amounts usually less than 1.50% to all Bessemer and Open-Hearth Steels, for the purpose of getting rid of oxygen, and neutralizing the effect of the sulphur. But this does not produce an Alloy Steel. When we make "manganese steel" containing 10 to 20% manganese, the material then has properties quite different from the same steel without the manganese, and we then have a Manganese Alloy Steel.
Thus, for our purpose, we may consider an alloy steel as being one to which some elementotherthan carbon has been added in sufficient amount to materially affect the physical properties which the steel will have when hard.
HIGH SPEED STEELS.
High Speed Steels are perhaps the most important of alloy steels, 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 speed. This, of course, subjects the tool to severe operating conditions, which simple carbon steels could not stand. These steels have other notable characteristics, among which is that of "self-hardening" or "air-hardening", as it is sometimes called. This means, when the steel cools naturally in the air, from a red heat or above, it is not soft like ordinary steel, but is hard and capable of cutting other metals.
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 steel. Because of this property, 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 tools. 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 hardest, and the chip may, itself, by its friction on the tool, and the internal work done on it, by upsetting it, be heated to a blue heat, or even hotter.
ELEMENTS WHICH OCCUR IN ALL STEELS.
There are certain elements which are practically always found inanykind of steel. These elements are capable of producing many varied effects on the finished product. They are Iron, Carbon, Manganese, Silicon, Phosphorous and Sulphur.
IRON.
The base of all steels is Iron. It goes without saying that this element should be obtained in the best and purest state possible. Probably the best "base" iron comes largely from Sweden, which country seems to have produced the highest quality of iron on the market today.
CARBON.
Carbon has already been discussed under Carbon Steels, although, of course, its importance in Alloy Steels must not be under-estimated. The proportion of carbon aimed at in high speed tool steels is about 0.65%, which in simple steel would not be enough to give the maximum hardness, even if the steel were heated above the critical point and quenched in water, and still less so when the steel is cooled as slowly as these steels are in their treatment. This shows that the carbon element acts in a different way from what it does in simple carbon steels as previously discussed.
MANGANESE.
Manganese Steel is a typical self-hardening steel and so, obviously, is any steel which is in the austenitic condition at atmospheric temperatures, that is to say, whose critical temperature is below atmospheric temperature. Thus, self-hardening steels are non-magnetic. Because of its low-yield point, manganese steel does not give satisfaction in many lines, for which otherwise it might be eminently fitted.
Manganese used insmallquantities (.30% to 1.50%) will produce certain desired effects. Under these conditions it acts as a purifier. 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 manganese. There is also good reason for believing that manganese prevents the coarse crystallization, which impurities such as Phosphorus and Sulphur would otherwise produce. Five per cent to 14% manganese renders the steel non-magnetic as well as a poor conductor of electricity.
SILICON.
The dividing line between silicon-treated steels and silicon-alloy steels is not clearly defined, but the latter are used for several important purposes.
Such steel has been used in springs of the leaf type for automobiles and other vehicles, the silicon being considered to add slightly to the toughness of the springs. However, the most important use of steels of this type is probably in the manufacture of electrical machinery. It is possible to produce a silicon-alloy steel which has not only a greater magnetic permeability than the purest iron, but also, a high electrical resistance. Its hysteresis is, of course, low, this property always accompanying a high permeability. It therefore is a very valuable material for use in electro-magnets, and in electric generating machinery, is the most efficient material known.
In silicon-treated steels, the silicon is used somewhat as a scavenger, although it also produces results somewhat similar to manganese.
PHOSPHORUS.
Phosphorus has little effect upon the hot properties, 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 carbon.
SULPHUR.
Sulphur has just the opposite effect of Phosphorus, and makes the steel crack while it is being hot worked, although after the metal is cold it seems to have no particular effect upon the physical properties.
ELEMENTS WHICH HAVE BECOME ESPECIALLY ASSOCIATED WITH SPECIAL ALLOY STEELS.
