Metal bended folded & made into Discussions - Traveling within the World2024-03-29T01:13:00Zhttp://travelingwithintheworld.ning.com/group/metalbendedfoldedandmadeinto/forum?feed=yes&xn_auth=noForging, once and for all! by Kevin R. Cashen, www.cashenblades.comtag:travelingwithintheworld.ning.com,2012-09-01:2185477:Topic:1809232012-09-01T16:47:17.202ZDept of PMM Hall of Steelhttp://travelingwithintheworld.ning.com/profile/HallofSteel
<h2>The �lowdown� on smithing</h2>
<hr size="5"></hr><p>Anybody with more than a passing interest in knives has certainly encountered the tired old controversy of forging versus stock removal. Although I am a forge guy myself, I have often admired the restraint my grinding brothers have shown while being told how inferior their product was because they hadn�t hammered on the steel. This is particularly ironic when one considers the amount of things that can go wrong in the process of forging,…</p>
<h2>The �lowdown� on smithing</h2>
<hr size="5"/><p>Anybody with more than a passing interest in knives has certainly encountered the tired old controversy of forging versus stock removal. Although I am a forge guy myself, I have often admired the restraint my grinding brothers have shown while being told how inferior their product was because they hadn�t hammered on the steel. This is particularly ironic when one considers the amount of things that can go wrong in the process of forging, making the chances of getting a better knife from a grinder much greater! Nevertheless, there are few topics more rife with controversy than blade forging; this is mostly due to an abundance of wild speculation and gratuitous assumption by people who know little about what they are so boldly speaking of.</p>
<p>I once thought that the blade-making crowd was evolving at such a rate that the superior forged blade nonsense would soon disappear. With more folks having <a href="http://www.cashenblades.com/images/articles/lowdown.html#" style="text-decoration: underline;" id="_GPLITA_0" title="Powered by Text-Enhance">access</a> to good information, and the popularity that forging has enjoyed, my hopes were that by now the craft could stand on its own legitimate merits without having to resort to the shameless old bogus claims. But the same fantastic stuff just keeps being repackaged for a next generations PR.</p>
<p>In response to this sad state, I offer the following paragraphs in hope of shedding enough light on this subject to eliminate some of the misconceptions once and for all, in a format that one would not need an engineering degree to understand. In researching these matters I have concluded that a major portion of <a href="http://www.cashenblades.com/images/articles/lowdown.html#" style="text-decoration: underline;" id="_GPLITA_2" title="Powered by Text-Enhance">science</a> is simply the rewording of common sense and easy to understand general concepts into more precise and specific terms,you know- techno-babble, so I apologize in advance if some of this gets a little heavier than intended.</p>
<p>Why all the wishful thinking about forging? Stock removal consists of but a bar of steel, a grinder, and the will to remove everything that doesn�t look like a knife. Forging involves more output in tools, often a separate shop, plenty of time spent on hot, sweaty and imprecise work that involves burns and an unhealthy dose of respiratory hazards. Perhaps much of the bladesmith�s delusions of grandeur stems from a need to justify all the extra trouble. Another facet of the problem that cannot be ignored is what I like to refer to as �ancestor worship.� You know the routine - all modern products are junk because we either lack the motivation or the wisdom to do it like they did in ancient times. I must admit that in our modern �disposable� society that this can be true of many things but, with something as critical to a civilization as metal production, changes are seldom in the backwards direction. In ages past a smith did need to stand at an anvil for hours on end to produce even the raw materials but, as we will explore, for more reasons than expediency this is no longer the case. The old �they don�t make them like they used to� adage only goes so far. When gravely ill, how many of us would choose a 14th century barber over a 21st century surgeon?</p>
<p>My research has shown me that forging does make superior steel� from the cast ingot! Steel in the ingot, directly from the pouring process, requires heavy reduction and deformation in order to improve its properties by the working out of undesirable conditions, as in redistribution of brittle segregated constituents, closing up porosity and scattering any undesirable inclusions. Because of this, all traditionally poured steels undergo heavy rolling and other mill operations very soon after their creation. It is funny that if one looks at it like this, even stock removers use forged steel. It somewhat smacks of hubris to take a piece of steel that has alread been reduced from feet to fractions of an inch in thickness, hammer a bevel down one side and then proudly <a href="http://www.cashenblades.com/images/articles/lowdown.html#" style="text-decoration: underline;" id="_GPLITA_1" title="Powered by Text-Enhance">claim</a> we have made the steel superior by our forging. Compared to these massive reduction operations, our meager hammering is little more than mostly repeated heat treating and, if one approaches it from the standpoint that if we use the recommended forging temperatures, then it truly does all come down to the heat treat.</p>
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<h2>Going against the grain</h2>
<p>One undeniable aspect of forging things to shape, that we can get out of the way immediately, deals with the directional structure of steel from the aforementioned milling process. This condition is the result of the elongation of impurities, voids and inclusions in the direction of the rolling operation resulting in a wood grain type effect, such that the material will have slightly different properties in one direction than in another.</p>
<p><img src="http://www.cashenblades.com/images/articles/milling.jpg" alt="" height="269" width="432" align="right" border="1"/> In order to avoid a very common confusion, it must be heavily stressed that the term �grain� in this case has nothing to do with the crystalline structure of the metal, such as an �austenite grain,� but instead refers to this directional property, as in �going against the grain,� and is not affected by annealing and other heat treatments. The condition where a property of a material is different in one direction than it is in another is known as �anisotropy,� and we will examine it again later in this discussion.</p>
<p>The quickest and easiest way to demonstrate how forging can affect the properties of a tool via this directional nature is in the classic crank shaft example:</p>
<p><img src="http://www.cashenblades.com/images/articles/cranks.jpg" alt="" height="161" width="288" align="left" border="1"/> If one can imagine these cranks made of wood, they will quickly see the advantages of forging over stock removal in the strength of complex shapes; however, when we are talking shapes as simple as blades the effects would be hardly noticeable. As we will see later, claims that forging aligns �grain� with the edge of a blade are a sneaky play on words that can only effectively apply to this condition if the parent stock was carelessly sheared from a sheet perpendicular to its natural direction.</p>
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<h2>Demythifying the other mythconceptions</h2>
<p>Excluding the minimal effects of the aforementioned directional condition, where does this idea of creating a superior blade by forging or making a better metal by hammering originate? It is a very old concept left over from the days when it was a fact. Before the industrial revolution gave us methods to mass produce molten steel at our bidding, there was the age old process of bloomery steel. A bloom of metal reduced from iron ore never actually reaches a completely liquid state but instead relies upon the chemistry of reduction to create a spongy mass of metal particles that is virtually useless until the smith hammers it solid and forges useable tools from it. For centuries forging wasn�t just a way to make better steel, it was the only way to make steel at all.</p>
<p>Another laurel for the forging process to falsely rest upon seems to revolve around cold working techniques, which are in opposition to most heat treating operations. Before heat treating, mankind relied upon cold hammering metals to make acceptable weapons by altering the properties of the materials. So this is a good place to start our discussion.</p>
<p><img src="http://www.cashenblades.com/images/articles/grainlattice.jpg" alt="" height="283" width="356" align="right" border="1"/> As a metal, steel is crystalline in nature, that is, it is made up of collections of atoms that are arranged in an orderly and repeating pattern. Each individual crystal within the metal has a different lattice work orientation to distinguish it from its neighbors. For illustrative purposes the image to the right shows this as a spaced grid work with lines but, in actuality, try to imagine atoms stacked like ping pong balls or oranges on a fruit stand; ordered rows and layers making an entire stack.</p>
<p>Much of the bad information stems from a gross misunderstanding of the basic process of rearranging these stacks. From impossible suggestions of shrinking matter, to misplaced desires of �breaking� up the internal structures, much of the bladesmith�s claims bear little resemblance to physical fact. The basic law of conservation of matter states that the mass of a system of substances is constant; simple junior high science should have taught us that shrinking existing steel grains is simply not an option. If anybody manages to produce a smaller blade with the same mass as the parent bar, they need to rewrite all the laws that govern our universe. Equally misguided, the smith that aims to break up or fracture internal structures is not doing his blades any favors; while transgranular fracturing is possible, it is very bad.</p>