Such elements are:—Chromium, Tungsten, Molybdenum, Vanadium, Cobalt, Uranium, Titanium, Aluminum, etc.
CHROMIUM.
Chromium is an indispensable constituent in modern high speed steel, and does not make a poor high speed steel, even when used alone. The chief effect which chromium produces in high speed steels is undoubtedly that of "hardening". However, chromium, like carbon, will produce brittleness, if added in too large quantities, although if kept down to between 2 to 5% it seems to allow the lowering of the carbon element, while at the same time maintaining the desired hardening effect, without causing undue brittleness. The great hardness in the face of an armor plate, and the great toughness in the back of the plate, also the superb properties in the projectile which attempts to pierce the plate, can all be induced in chromium steels to a degree unattainable by the use of any other single element.
As a simple chromium steel the product may be used in five-ply plates for the manufacture of safes. These plates are made of five alternate layers, two of chrome steel and three of soft steel, and after having been hardened, offer resistance to the drilling tools employed by burglars. Hardened chromium rolls are manufactured for use in cold-rolling metals. Files, ball and roller-bearings are other noted products of this type of steel. It is the essential constituent of those steels which neither rust nor tarnish.
TUNGSTEN.
It was soon found that the composition of "self-hardening" steels was not the best one for high speed steels. Tungsten was discovered as an element which gave the steel properties of hardness and toughness at a red heat. After the peculiar heat treatment had been learned, and the presence of manganese or chromium in addition to the tungsten was shown to be unnecessary in appreciable amounts, it was found that more durable qualities could be obtained by increasing the percentage of tungsten, while at the same time the carbon element was greatly reduced.
The best grade of High Speed Steel ought to have a tungsten content of about 18.00% and a carbon content of about 0.65%. Thus whenever a steel is needed which must operate under especially severe conditions, this would be the steel to use. Such conditions are usually met in the case of rapid turning, boring, planing, slotting and shaping tools, also with twist drills and all forms of milling cutters, gear cutters, taps, reamers, special dies, etc.
MOLYBDENUM.
Molybdenum was once thought of as being somewhat in a class with tungsten, but its use in high speed tool steels is being generally discontinued. The reason for this is that it was found that in rapid steels this element caused irregular performance, such as large variations in the cutting speeds which they would stand. This element is also likely to make the steels seamy and contain physical imperfections. Molybdenum steels were also found to crack on quenching, and possess decided variations in internal structure.
VANADIUM.
Vanadium steels are still in their infancy. Therefore, the true value of this element in rapid steels must probably be held as not yet fully determined. With the single exception of carbon, no element has such a powerful effect upon steel as vanadium, for it is only necessary to use from 0.10 to 0.15% in order to obtain very noticeable results. In addition to acting as a very great strengthener of steel, especially against dynamic strains, vanadium also serves as a scavenger in getting rid of oxygen and possibly nitrogen. It is also said to decrease segregation, which we may readily believe, as most of the elements which quiet the steel have this effect.
"Vanadium Steels" demand a somewhat higher price than do those steels which do not contain this element in appreciable amounts. It is, of course, especially useful for all purposes where strength and lightness are desired, such as springs, axles, frames and other parts of railroad rolling stock, and automobiles.
COBALT.
The valuable effect of cobalt is claimed to be that it increases the red hardness of high speed tool steel, enabling the steel to cut at a higher speed. However, this element much resembles nickel, which has been largely condemned as not being a desirable ingredient for high speed tool steels, because it has the effect of making the edge of the finished tool soft or "leady".
URANIUM, TITANIUM AND ALUMINUM.
These elements are generally classed as scavengers, although recently important claims have been advanced for their effect upon the physical properties of steel. This is especially true for the first two. In present practice, however, they are used almost entirely as deoxidizers or cleansers, and are added to the metal for this purpose only.
IMPURITIES.
Phosphorus, Sulphur and Copper are the most noted impurities which occur in steel. The first two are practically always present in greater or smaller amounts as the case may be. The best processes of tool steel manufacture are capable of producing steels with no copper. While Aluminum is not generally classed as an impurity, it nevertheless sometimes shows up in the finished product when its presence is not desired, and therefore, might be considered an impurity.
Combinations of iron with some or all of the above elements in the form of slags and oxides are other well known impurities.
From the forgoing pages it must be evident that producing a steel with exactly the correct chemical content is onlyonestep towards securing a satisfactory product. However, it might be well if we were to briefly sum up a few of the more important features of our discussion on this interesting subject.
HEAT TREATMENT.
The heat treatment of tool steels is of the utmost importance. 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 so. Today, however, progressive manufacturers are using the results of research and such thorough scientific investigation that the process has become far more complicated and complex, and the results obtained are correspondingly more remarkable.
Chemically perfect steel may be easily and completely ruined during the process of melting, cogging, rolling, hammering, annealing, heat treating and tempering. It is the business of the steel manufacturer to carefully guard his product up through the process of annealing, but it usually falls to the tool maker to undertake the delicate operations of heat treatment and tempering.
HARDENING.
The application of heat alone to steel can very materially affect the condition of the structure of the metal, either with or without simultaneous mechanical treatment. Depending upon the degree of heat, the rate of heating and cooling and the duration of such treatment, this application may be decidedly beneficial or harmful as the case may be.
We now know that when steel is heated above the critical point, and is then allowed to rapidly cool, a very marked hardness in the metal is produced. The degree of hardness so attained will, in general, vary directly with (1) the percentage of carbon, (2) the rate of cooling, (3) and the temperature above the critical point from which the cooling takes place. When the steel comes from the rolling mill and from the finishing hammers it is in this hardened condition. Therefore, in order to render it soft and ductile enough to cut and work up into certain desired shapes, sizes and tools, it is necessary to subject the steel to the process of annealing. This operation is usually undertaken by the steel producer, under which circumstances he is able to control his product through this delicate procedure, and deliver the same to his customers in the best possible condition for their use.
ANNEALING.
Annealing has for its object: (1) Completely undoing the effect of hardening, leaving the steel soft and ductile (2) refining the grain, in which case the crystals are allowed to re-arrange and re-adjust themselves, usually growing to a rather large size (3) and removing strains and stresses caused by too rapid cooling. Such cooling strains are particularly likely to exist where the rate of cooling is different in different parts of the bar, but the process of annealing ought to remedy any such condition, leaving the steel soft, ductile and of refined and uniform crystalline structure throughout.
The process of annealing is easier to explain than it is to actually put into practice. The steel is first packed in lime, charcoal, fine dry ashes or sand, and then sealed in long air-tight tubes or boxes.
The whole receptacle is next slowly brought up to a dull red heat, of about 1500 degrees Fahrenheit.
It is very important to heat the material uniformly all the way through, and then hold it in this condition from three to eight hours. Thus, allowing the slipping of one allotropic condition into another.
The receptacle must be cooled equally slowly, either allowing the packed steel to cool slowly down with the furnace, or by placing the same in a soaking or cooling pit, which also accomplishes the desired result.
After the receptacle has become entirely cooled it is opened and the steel unpacked and removed. The steel is then ready for its final inspection before shipping to the tool maker.
TEMPERING.
The process of tempering usually has to be undertaken by the tool maker or user after the annealed steel, which he received from the steel mill, has been cut up and shaped into the desired form and size.
The main object of tempering steel is to re-harden the material to such an extent that it will cut other metals, retaining its desired shape size and cutting edge, while at the same time it must not possess too much brittleness. The treatment varies materially with different brands of steels.
For the average grade of the best High Speed Steel containing from 16% to 18% tungsten, the tool should be brought very slowly up to a dull cherry red. 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-heater, in order that the heating might be effected just as slowly as possible. The pre-heating operation should bring the tool up to about 1600 to 1800 degrees Fahrenheit, after which the tool should be placed in the high heating furnace and brought up to 2300 to 2400 degrees Fahrenheit, or a white sweating heat. Care should be taken not to allow the tool to remain in this condition for more than an instant, as it is then in a very critical condition and could be easily burned or ruined.