<p>Going back to the aforementioned laws of conservation, it is fundamental that while matter can neither be created nor destroyed, it can be rearranged. While so many of the bladesmith's fantasies are physically impossible, hammering steel can have its effects all the same by rearranging things in very profound ways. How conditions now drastically change from anything like a fruit stand is that oranges can be squeezed, metal atoms cannot. The atomic stacking of steel, within the context of this article, cannot be condensed tighter, and that is why forging works the way it does. A ball of clay is much softer than steel, but they deform in a similar fashion. If we place that clay in a cylinder and bring a tight sealed piston to bear upon it, no amount of force we could muster would force the piston down beyond the mass of our soft clay. Why should we imagine our stronger steel to be any different? But this stubbornness about being squeezed is a good thing for the process of forging. Be it clay or steel, if we pinch it in one direction it will expand in another; this is how forging steel works and why "packing" steel cannot. If we are going to change the shape of steel we must find a way more in accordance with reality than compacting iron atoms. If we can't get those atoms to squeeze a little closer to accommodate our fantasies, perhaps we can get them to move around each other to achieve our goals, and that is what we will now examine.</p>
<h2>Moving the metal</h2>
<p>Let us establish some terms, the first of which will be deformation. When I say �deformation� in this article, I am referring to a change of original shape for the metal. I will discuss two types of deformation - elastic and plastic. Elastic deformation is a change of shape that is entirely reversible upon removal of the effecting load. A good example of this would be flexing a blade and then having it return to true. Rubber has plenty of elasticity, while steel has much less. Inversely, plastic deformation would be a shape change that is permanent after the load is removed, as in bending a blade and having it stay bent. Plasticity (or ductility as it is described in metals) is very high in clay and much less in steel.</p>
<p>A term you will often see in dealing with metals is �yield� point. Each metal has its own range of elasticity before it yields and permanently (plastically) deforms. This all occurs by movement of the rows of atoms within the metal. Think of our stack of ping pong balls; if you wish to move an entire row or layer you need to push from the side until all of the individual balls will move from their niches in the stacking. If you only push far enough for the top row to move slightly out of their nooks and then back off to let them return to their original positions, you have now duplicated elastic deformation in metal. If you imagine the process occurring over millions of rows of atoms, this would be flexing the steel.</p>
<p>On this stacked atomic level plastic deformation, or forging as we know it, occurs by a mechanism known as slip; the name describes it all. If you keep pushing until the ping pong balls slip into the next niche over, they will remain in that position when the pressure is released and you have now permanently (plastically) deformed the stack of ping pong balls. Translate this to millions of layers of iron atoms and you get a bent piece of steel. As you may have guessed, this is why the process by which metal deforms is called �slip;� it is literally millions of rows of iron atoms slipping over each other.</p>
<p>Slip occurs on optimal planes determined by the stacked arrangement of the atoms (our oranges or ping pong balls). It is easiest to get the layers to move along the direction of tightest stacking. To get a better grasp of this, think of gluing our ping pong balls to two boards in a widely spaced pattern. Put the boards together, ping pong balls to ping pong balls, and begin to tilt the bottom board. You will have to go to a very steep angle before the top board will slip from its position of the nestled ping pong balls. Now do the experiment again, but this time gluing the balls very close together. The top board will now slip at a much lesser angle.</p>
<p><img src="http://www.cashenblades.com/images/articles/pingpong.jpg" alt="" height="236" width="504" align="left" border="1"/> Due to the ordered stacking of iron atoms, there are preferred directions and angles in which slip will occur and others that it will not. Let�s now imagine a single iron crystal as a deck of cards. Push straight down and the deck will be unchanged; put it on edge and it still will not move, but just nudge the side on an angle and the deck will deform and rotate in the direction of push. Each individual crystal in steel can only deform along certain planes but, since the metal is made up of many crystals with a different orientation, some grains will be at the optimal angle for slip to occur and others will not. Those others will be pulled along until the rotation of their orientation offers those choice planes, allowing the metal to deform as a whole in almost any direction.</p>
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<h2>Handy little allotropes</h2>
<p>Each metal has a particular atomic arrangement at room temperature and it is this that gives the metal its working properties and strengths. One stacking arrangement is called <a href="http://www.cashenblades.com/metallurgy.html" title="Gamma Iron"><font color="#00FFFF">face centered cubic (fcc)</font></a>. Fcc offers very tight stacking at very convenient angles so it is quite conducive to slip. Gold is fcc at room temperature and hence it has most desirable working properties.</p>
<p><img src="http://www.cashenblades.com/images/articles/bccfcc.jpg" alt="" height="256" width="288" align="right" border="1"/> Another atomic arrangement is <a href="http://www.cashenblades.com/metallurgy.html" title="Alpha Iron"><font color="#00FFFF">body centered cubic (bcc)</font></a>. Bcc offers larger niches for atoms to rest in and slip has to occur at very odd angles, so metals with this configuration are less ductile, with more elastic deformation than plastic deformation. Iron is bcc at room temperature so it is more difficult to work than gold. But iron has a convenient ability to change stacking arrangements when heated. If you get iron hot enough it will change to fcc, the same arrangement as gold at room temperature. Don�t tell the alchemists that we smiths had it figured out a long, long time ago!</p>
<p>But since iron is normally bcc, working below the critical temperature is slow going and even at 1000�F. can still be called �cold� working since the rate of deformation far exceeds the rate of recrystalization (but we will discuss that some more later).</p>
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<h2>From the atomic lattice to the anvil�s face</h2>
<p><img src="http://www.cashenblades.com/images/articles/dislocation.jpg" alt="" height="229" width="288" align="left" border="1"/>Let�s put this all together and start looking at moving metal. First let's examine how steel moves even when cold. When scientists first started to understand this process, they examined the nature of the atomic stacking in crystals, crunched the numbers, and encountered some problems. If metals were made up of all these perfect, repeating rows of atoms, it should take as much as a thousand times more force to initiate the slip process than what it actually does. Something wasn�t right. So they took a closer look and found the source of the discrepancy. The metal crystals are not perfect but have many little inconsistencies built into them in the form of �vacancies� and �dislocations.� Vacancies are exactly that, a space in the stacking that is empty where an atom should be. For our discussion, however, dislocations are of greater interest, particularly �edge dislocations.� Edge dislocations are a deviation in the stacking where one row is incomplete and causes an odd distortion in the lattice.</p>
<p><img src="http://www.cashenblades.com/images/articles/rug.jpg" alt="" height="252" width="504" align="right" border="1"/>Why are edge dislocations of such interest to us? Because they are responsible for the ability of the humble human arm to move steel. Imagine an enormous area rug that is so heavy one man cannot drag it across the floor, and yet you need to adjust its position slightly. How can it be done? Make a wrinkle or roll in one end and then, like an inch worm, simply chase the roll to the other end! This is how edge dislocations facilitate slip in steel.</p>
<p>However, edge dislocations only make deformation easier until they multiply and accumulate against obstacles like grain boundaries, disproportionate alloying atoms, or other inconsistencies in the stacking. As these pile up, they store the kinetic energy of deformation in potential energy known as strain. In yet another case of extreme irony, as opposed to the utterly false claims of edge packers, fond of low temperature working, reality shows us that cold worked steel is actually <i><b>less dense</b></i>, on a small scale, due to increased vacancies and dislocations. All of this is the basis of work hardening and is very important information for our discussion.</p>
<p>To help in understanding work hardening of metals, I like to visualize a metal crystal as a large cube of blocks made up of hundreds of little blocks all neatly stacked in orderly rows and columns. Choose a random point anywhere in the stack and give one of the rows a push until they move out of alignment. Now choose another side of the stack and do it again. If you continue doing this, the misaligned rows are going to start tangling with each other and it is going to get harder to find a row that will easily slide. Eventually enough misaligned jams will form so that the pile, while not the same original shape at all, will become quite rigid in its new shape. If you continued to push harder without movement, you may succeed in tumbling an entire portion of your stack, and I think we can all guess what this would equate to in our steel!</p>
<p>Strain hardening leads to an anisotropy that is only beneficial, from a strengthening standpoint, in an orientation parallel to the direction of cold working. The opposite applies to the properties in a direction perpendicular to that working. In order to get properties in all directions (i.e., isotropy), a stress-relieving operation will most likely be necessary to re-obtain that uniformity. When discussing the nature of strain hardening it is also worth mentioning that, while ductile strength yield point and hardness are increased, the scratch hardness or the difficulty of cutting or machining is not.</p>
<p>But if we wish to continue to work our metal more, when further force will only result in it coming apart, how do we proceed? Cold metal workers stumbled upon the answer millennia ago and have used it ever since; if bladesmiths are a little slow to catch on, it is because so much of our work already incorporates it at our preferred temperatures.</p>
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<h2>Annealing</h2>
<p>Annealing, is the process of heating cold worked and other strain-laden metals to a temperature at which a number of important things will happen. The first is known as recovery, this is the point in heating where the strain energy will be relieved and the dislocations will be reduced as the lattice relaxes. The next step, when the atomic arrangement begins the change known as recrystalization, will result in entirely new crystals forming to replace the old deformed ones. This process will also occur in steps beginning with nucleation of the new grains at points of highest strain energy, which are usually at the old boundaries and other distortions in the lattice.</p>
<p><img src="http://www.cashenblades.com/images/articles/recrystal.jpg" alt="" height="574" width="216" align="left" border="1"/> In fact many simple metals, those lacking inherent sources of high strain energy, actually require deformation in order to recrystalize upon subsequent reheating. A misinterpretation of this concept may very well be the source of some of the false notions we have about improving steel with hammering. You see, steel is not a simple metal; it is very complex with all kinds of inconsistencies built right into its lattice. Steel can recrystallize every time it is heated to the appropriate temperature with no help at all from the hammer, although hammering can add to the turmoil.</p>
<p>With all this in mind, one needs to reexamine the claims of mechanically refined conditions at any temperature while remembering that any effects from plastic deformation will be rearranged as soon as the metal is heated to anywhere near recrystalization by the very process that makes stress relieving and annealing possible. To be entirely successful, quench hardening heat treatment requires those same processes. Many of the claims of improvements via deformation can be in direct opposition to proper heat treating.</p>
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<p>As we have already discussed, steel will form all new crystals when heated above the recrystallization temperature, and that hammering can add points for this process to occur, but what happens if you hammer at a temperature beyond the recrystallization point? Each hammer blow will introduce energy into a system that is trying to equalize itself; this new energy will then initiate fresh nucleation points and more new grains. Proper forging temperatures are a balance of the need to move the metal and keeping pace with the rate of grain growth. But for all of the frustrations steel can give us, it has some wonderful safety mechanisms built into it that can save the work of even the most incompetent smith.</p>
<p>Since steel has the ability to recrystallize just fine all on its own, a process called �normalizing� becomes very significant to bladesmiths. Quick heating to the recrystallization temperature, while just leaving the poor metal alone to do its thing, will wipe the slate clean, even out all of the problems our inconsistent pounding can bring, and refine the grain better than any of our magic hammer taps.</p>
<p>But what about forging refining the grain? Isn�t that what bladesmiths do? Yes, but a wise smith with the knowledge of what steel is really capable of will get out of its way and let it fix itself much more efficiently. If finer grain is superior for our purposes (and in most cases it is), then why only have finer grain in just the spots our uneven hammer blows managed to catch? Why not relax and let the heated steel do the work and make the entire blade uniformly fine?</p>
<p>Any time I have used various thermal treatments alone to refine grain size, and then compared the fractured grain appearance to samples that I had hammered into submission, the former were always smoother and more uniform in appearance. This should come as no surprise when one considers how complete or uniform one�s hammer blows could be when compared to the action of the entire internal structure of the steel at work. Also worth mentioning is an interesting phenomenon which metallurgists have observed, and bladesmiths need to consider. If steel is only lightly deformed, there will be enough uneven points of nucleation created for many little grains to form around a few large grains. Since large grains grow at the expense of smaller grains, what we have done in this circumstance is created a monster and surrounded it with all it can eat. Overall, this would result in an uneven grain coarsening effect, which one would not have if they had just let the steel do its thing, or at least really moved the steel enough to totally rework it. This would render the idea of �packing� with a few light blows at the end completely counterproductive.</p>
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<h2>What does it all mean?</h2>
<p>In conclusion, after examining all of these facets of a complex process, there are indeed effects that forging can have upon the metal, however, much of it hardly falls into the realm of the fantastic claims that too many bladesmiths prop themselves up on a pedestal with, and the majority of these claims are easily debunked with an elementary understanding of the actual mechanisms at work. Too often the reason bladesmiths need extra ways to refine the steel is in order to fix all the extra abuse they heap upon it in forging it, another one of many odd �Catch-22�s� in the business. The fact is that, unless we just cold work it all and call it good, everything relies upon heating to those temperatures necessary to accomplish any of it. So if we let go of the concept of a hammer doubling as some sort of magic wand, tapping miraculous changes into the steel, and just approach the forging process as another step in heat treatment it could probably make a pretty good blade.</p> Heat Treatments by Kevin R. Cashen, www.cashenblades.comtag:travelingwithintheworld.ning.com,2012-09-01:2185477:Topic:1809212012-09-01T16:44:51.309ZDept of PMM Hall of Steelhttp://travelingwithintheworld.ning.com/profile/HallofSteel
<div align="center">Normalizing</div>
<p><br></br><br></br> The very name of "normalizing" best describes what this operation does; it brings everything inside the steel back to a normal or equalized state. By everything I mean grain size, carbide size and distribution, dislocation densities and stresses resulting from the strain of <a href="http://www.cashenblades.com/heattreatment.html#" id="_GPLITA_3" name="_GPLITA_3" style="text-decoration: underline;" title="Powered by Text-Enhance">working</a> or…</p>
<div align="center">Normalizing</div>
<p><br/><br/> The very name of "normalizing" best describes what this operation does; it brings everything inside the steel back to a normal or equalized state. By everything I mean grain size, carbide size and distribution, dislocation densities and stresses resulting from the strain of <a href="http://www.cashenblades.com/heattreatment.html#" style="text-decoration: underline;" id="_GPLITA_3" title="Powered by Text-Enhance" name="_GPLITA_3">working</a> or thermal effects. The idea is to heat the steel above the recrystallization temperature in order to reset that austenite grains, evenly soak at a temperature sufficient to dissolve large carbide concentrations and in the process wipe out any strain energy that could be in the structure. The most important consideration in normalizing is the heat is as even as possible and that the cooling is as even as possible, but not too slow and not too fast. If one were to cool from normalizing heats too slowly the carbide would diffuse out in rather coarse structures and in places that you may not want them, and thus you would not be normalizing but annealing instead. A slightly faster cooling rate will also promote finer structures, so air cooling is the method used for normalizing, Andy faster than this and you are hardening. Normalizing is used after forging the blade to even out all the chaos inflicted by the hammer. Industry specifies much higher heats for normalizing than many bladesmiths, 1600<sup>o</sup>F.-1700<sup>o</sup>F., and I always <a href="http://www.cashenblades.com/heattreatment.html#" style="text-decoration: underline;" id="_GPLITA_1" title="Powered by Text-Enhance" name="_GPLITA_1">start</a> out with a higher temperature to be certain that I put things into solution. At this first stage I am not so concerned about how fine the grain is but that they are all the same size, uneven grain size can be worse than larger grains, so using the high heat levels the carbide and grain size and actually "normalizes" the inside of the steel. I then follow this heat with two or three more normalizings at subsequently lower heats to step refine the sizes of those constituents. <br/><br/></p>