Therefore, the tool should be immediately pulled from the furnace and plunged into a good clean oil bath, keeping it constantly in motion.
As High Speed Steels are air-hardening steels, it is also the practice to harden these steels by simply placing the cutting edge in an air blast, which produces maximum hardness in the desired point and allows the body of the tool to cool at a little slower rate, thus slightly relieving the cooling strains and producing a little less brittleness therein. Such cooling strains can be relieved throughout the whole tool by drawing the same back to about 400 to 500 degrees Fahrenheit, and sometimes as high as 1050 degrees Fahrenheit, depending upon the particular tool and its use.
The treatment of Carbon Steels varies with each particular brand. Great care must always be taken to heat the steel uniformly, as a material which is heated unevenly will expand and contract unevenly and, in consequence, will crack when quenched.
The steel should always be hardened on the rising heat, in general bringing the same slowly up to a dull cherry red, or to about 1450 degrees Fahrenheit, and then quenching in clear cold water, keeping the same in motion until the steel is cold. The temper should then be drawn according to the purpose of the tool, which could only be discussed for each particular case. The following range of temperatures are interesting, as being approximately indicated by the thin film of oxide tints which occur on the tool undergoing a tempering operation:
CONCLUSION.
The effects of annealing, rolling, hammering, treating and tempering are best understood by those manufacturers who make a specialty of supplying a high grade tool steel, and in general it would be well if customers would consult freely with the producers of these steels, before attempting the delicate undertaking of Heat Treatment.
CHAPTER VI.WHAT TOOL STEEL IS DOING TOWARDS WINNING THE WAR.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 hearts.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 product. Of course, 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 cease. Volumes could be written on the vital importance of tools to industry in general, from the drills which drill out the hole in a hypodermic needle, to a twelve-ton drop-forge steam hammer. 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 war.We are told that we need ships, yet the ship industry could not proceed a day if its supply of necessary tools was cut off. 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 explained, 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 tools.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 torpedo, 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 attention.The metals which are destined to play an active part in actual warfare are naturally required to meet the most severe conditions imaginable. Thus we find the high manganese armor plate and the high chrome-manganese armor piercing projectile. We find the new specifications for steel forging, for hulls and engines now have rigid chrome-vanadium and special nickle requirements, all of which means that the tools that do the machining, planing, shaping, cutting, drilling, boring, reaming, stamping and many other operations must be made of a tougher and harder material than ever before.We know that for every man who may fight on the battle field, at least two men must labor in our shops and factories over mechanical operations.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 preparedness, 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 need. We realize that after all these months of increased industrial preparedness, we are, therefore, still unprepared in the full meaning of the word. The very foundation of our structure shows a startling amount of unpreparedness. We like to gaze upon the exterior towers and battlements of a castle of preparedness, 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 foundation, which threaten the stability of the entire mass. It is, therefore, some of these fundamental details which have been neglected as we have beheld the vision of the super-structure above. Pershing needs, 1,500,000 boys in khaki and over the shoulder of each is his protection against the Hun. Everyone of these rifles is a splendid monument of the accomplishment of tool steel and special alloy steel.Every day of our present existence it happens that over a million shells scream over the miles of battle line in France. This curtain of high explosive and shrapnel is another direct expression of the wonders which the modern high speed and special alloy steel have accomplished. We are told that a 3" shrapnel shell contains seventy drilled holes or a drilling of 19¼" in depth. That means that 1,600,000 feet or over three hundred miles of drilled holes are shot away every twenty-four hours on the battle fronts of Europe.In a publication "Fighting Industry" published by one of our largest twist drill companies in this country, we note that the drilled holes in various implements of our militant harness are as follows:8" shrapnel shell70Springfield rifle94Torpedo3466Machine gun350Aeroplane40893-ton auto truck5946Light ambulance15003" field gun1280Gun caisson594Anti-air craft gun1200Self-binder500Thresher420Motorcycle1160Four million men must work with tools in order that two million men may fight in France. These men can not, "just be given a tool and told to use it." 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 hands. At present every tool steel mill in America is straining its furnaces, hammers and rolling mills to their maximum capacity. They are working days, nights and Sundays and still the demand is far in excess of the supply. Conservative estimations show that with all the added machinery and equipment which is in the process of construction at this time, 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 product.As we gaze with belated pride upon the huge structure of our present Preparedness, 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 strain? We are at last forced to realize that tool steel is the very essence of our whole existence.Of course, the great importance of tool steel in this national emergency does not stop with the actual weapons of warfare. Besides the railroads, automobiles, tramways, elevators, bridges, buildings, shoes, clothing and in fact, every branch of the intricate mass of manufactured products so vital to our daily existence, nations are crying for bread. Victory hangs on our food supply. Our threshing machines, our reapers and our harvesting machinery are all working over time. 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 humanity, 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 give.