<div align="center">Annealing</div>
<p><br/><br/> Annealing is the operation by which the qualities of softness, malleability and machineability are achieved. It produces the most stress free state by allowing as much carbon (<a href="http://www.cashenblades.com/metallurgy.html">cementite</a>) to diffuse from the ferrite as possible. It is accomplished by heating a steel to an austenitic condition and then cooling slow enough for thorough diffusion, resulting in the microstructure <a href="http://www.cashenblades.com/metallurgy.html">pearlite</a>. Another process known as spheroidizing is used to create a very soft and machineable state in steel by producing <a href="http://www.cashenblades.com/metallurgy.html">spheroidal cementite</a> microstructures instead of the lamellar structure of pearlite. For more <a href="http://www.cashenblades.com/heattreatment.html#" style="text-decoration: underline;" id="_GPLITA_0" title="Powered by Text-Enhance" name="_GPLITA_0">information</a> on annealing common steels follow the links below.<br/><br/></p>
<div align="center">Hardening</div>
<p><br/><br/> Hardening is the operation in which steel is heated to an austenitic condition and then quenched or rapidly cooled in order to obtain the properties desired in a hardened steel. A microstructure of <a href="http://www.cashenblades.com/metallurgy.html">martensite</a> is the most common goal of hardening. To accomplish this the steel is heated to a temperature above 1335<sup>o</sup>F where the irons atomic stacking will shift to fcc (<a href="http://www.cashenblades.com/metallurgy.html">gamma iron</a>) which has many more spaces for carbon atoms to occupy than at room temperature. The next <a href="http://www.cashenblades.com/heattreatment.html#" style="text-decoration: underline;" id="_GPLITA_2" title="Powered by Text-Enhance" name="_GPLITA_2">step</a>, often referred to as "the soak", the steel is held at the predetermined temperature long enough for the carbon atoms to diffuse through the iron and into those newly created spaces. When this is accomplished the steel is force cooled rapidly enough to trap the carbon in this position and create a supersaturated solution at room temperature. This new condition heavily distorts the atomic stacking resulting in a very hard phase of steel known as martensite. Being the most critical aspect of a quality blade, I leave nothing to chance for this operation. To heat the steel I use an electronically controlled molten bath of NaCl based salts capable of holding exact temperatures very evenly. Since each steel will have it own particular cooling requirements I utilize several quench mediums formulated by industry specifically for the task, ranging from state of the art heat treating oils to low temperature molten salts.<br/><br/> <b><u>Tempering</u></b> <br/><br/></p>
<div align="left">Tempering is very often, and very incorrectly, confused with hardening. Fully hardened steel has its normal <a href="http://www.cashenblades.com/metallurgy.html">bcc</a> atomic configuration distorted into a tetragonal state due to the carbon atoms that were trapped in the interstitial spaces by the rapid cooling of the quench. This "unnatural" state, known as alpha martensite, is under much stress from the strain induced hardeness, also making it brittle. While this results in high abrasion resistance and strength, it renders the steel useless for operation requiring impact strength or toughness. To correct this, a "compromise" must be made through tempering. In the tempering process the martensitic steel is heated just enough to release some of the trapped carbon atoms to a desired degree, reducing stress and increasing toughness as it is transformed to beta martensite. Not only does this increase toughness and ductility but it reduces the chance of distortion or cracking from hardening. This is why tempering should be done as soon as possible after the martensitic transformation has completed. So, very contrary to the popular misuse of the word, tempering can actually be called the opposite of hardening. Different steels, due to varying alloy compositions, have different temperature ranges to achieve the desired results. In tempering the end result is effected by two factors, time and temperature. Of these, temperature has the most immediate and profound affect. Time at temperature has a more subtle effect, relieving stresses and increasing toughness with less loss of hardness.</div> Forging by Kevin R. Cashen, www.cashenblades.comtag:travelingwithintheworld.ning.com,2012-09-01:2185477:Topic:1811182012-09-01T16:43:47.696ZDept of PMM Hall of Steelhttp://travelingwithintheworld.ning.com/profile/HallofSteel
<p>There are as many different ways of forging a knife as there are smiths forging them, and that is just fine. Your style of forging is what defines your look or style of knives, and despite strong opinions on how it should be done, you have to do what works for you. There is no wrong or right way to accomplish the end result as long as you accomplish it. But there are a couple of facts to keep in mind when determining which way is best for you. Every time you put energy into steel, be it heat…</p>
<p>There are as many different ways of forging a knife as there are smiths forging them, and that is just fine. Your style of forging is what defines your look or style of knives, and despite strong opinions on how it should be done, you have to do what works for you. There is no wrong or right way to accomplish the end result as long as you accomplish it. But there are a couple of facts to keep in mind when determining which way is best for you. Every time you put energy into steel, be it heat or mechanical there are infinite ways to mess it up and just a handful of ways to improve it for your purposes. The idea here is to get the <a href="http://www.cashenblades.com/forging.html#" style="text-decoration: underline;" id="_GPLITA_0" title="Powered by Text-Enhance" name="_GPLITA_0">job</a> done with the least amount of messing around with it. Without enough heat it will take too long and require too much mechanical energy for plastic deformation. Without enough properly applied hammer blows it will take too much time and require too much heat. Too much heat results in heavy segregation of micro constituents, marked grain growth and decarburization. Too much time results in loss of material due to oxide scale, pitting and messy surfaces and most of all, decarburization. <br/> <br/> Have you noticed a word reappearing here? Decarburization is one of those facts of nature that is almost unavoidable, regardless of all our wishful thinking, due to the laws of physics and chemistry. The carbon is something we need in the steel in order for it to behave predictably in the ways we wish it to. It has a liking for iron and will remain there if not tempted by something that it likes better. Oxygen is something that is likes better. The air all around us is 21% oxygen; at room temperature this is not a problem since the carbon atoms are held quite snugly by their iron partners. But as temperature increases carbon atoms get quite restless, since carbon is and interstitial element in steel is free to move between the iron atoms when the space is freed up. At temperatures above Ac1 carbon is capable of bonding with oxygen and leaving the steel entirely, this increases with higher temperatures. This causes decarb to be present in almost all forging operations, and the never-ending goal is to minimize it as much as possible. If it survives to the finish product it will manifest itself in some disturbing ways. Knives will not hold and edge properly until they have been sharpened a couple of times, the decarbed edge is finally wore away, and then they will finally cut. Pattern welded blades will have splotchy etches where the decarb on the surface is affected differently. The nasty stuff can even cause warpage due to the unevenness of structure along the surface of the blade. You should always leave enough material on your forgings to allow for the �skin� of decarb, which will be exacerbated by the anneal, to be removed in the grinding. When we first <a href="http://www.cashenblades.com/forging.html#" style="text-decoration: underline;" id="_GPLITA_1" title="Powered by Text-Enhance" name="_GPLITA_1">start</a> out this extra material will have to be a little thicker until we find the most efficient way to get the job done. <br/> <br/> For every steel there is a recommended forging temperature, some are higher and some area little lower but all are above Ac1. If we go too high we might have the disturbing experience of watching steel come apart, or �mush up�, on the anvil, steels that do this at lower temperatures are referred to as �red short� by the old timers. In my shop �white hot� is never acceptable in any operation, forging, welding or heat-treating, it is not necessary or good for the steel. The fireworks display of sparks from burning steel is shunned by most smiths <a href="http://www.cashenblades.com/forging.html#" style="text-decoration: underline;" id="_GPLITA_2" title="Powered by Text-Enhance" name="_GPLITA_2">working</a> with high carbon steels. I have heard some say that all you have to do is forge it back down and normalize, but if you have a good look at the steel in that area it is never quite the same as the rest. <br/> <br/> Strangely enough, too low of a temperature is the most common forging problem I see with my students. Perhaps they only need to see that steel burn once to become quite heat shy, and I am continually telling them to get it hot enough to move it. If the forging is �mushrooming� and taking on an I-beam configuration in cross section, only the outer surface metal is being moved and there is insufficient heat to move the center of the cross section. Ac1 is quite low for most forging heats, anything below Ac1 is cold working and steel can only take so much of this. <br/> <br/> <br/> <br/> <img src="http://www.cashenblades.com/images/forging/forging1.jpg" alt="" title="" height="439" width="415" align="left" border="0"/><br/> <br/><br/> <br/> <br/> This is how I forge a typical hunter blade, it is not right or wrong, it is the just the most efficient for me. I liken blade forging to stir frying, another thing that I enjoy doing. In stir frying a good Chinese meal the idea to making it good is to do it hot and fast. In order to do this with ease, the ingredients are cut and prepared before hand and put in little containers, ready to be immediately thrown into the pan when needed. I think blades should be forged quickly with the least amount of banging and overheating. Over heating occurs much more easily in thinner sections while trying to get thicker areas hot, so to me the best way is one that exposes thinner sections to the least overeating. Thinner sections would be the edge and the tip, also the most critical to be right on a knife, so I consider these parts to be the actual �stir frying� operation that is done quickly and then the blade is conceived an I am done. The profile and heavy reduction operations are done at slightly higher temperatures and are the �preparation� or �setup�. As I progress closer to a finished knife my heats get a little cooler for more precise control and less overheating. <br/> <br/> <br/> The first few operations are heavy profile reductions so I do them at a higher forging temperature 1800F-1900F. The first of these operations is putting a point on the bar of steel. Once again, it really needs to be hot for this operation since the idea is to pull the corners from the end of the bar back into the length. Hammering from the sides or directly into the corners will only result in a �cup� or �birds mouth� at the end of the bar that will not go away and be forged into the tip, making a real mess. I put the end of the bar over the edge of the anvil and hammer on the end, pulling the corners back into the bar. <br/> <br/><br/> <br/> <img src="http://www.cashenblades.com/images/forging/forging2.jpg" alt="" title="" height="295" width="432" align="right" border="0"/><br/><br/> <br/> <br/><br/> Once the point is established, for a clip point, I hammer it to one side so that the side that will be the edge is straight and the future spine clips down to form a point. Next I establish where the edge will begin and the ricasso/choil will be, by drawing the edge down at this point and roughing-in what will be the grind shoulders. The expansion of the metal in this action will cause the would-be blade to kick up as it develops a curve in that the worked area. This is not a problem since all of that will be dealt with next. <br/> <br/><br/> <br/> <br/> <br/> <img src="http://www.cashenblades.com/images/forging/forging3.jpg" alt="" title="" height="310" width="432" align="left" border="0"/><br/> <br/> <br/><br/> <br/> <br/> The next heat is in the same area of the ricasso, edge junction. The choil area is sat on the anvil with the blade heel overhanging where you want the choil/edge angle to be. Most folks who first try this almost always let the edge get up on the anvil and smash it down real badly and ruin what they have started. I give a hammer blow directly over the choil area, which refines the ricasso/choil/edge junction quite well, and then hammer out on the spine of the blade to take out the upward curve. I do not stop at straight, however, I continue to bend the tip down until the whole thing has a serious re-curve. I will often take a second heat and put the future edge on the anvil horn that put more curvature in. <br/> <br/> I know this looks like a really strange thing to do but I will explain. This is still all �setup for the stir fry�. When the edge bevel is forged in it will expand, steel cannot be �packed� if you squeeze it, it must flow. Since it is not worked the spine will sit still, so the expansion of the edge vs. the spine will cause the blade to take an uncontrolled curve upward. This is great if you want a Shamshir, but if you want a straight hunter you will have to fight the steel in this action. I have watched many other people forge blades and take some time fighting with the metal. They hammer on the bevel and then pound the spine back down, which wrinkles and mushrooms the edge then they straighten it all out and hammer on the bevel, which starts the whole process over again. Not only does it take a lot more pounding and a lot more heats but what is this doing to the most critical part of the knife, the edge? To me a better way has got to be not to fight with the steel, let it play it�s games, but I make the rules to that game. The re-curve is not a new idea but it does take the aggravation out of things by compensating for the expansion. Now instead of curving, the blade straightens itself while the bevels are forged in. Now all of the preparation is done and I am ready to �stir fry�. <br/> <img src="http://www.cashenblades.com/images/forging/Forging5.jpg" alt="" title="" height="432" width="432" align="right" border="0"/> <br/> <br/><br/> <br/><br/> <br/><br/> <br/> Quite often I can forge in the bevels on a 5� hunters in just a couple of heats. Since everything is set and ready, all I have to do is heat it up and zip up the edge with the hammer. I also will incorporate any balancing taper at this time, using it to add width to the blade and affect curvature without having to resort to setting the blade on edge and hitting it. Now that the blade is formed and the edge is done there is no reason to over heat the smaller portions by further working in thicker cross sections. <br/> <br/><br/> <br/> <br/> <br/> <br/> <img src="http://www.cashenblades.com/images/forging/forgiing6.jpg" alt="" title="" height="318" width="432" align="left" border="0"/><br/> <br/> <br/><br/> <br/> The next heat will be at a much lower temperature in order to smooth things out and straighten without scaling or heavy metal movement. I have heard this referred to as �hammer polishing� and the term is very appropriate. And I am quick to point out that this is what I am doing and not �edge packing�. <br/> <br/> Even though I am very careful, I know that I have probably made a good jumbled mess of the internal structure of the steel so the last thing I do is to heat the blade as evenly as possible to above Acm and let it cool as evenly as possible in the air to normalize it. I do this at least twice and preferably three times with the next heat a little cooler than the last. I will also throw a quench in the lineup, for serious grain refinement, if I think there has been a grain size problem or I am working with shallow hardening steel.</p> Steel Selection by Kevin R. Cashen, www.cashenblades.comtag:travelingwithintheworld.ning.com,2012-09-01:2185477:Topic:1808452012-09-01T16:39:56.898ZDept of PMM Hall of Steelhttp://travelingwithintheworld.ning.com/profile/HallofSteel
<p class="MsoNormal"><font color="#FFFFFF">With the plethora of steels available today one can easily get lost in just selecting the one to use.<span style="mso-spacerun: yes;"> </span> Each steel has its own chemical composition suited for the task for which it was made.<span style="mso-spacerun: yes;"> </span> Alloying elements affect the qualities and characteristics of steel in many ways and it is worth knowing what some of those are.</font></p>
<p><font color="#FFFFFF"> …</font></p>
<p class="MsoNormal"><font color="#FFFFFF">With the plethora of steels available today one can easily get lost in just selecting the one to use.<span style="mso-spacerun: yes;"> </span> Each steel has its own chemical composition suited for the task for which it was made.<span style="mso-spacerun: yes;"> </span> Alloying elements affect the qualities and characteristics of steel in many ways and it is worth knowing what some of those are.</font></p>
<p><font color="#FFFFFF"> </font></p>
<table cellspacing="0" width="100%" bgcolor="#FFFFFF" border="1">
<tbody><tr><td>Alloy Element</td>
<td>Positive Effects Upon Steel</td>
<td>Negative Effects Upon Steel</td>
</tr>
<tr><td>Carbon</td>
<td>Hardness, Strength, Abrasion Resistance</td>
<td>Embrittlement, Excess Carbides</td>
</tr>
<tr><td>Chromium</td>
<td>Corrosion Resistance, Hardenability</td>
<td>Red short, Retains Carbides</td>
</tr>
<tr><td>Manganese</td>
<td>Desulfurization, Strength, Hardenability, Wear Resistance</td>
<td>Lower Plasticity</td>
</tr>
<tr><td>Nickel</td>
<td>Toughness, Strength</td>
<td> </td>
</tr>
<tr><td>Silicon</td>
<td>Deoxidizing agent, Hardenability, Toughness</td>
<td> </td>
</tr>
<tr><td>Tungsten</td>
<td>High Temperature Strength, Abrasion Resistance, Grain Refiner</td>
<td>Red Hardness, Retains Carbides</td>
</tr>
<tr><td>Molybdenum</td>
<td>High Temperature Strength, Hardenability</td>
<td>Red Hardness</td>
</tr>
<tr><td>Vanadium</td>
<td>Grain Refinement, Toughness, Abrasion Resistance.</td>
<td>Some Red Hardness,Retains Carbides</td>
</tr>
<tr><td>Sulfur</td>
<td>Machinability</td>
<td>Embrittlement</td>
</tr>
<tr><td>Phosphorus</td>
<td>Machinability</td>
<td>Dendritic-banding structures resulting in weakness</td>
</tr>
</tbody>