CHAPTER VI.
WHAT TOOL STEEL IS DOING TOWARDS WINNING THE WAR.
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 hearts.
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 product. Of course, 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 cease. Volumes could be written on the vital importance of tools to industry in general, from the drills which drill out the hole in a hypodermic needle, to a twelve-ton drop-forge steam hammer. 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 war.
We are told that we need ships, yet the ship industry could not proceed a day if its supply of necessary tools was cut off. 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 explained, 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 tools.
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 torpedo, 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 attention.
The metals which are destined to play an active part in actual warfare are naturally required to meet the most severe conditions imaginable. Thus we find the high manganese armor plate and the high chrome-manganese armor piercing projectile. We find the new specifications for steel forging, for hulls and engines now have rigid chrome-vanadium and special nickle requirements, all of which means that the tools that do the machining, planing, shaping, cutting, drilling, boring, reaming, stamping and many other operations must be made of a tougher and harder material than ever before.
We know that for every man who may fight on the battle field, at least two men must labor in our shops and factories over mechanical operations.
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 preparedness, 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 need. We realize that after all these months of increased industrial preparedness, we are, therefore, still unprepared in the full meaning of the word. The very foundation of our structure shows a startling amount of unpreparedness. We like to gaze upon the exterior towers and battlements of a castle of preparedness, 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 foundation, which threaten the stability of the entire mass. It is, therefore, some of these fundamental details which have been neglected as we have beheld the vision of the super-structure above. Pershing needs, 1,500,000 boys in khaki and over the shoulder of each is his protection against the Hun. Everyone of these rifles is a splendid monument of the accomplishment of tool steel and special alloy steel.
Every day of our present existence it happens that over a million shells scream over the miles of battle line in France. This curtain of high explosive and shrapnel is another direct expression of the wonders which the modern high speed and special alloy steel have accomplished. We are told that a 3" shrapnel shell contains seventy drilled holes or a drilling of 19¼" in depth. That means that 1,600,000 feet or over three hundred miles of drilled holes are shot away every twenty-four hours on the battle fronts of Europe.
In a publication "Fighting Industry" published by one of our largest twist drill companies in this country, we note that the drilled holes in various implements of our militant harness are as follows:
Four million men must work with tools in order that two million men may fight in France. These men can not, "just be given a tool and told to use it." 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 hands. At present every tool steel mill in America is straining its furnaces, hammers and rolling mills to their maximum capacity. They are working days, nights and Sundays and still the demand is far in excess of the supply. Conservative estimations show that with all the added machinery and equipment which is in the process of construction at this time, 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 product.
As we gaze with belated pride upon the huge structure of our present Preparedness, 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 strain? We are at last forced to realize that tool steel is the very essence of our whole existence.
Of course, the great importance of tool steel in this national emergency does not stop with the actual weapons of warfare. Besides the railroads, automobiles, tramways, elevators, bridges, buildings, shoes, clothing and in fact, every branch of the intricate mass of manufactured products so vital to our daily existence, nations are crying for bread. Victory hangs on our food supply. Our threshing machines, our reapers and our harvesting machinery are all working over time. 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 humanity, 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 give.