</table>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><font color="#FFFFFF">To add to the confusion there are a few different classification systems of steel that identify the alloy chemistry or its characteristics.<span style="mso-spacerun: yes;"> </span> The most common are the Number designations of the American Iron and Steel Institute (AISI) and the Society of <a href="http://www.cashenblades.com/steel/steelselection.html#" style="text-decoration: underline;" id="_GPLITA_1" title="Powered by Text-Enhance" name="_GPLITA_1">Automotive</a> Engineers (SAE).<span style="mso-spacerun: yes;"> </span> In this numerical system the first two numbers refer to the alloy content and the second two (or three) numbers refer to the carbon content.</font></p>
<p class="MsoNormal"> </p>
<center>AISI/SAE Steel Classifications</center>
<table cellspacing="0" width="100%" bgcolor="#FFFF99" border="1">
<tbody><tr><td>10XX</td>
<td>Nonsulfurized Carbon Steels</td>
</tr>
<tr><td>11XX</td>
<td>Resulfurized Carbon Steels (Free Machining)</td>
</tr>
<tr><td>12XX</td>
<td>Rephosphorized & Resulfurized Carbon Steel</td>
</tr>
<tr><td>13XX</td>
<td>Manganese 1.75 (Principle Alloy)</td>
</tr>
<tr><td>23XX</td>
<td>Nickel 3.5</td>
</tr>
<tr><td>25XX</td>
<td>Nickel 5.00</td>
</tr>
<tr><td>31XX</td>
<td>Nickel 1.25; Chromium 0.65</td>
</tr>
<tr><td>33XX</td>
<td>Nickel 3.50; Chromium 1.55</td>
</tr>
<tr><td>40XX</td>
<td>Molybdenum 0.20 or 0.25</td>
</tr>
<tr><td>41XX</td>
<td>Chromium 0.50 or 0.95; Molybdenum0.12 or 0.20</td>
</tr>
<tr><td>43XX</td>
<td>Nickel 1.80; Chromium 0.50 or 0.80; Molybdenum 0.25</td>
</tr>
<tr><td>44XX</td>
<td>Molybdenum 0.40</td>
</tr>
<tr><td>45XX</td>
<td>Molybdenum 0.52</td>
</tr>
<tr><td>46XX</td>
<td>Nickel 1.80; Molybdenum 0.25</td>
</tr>
<tr><td>47XX</td>
<td>Nickel 1.05; Chromium 0.45; Molybdenum 0.20 or 0.35</td>
</tr>
<tr><td>48XX</td>
<td>Nickel 3.50; Molybdenum 0.25</td>
</tr>
<tr><td>50XX</td>
<td>Chromium 0.25; 0.40 or 0.50</td>
</tr>
<tr><td>50XXX</td>
<td>Carbon 1.00; Chromium 0.50</td>
</tr>
<tr><td>51XX</td>
<td>Chromium 0.80, 0.90, 0.95, 1.00</td>
</tr>
<tr><td>51XXX</td>
<td>Carbon 1.00; Chromium 1.05</td>
</tr>
<tr><td>52XXX</td>
<td>Carbon 1.00; Chromium1.45</td>
</tr>
<tr><td>61XX</td>
<td>Chromium 0.60, 0.80, 0.95; Vanadium 0.12</td>
</tr>
<tr><td>81XX</td>
<td>Nickel 0.30; Chromium 0.40; Molybdenum 0.12</td>
</tr>
<tr><td>86XX</td>
<td>Nickel 0.55; Chromium 0.50; Molybdenum 0.20</td>
</tr>
<tr><td>87XX</td>
<td>Nickel 0.55; Chromium 0.50; Molybdenum 0.25</td>
</tr>
<tr><td>88XX</td>
<td>Nickel 0.55; Chromium 0.50; Molybdenum 0.35</td>
</tr>
<tr><td>92XX</td>
<td>Manganese 0.85; Silicon 2.00; Chromium 0.35</td>
</tr>
<tr><td>93XX</td>
<td>Nickel 3.25; Chromium 1.20; Molybdenum 0.12</td>
</tr>
<tr><td>94XX</td>
<td>Nickel 0.45; Chromium 0.40; Molybdenum 0.12</td>
</tr>
<tr><td>98XX</td>
<td>Nickel 1.00; Chromium 0.80; Molybdenum 0.25</td>
</tr>
</tbody>
</table>
<p><br/><br/></p>
<p class="MsoNormal">Another Classification of steels is that of Tool steels and is divided into groups according to their <a href="http://www.cashenblades.com/steel/steelselection.html#" style="text-decoration: underline;" id="_GPLITA_0" title="Powered by Text-Enhance" name="_GPLITA_0">application</a>, method of quench or special characteristics.</p>
<p><br/></p>
<center>Tool Steel Classifications</center>
<table cellspacing="2" width="100%" bgcolor="#CCFFFF" border="2">
<tbody><tr><td>Category</td>
<td>Example</td>
<td>Description</td>
</tr>
<tr><td>A</td>
<td>A2</td>
<td>Air Hardening</td>
</tr>
<tr><td>D</td>
<td>D2</td>
<td>Die Making Steel</td>
</tr>
<tr><td>F</td>
<td>F1</td>
<td>Special Purpose (Carbon-Tungsten)</td>
</tr>
<tr><td>H</td>
<td>H10</td>
<td>Hot Working</td>
</tr>
<tr><td>L</td>
<td>L6</td>
<td>Low Alloy</td>
</tr>
<tr><td>M</td>
<td>M10</td>
<td>High Speed (Molybdenum)</td>
</tr>
<tr><td>O</td>
<td>O1</td>
<td>Oil Hardening</td>
</tr>
<tr><td>P</td>
<td>P5</td>
<td>Mold Making</td>
</tr>
<tr><td>S</td>
<td>S7</td>
<td>Shock Resistant</td>
</tr>
<tr><td>T</td>
<td>T2</td>
<td>High Speed (Tungsten)</td>
</tr>
<tr><td>W</td>
<td>W2</td>
<td>Water Hardening</td>
</tr>
</tbody>
</table>
<p><br/><br/></p>
<p class="MsoNormal"><font color="#FFFFFF">Before you make any kind of tool, or anything for that matter, you must first know what it is that you wish to make or accomplish.<span style="mso-spacerun: yes;"> </span> Think about it, when man came up with catapults he didn’t build a big gangly contraption and then ask “OK now what can we do with this thing?<span style="mso-spacerun: yes;"> </span> Hey lets try throwing stuff with it!”.<span style="mso-spacerun: yes;"> </span> Man had a need to hurl massive missiles at long distances so he sat down and started planning a way to do it.</font></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="mso-spacerun: yes;"> </span> Quite often I see blades done in the backwards manner previously described.<span style="mso-spacerun: yes;"> </span> Would be makers find a piece of steel and then build a blade around it.<span style="mso-spacerun: yes;"> </span> First, determine what your knife should have to do.<span style="mso-spacerun: yes;"> </span> If it will be a scalpel, it can be very hard or perhaps stainless.<span style="mso-spacerun: yes;"> </span> A specialized skinning knife will have edge holding and abrasion resistance as a top priority.<span style="mso-spacerun: yes;"> </span> A large camp knife or sword will require good shock resistance to take the pounding of hacking and chopping.<span style="mso-spacerun: yes;"> </span> So plan the knife and then determine the steel and the techniques to best achieve your goal.</p>
<p><font color="#FFFFFF"><font color="#FFFFFF"><br/> Other considerations for steel besides the desired performance are your abilitites to work with a given alloy. Are you forging or stock removing? If you are forging some of these steels may present a serious challenge that may have you asking if it is worth the trouble. The simpler the steel the simpler can be the tools used to work it to satisfactory results. With all the things that can go wrong in forging the simpler alloys seem to be the best bet. Air hardening, hot hard and steels that may crack if worked improperly may be beyond a beginners abilities or even beyond the usefulness of such techniques at all. There are always those that say that they have forged good blades from very complex alloys, but are we pounding square pegs into round holes? The same quality knife (or better) could have been made much more easily with a steel better suited for the purpose. If you hear about all kinds of wild techniques and heat treating practices being done on a steel to make it really perform well, don't say "wow,that must be some steel" but instead ask if another steel could have done the job better without all the trouble. Even if you are just stock removing, the steel will have to be heat treated, are you and your equipment up to the challenge of some of the richer alloys? <br/></font></font></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="mso-spacerun: yes;"> </span> How do you determine which steel is best for a given application?<span style="mso-spacerun: yes;"> </span> Fortunately this work has already been done for you.<span style="mso-spacerun: yes;"> </span> Industry has spent many years and countless dollars researching, developing and making steels specifically for certain applications.<span style="mso-spacerun: yes;"> </span> Why reinvent the wheel?<span style="mso-spacerun: yes;"> </span> Just use all the information that they have already set up for you. Once again many makers seem to wish to ignore this helpful information and force square pegs into round holes.<span style="mso-spacerun: yes;"> </span> Not that it can’t be done with a big enough hammer, but the round pegs fit much easier with less wear on you and your pegs.</p>
<p><font color="#FFFFFF"><br/> In the table below you will find commonly available steels, their chemical composition and typical applications in which the are used. The ones that are highlighted may be clicked upon to take you to further information, including the Crucible Service Center or Admiral Steel page with all the the pertinent heat treating specifications and data. From there just one or two clicks should get you to ordering the steel of your dreams. Or if you wish to bypass my silly games and recommendations you can go directly to the home page of some the the bigger steel suppliers:</font> <br/><a href="http://www.admiralsteel.com/">Admiral Steel</a><br/><a href="http://www.cartech.com/">Carpenter Specialty Steels</a><br/><a href="http://www.crucibleservice.com/">Crucible Service Centers</a></p>
<p class="MsoNormal"> </p>
<table cellspacing="2" width="100%" bgcolor="#CCFFCC" border="2">
<tbody><tr><td>Type</td>
<td>C</td>
<td>CR</td>
<td>Mn</td>
<td>Mo</td>
<td>Si</td>
<td>W</td>
<td>V</td>
<td>Other</td>
<td>Typical Applications</td>
</tr>
<tr><td>A2</td>
<td>1.0</td>
<td>5.25</td>
<td>.85</td>
<td>1.10</td>
<td>.35</td>
<td>-</td>
<td>.25</td>
<td>-</td>
<td>Blanking Dies, Thread Roll Dies, Forming Tools, Shear Blades, Gauges, Wear Inserts, forming rolls, hog knives, thread rollers, bending dies, cold blanking dies, coining dies, cold trimming dies, punches etc.</td>
</tr>
<tr><td>A6</td>
<td>.70</td>
<td>1.0</td>
<td>2.0</td>
<td>1.35</td>
<td>.30</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Dies,Compression Molds, Lens Molds,Injection Molds, Transfer Molds</td>
</tr>
<tr><td>D2</td>
<td>1.55</td>
<td>11.5</td>
<td>.35</td>
<td>.80</td>
<td>.45</td>
<td>-</td>
<td>.80</td>
<td>-</td>
<td>Blanking Dies, Thread Roll Dies, Drawing Dies,Coining Dies,Trim Dies, Mold Inserts, Forming Rolls, Gauges, Injection Screw Components, burnishing tools, gauges, lathe centers.</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/l6.html">L6</a></td>
<td>.75</td>
<td>.80</td>
<td>.70</td>
<td>.30</td>
<td>.25</td>
<td>-</td>
<td>-</td>
<td>1.5 Ni</td>
<td>Circular saws, Wood cutting band saws, Chipper & planer blades, Form Rolls, Straightening Rolls, Brake Dies, Shear Blades, Machine Tool Parts, Collets, Chucks, Pinions</td>
</tr>
<tr><td>M2</td>
<td>.85</td>
<td>4.15</td>
<td>.30</td>
<td>5.0</td>
<td>.30</td>
<td>6.4</td>
<td>2.0</td>
<td>-</td>
<td>Tools for heavy machining- Broaches, Milling Cutters, Counterbores, End Mills, Taps, Form Tools, Tool Bits,</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/o1.html">O1</a></td>
<td>.90</td>
<td>.50</td>
<td>1.25</td>
<td>-</td>
<td>.30</td>
<td>.5</td>
<td>-</td>
<td>-</td>
<td>Abrasion resistant cutting tools- Blanking Dies,Jewelers Hobs, Engraving Tools, Paper Knives, Forming Tools, Taps (Hand), Gauges, Trim Dies, Broaches, drill bushings, knurling tools, reamers, taps, cold forming and bending dies, master tools, drawing dies, punches,coining dies, plastic molds, rubber molds etc..</td>
</tr>
<tr><td>O6</td>
<td>1.50</td>
<td>-</td>
<td>.75</td>
<td>.25</td>
<td>1.0</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Parts requiring easy machining- Gauges, Bushings, Blanking Dies, Perforating Dies, Draw Dies.</td>
</tr>
<tr><td>S5</td>
<td>.60</td>
<td>.25</td>
<td>.85</td>
<td>.30</td>
<td>1.90</td>
<td>-</td>
<td>.20</td>
<td>-</td>
<td>Tools subjected to repeated heavy impact- Heading Tools, Chisels, Shear Blades, Rivet Sets, Concrete Breakers, Stamps, Hammers, Hand Tools.</td>
</tr>
<tr><td>S7</td>
<td>.55</td>
<td>3.25</td>
<td>.70</td>
<td>1.40</td>
<td>.35</td>
<td>-</td>
<td>.25</td>
<td>-</td>
<td>Punches and Dies Subject to Heavy Impact, Wire EDMed Punches & Dies, Warm Forging/Heading Dies, Plastic Injection Molds.</td>
</tr>
<tr><td>1060</td>
<td>.55-.65</td>
<td>-</td>
<td>.60-.90</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Hand tools, shims,rule dies,scrapers.</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/1080.html">1080</a></td>
<td>.65-.75</td>
<td>-</td>
<td>.60-.90</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Hand tools, shims, rule dies,scrapers.</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/1084.html">1084</a></td>
<td>.80-.93</td>
<td>-</td>
<td>.60-.90</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Blades, hand tools,shims, & springs,rule dies,scrapers</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/1095.html">1095</a></td>
<td>.9-1.03</td>
<td>-</td>
<td>.30-.50</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Blades, hand tools, knives, shims, & springs, Flat & coil springs, rule dies,scrapers, & trowels</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/5160.html">5160</a></td>
<td>.55-.64</td>
<td>.70-.90</td>
<td>.75-1.00</td>
<td>-</td>
<td>.15-.30</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Leaf springs, Coil springs, scrapers, equalizers, bumpers,</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/52100.html">52100</a></td>
<td>1.0</td>
<td>1.5</td>
<td>.35</td>
<td>-</td>
<td>.25</td>
<td>-</td>
<td>-</td>
<td>-</td>
<td>Ball Bearings, Roller Bearings, Bearing Races, Gauges, Drawing Dies, Mandrels, Drills (Non-Ferrous).</td>
</tr>
<tr><td><a href="http://www.cashenblades.com/steel/W2.html">W2</a></td>
<td>.60-1.40</td>
<td>.15 max</td>
<td>.10-.40</td>
<td>-</td>
<td>.10-.40</td>
<td>-</td>
<td>.25</td>
<td>-</td>
<td>Blanking tools, Chisels, Shear blades, Drills, Glass Cutters,Lathe tools, Reamers, Hand Taps and Dies,Twist Drills,Woodworking Tools,Wear Plates, Razor Blades.</td>
</tr>
</tbody>
</table>
<p class="MsoNormal"> </p>
<p class="MsoNormal">The list above is not to be read in reverse, it is meant to tell you what the steels are best suited for, not what old rusty junk could be made of.<span style="mso-spacerun: yes;"> </span> The first commandment of bladesmithing is KNOW THY STEEL.<span style="mso-spacerun: yes;"> </span> Scrap or mystery steel is great for forging or grinding practice, but if you are going to heat-treat it you have to know your parameters (you have to know what it is).<span style="mso-spacerun: yes;"> </span> If you are going to take it all the way to a finished product isn’t it worth knowing it will be the best you can get when you are done with all that work?<span style="mso-spacerun: yes;"> </span> You owe it to yourself and your customers to do it right.<span style="mso-spacerun: yes;"> </span> You hear it again and again, “Old saw blades should be L6”, “leaf springs should be 5160” “files should be W2”, if there is any "shoulds" or guesses involved you have already compromised your results.<span style="mso-spacerun: yes;"> </span> Saws, springs, files etc. have all changed over the years and can have anything in them at any given manufacturers whim. Many people have been unpleasantly surprised to find that the seemingly hard objects that they made their blades out of were just surfaced hardened soft steel, a practice becoming more popular for its cost savings in industry. So don’t be surprised that if the blade you made out of old junk is, well…junk!<span style="mso-spacerun: yes;"> </span> The absolute worst reason for this practice is cost savings, as this is a very false economy.<span style="mso-spacerun: yes;"> </span> The time and materials wasted on an unacceptable blade made from mystery steel is far more expensive than the priciest steels out there.<span style="mso-spacerun: yes;"> </span> Most steel in blade size sections are surprising inexpensive and can be delivered right to your doorstep, with chemical analysis and heat treating specifications, with just one phone call.<span style="mso-spacerun: yes;"> <br/></span></p> Basic Metallurgy by Kevin R. Cashen, www.cashenblades.comtag:travelingwithintheworld.ning.com,2012-09-01:2185477:Topic:1808422012-09-01T16:38:55.906ZDept of PMM Hall of Steelhttp://travelingwithintheworld.ning.com/profile/HallofSteel
<p>I have assembled this page as an introduction to some of the basic metallurgy involved in bladesmithing. The starting point of any blade is steel, an alloy of iron with a little carbon added, but iron has an interesting property which allows bladesmiths to do extraordinary things with it. <br></br><br></br></p>
<div align="center"><b><u>Allotropes of Iron</u></b> <br></br><br></br> <img align="left" alt="" border="0" height="288" src="http://www.cashenblades.com/images/info/bcc.jpg" title="" width="288"></img> <img align="right" alt="" border="0" height="288" src="http://www.cashenblades.com/images/info/fcc.jpg" title="" width="288"></img> Iron is able to exist in different phases, or atomic stacking, based upon its temperature. At room…</div>
<p>I have assembled this page as an introduction to some of the basic metallurgy involved in bladesmithing. The starting point of any blade is steel, an alloy of iron with a little carbon added, but iron has an interesting property which allows bladesmiths to do extraordinary things with it. <br/><br/></p>
<div align="center"><b><u>Allotropes of Iron</u></b> <br/><br/> <img src="http://www.cashenblades.com/images/info/bcc.jpg" alt="" title="" height="288" width="288" align="left" border="0"/><img src="http://www.cashenblades.com/images/info/fcc.jpg" alt="" title="" height="288" width="288" align="right" border="0"/>Iron is able to exist in different phases, or atomic stacking, based upon its temperature. At room temperature iron is crystalline structure with its atoms stacked in a cubic arrangement with an extra atom in the center. This body centered cubic (bcc) iron is known as alpha iron and only has so many spaces to accommodate carbon atoms between the iron. At temperatures above 1335 <a href="http://www.cashenblades.com/metallurgy.html#" style="text-decoration: underline;" id="_GPLITA_1" title="Powered by Text-Enhance" name="_GPLITA_1">degrees</a> Fahrenheit the atomic stacking of iron changes to a cube with an extra iron atom on the middle of each face of that cube. This face centered cubic phase is known as gamma iron, and it has many more spaces for carbon to rest between the iron than room temperature alpha iron. <br/><br/></div>
<p><br/> <br/> <br/> <br/> <br/> <br/> <br/> <br/> <br/> <img src="http://www.cashenblades.com/images/info/ferrite.jpg" alt="" title="" height="360" width="360" align="left" border="0"/><br/> <br/> <br/> <br/> <br/></p>
<div align="center">Ferrite</div>
<p><br/> The predominantly iron portion of steel. Since it holds relatively small amounts of carbon proeutectoid ferrite, like in the image to the left, occurs in alloys with less than .80% carbon.<br/> <br/> <br/> <br/> <br/> <br/><br/> <br/> <br/> <img src="http://www.cashenblades.com/images/info/cementite.jpg" alt="" title="" height="232" width="360" align="right" border="0"/> <br/><br/></p>
<div align="center">Cementite</div>
<p><br/> Cementite or iron carbide (Fe3C) is the form that carbon takes in steel, cast iron and other iron-carbon alloys. It is a compound of 93.33% iron and 6.67% carbon by weight, but occurs in alloys, in the form of proeutectoid cementite, above .83%C. Pictured is cementite (white) in the grain boundaries of 1095 steel, not a desirable condition.<br/> <br/><br/> <br/> <br/><br/></p>
<div align="center"><b><u>Austenite</u></b></div>
<p><img src="http://www.cashenblades.com/images/info/austenite.jpg" alt="" title="" height="355" width="360" align="left" border="0"/><br/>Named for Sir W.C. Roberts Austen this is a solid solution structure in which gamma iron is the solvent with carbon or iron carbide as the solute. Austenite is the state of iron/carbon that most of the structures (martensite, pearlite, bainite etc...) used in bladesmithing are derived from. Upon heating to the temperature designated ac1 alpha iron makes the allotropic shift from Body centered cubic to face centered cubic gamma iron. Gamma iron is capable of holding much more carbon in solution and begins to accept carbon into the iron atomic matrix. Holding higher amounts of carbon in solution in the FCC configuration causes austenite to be unstable at temperatures below ar1. Upon slow cooling carbon will diffuse to form pearlite from the parent austenite. If rapidly cooled austenite will be unable to diffuse carbon sufficiently enough to form pearlite and the result will be martensite or bainite depending upon the rate of cooling. In many ways austenite is the parent of the other microstructures, not only from the standpoint that the other structures arise from its decomposition but also that it provides the framework for some of their characteristics. Austenite leaves its affects and "finger print" in the form of the austenite grain boundary. Shape and size of the austenite grain will determine the rates of transformation through points of nucleation, or "toe holds" for transformations <a href="http://www.cashenblades.com/metallurgy.html#" style="text-decoration: underline;" id="_GPLITA_0" title="Powered by Text-Enhance" name="_GPLITA_0">to begin</a>. And this in turn will affect the formation of new austenite upon reheating to ac1. Steel with larger austenite grains tends to harden more deeply due to the reduction of nucleation points for the diffusion of pearlite to begin. The drawback is that larger grains make steel much more weak and brittle. For bladesmithing the greater of these two evils is the brittleness so large grains and grain growth is to be avoided whenever possible. Austenite grain growth occurs when the steel is heated beyond ac1 and Acm (the point at which the extra cementite is dissolved), and increases with temperature. The larger austenite grains will grow at the expense of the smaller grains. So time at these elevated temperatures should be carefully watched and kept to a minimum. When heating steel to ac1 the shift to gamma iron will allow any pearlite to be dissolved and form new austenite grains. These new grains will be slightly finer and within the previous boundaries due to increased nucleation. As temperature increases the proeutectoid ferrite (if the steel is hypoeutectoid) or proeutectoid cementite (if the steel is hypereutectoid) will be dissolved until ac3 or Acm and there is complete austenite.<br/><br/><br/><br/><br/> <img src="http://www.cashenblades.com/images/info/pearlite.jpg" alt="" title="" height="355" width="360" align="right" border="0"/></p>
<div align="center">Pearlite</div>
<p><br/><br/> When steel that has been heated until carbon is in solution is then allowed to cool slowly that carbon will come out of solution in localized areas of sheet like banding, or lamellae. These lamellae will then create zones of carbon depleted ferrite on either side and this pattern will repeat throughout the prior austenite grains. The lamellae will scatter the light of an optical microscope creating an odd iridescent effect that resembled mother of pearl, hence the name of this steel phase. With the carbon our of solution in this manner pearlitic steel is much softer and becomes more ductile and malleable, however in steel will carbon in excess of .8% the carbide sheets can grow very large and in some undesirable places causing difficulties in machining and embrittlement. For this reason the old standard bladesmith annealing by heating above critical and then slow cooling by insulating may work fine for medium carbon steels, but can be complicated by higher carbon alloys. For this reason, instead of the lamellar method, I use a different annealing that is commonly used in the steel industry for high carbon steel.<br/><br/><br/><br/><br/><br/><br/><br/> <img src="http://www.cashenblades.com/images/info/sphere.jpg" alt="" title="" height="360" width="360" align="left" border="0"/> <br/><br/><br/><br/><br/><br/></p>
<div align="center">Spheroidal Carbide</div>
<p><br/> When steel is heated to temperatures below the critical the carbon is permitted to move but to a much lesser degree than higher temperatures, this causes the carbon to form spheroidal carbides in many fine localized points within the soft ferrite matrix. The heat treating process for this is called spheroidizing and is a very good way to get high carbon steel very soft. The spheroidal carbides offer much less resistance to cutting tools than the sheets of carbide in lamellar pearlite. Also added benefits of this approach to annealing are no affecting of grain size or other issues associated with heavy heating, but the grain and carbide condition must be carefully set up before this with proper normalizing. <br/> <br/> <br/> <br/> <br/> <br/> <img src="http://www.cashenblades.com/images/info/martensite1.jpg" alt="" title="" height="363" width="360" align="right" border="0"/><br/><br/><br/><br/></p>
<div align="center">Martensite</div>
<p><br/> Named for the German metallurgist Adolph Martens, Martensite is the hardened phase of steel that is obtained by cooling Austenite fast enough to trap carbon atoms within the cubic iron matrix distorting it into a body centered tetragonal structure. Since its formation is accomplished by quick cooling, avoiding the formation of pearlite, it is a sheer dependent diffusionless transformation. Free of diffusion processes, it has the same composition as the parent austenite. Under the microscope in cross section it appears acicular, or needle like, but in 3 dimensions is actually either lath or plate in structure. Alloys with less than .6 percent carbon form lath martensite. Alloys with more than 1 percent carbon form plate martensite and alloys with from .6 to 1 percent carbon form mixtures of the two in varying degrees. The temperature at which martensite begins to form in an alloy is given the designation Ms (martensite start). Formation occurs in "packets" with lath martensite, as the crystalline structure begins with single plane forming across the grain with many subsequent branches nucleating from the central one in a parallel "fern' or "feather" like configuration. Plate martensites form in larger plates that have a tendency to approach others at varying angles (irrational habit planes). Points of great stress are created where the plates intersect, causing plate martensite to be more brittle.</p> The Growth of Metallurgytag:travelingwithintheworld.ning.com,2012-01-30:2185477:Topic:1656682012-01-30T02:27:08.040ZDept of PMM Artists & thingshttp://travelingwithintheworld.ning.com/profile/Artistsandthings
<p>By</p>
<p>Alan W. Cramb</p>
<p>Department of Materials Science and Engineering</p>
<p>Carnegie Mellon University</p>
<p>After the seven metals of antiquity: gold, silver, copper, mercury, tin , iron and lead, the next metal to be discovered was Arsenic in the 13th century by Albertus Magnus. Arsenicus (arsenious oxide) when heated with twice its weight of soap became metallic. By 1641 arsenious oxide was being reduced by charcoal. Arsenic is steel gray, very brittle and crystalline; it…</p>
<p>By</p>
<p>Alan W. Cramb</p>
<p>Department of Materials Science and Engineering</p>
<p>Carnegie Mellon University</p>
<p>After the seven metals of antiquity: gold, silver, copper, mercury, tin , iron and lead, the next metal to be discovered was Arsenic in the 13th century by Albertus Magnus. Arsenicus (arsenious oxide) when heated with twice its weight of soap became metallic. By 1641 arsenious oxide was being reduced by charcoal. Arsenic is steel gray, very brittle and crystalline; it tarnishes in air and when heated rapidly forms arsenious oxide with the odor of garlic. Arsenic compounds are poisonous. The symbol As is taken from the latin arsenicum. Arsenic was used in bronzing and improving the sphericity of shot. The most common mineral is Mispickel or Arsenopyrite (FeSAs) from which arsenic sublimes upon heating.</p>
<p>The next metal to be isolated was antimony. Stibium or antimony sulphide was roasted in an iron pot to form antimony. Agricola reported this technique in 1560. Antimony whose name comes from the Greek "anti plus monos"- a metal not found alone, has as its symbol Sb from the latin stibium. It is an extremely brittle flaky metal. Antimony and its compounds are highly toxic. Initial uses were as an alloy for lead as it increased hardness. Stibnite is the most common ore. It was commonly roasted to form the oxide and reduced by carbon.</p>
<p>By 1595,bismuth was produced by reduction of the oxide with carbon , however, it was not until 1753 when bismuth was classified as an element. Zinc was known to the Chinese in 1400; however , it was not until 1738 , when William Champion patented the zinc distillation process, that zinc came into common use. Before Champion's process, zinc, which was imported from China, was known as Indian Tin or Pewter. A Chinese text from 1637 stated the method of production was to heat a mixture of calamine (zinc oxide) and charcoal in an earthenware pot . The zinc was recovered as an incrustation on the inside of the pot. In 1781 zinc was added to liquid copper to make brass. This method of brass manufacture soon became dominant.</p>
<p>One other metal was discovered in the 1500's in Mexico by the Spaniards. This metal was platinum. Although not 100% pure, it was the first metal to be discovered and sourced from the "New World". The property which brought this metal to the prospectors attention was its lack of reactivity with known reagents. Early use of platinum was banned because it was used as a blank for coins which were subsequently gold coated, proving that the early metallurgists understood not only density but also economics. Although, platinum was known to the western world, it was not until the 1800's that platinum became widely used.</p>
<p>Several other metals were isolated during the 1700's. These were Cobalt, Nickel, Manganese, Molybdenum, Tungsten, Tellurium, Beryllium , Chromium, Uranium, Zirconium and Yttrium . Only laboratory specimens were produced and all were reduced by carbon with the exception of tungsten which became the first metal to be reduced by hydrogen.</p>
<p>Therefore, before 1800 there were 12 metals in common use:</p>
<p>Gold</p>
<p>Silver</p>
<p>Copper</p>
<p>Lead</p>
<p>Mercury</p>
<p>Iron</p>
<p>Tin</p>
<p>Platinum</p>
<p>Antimony</p>
<p>Bismuth</p>
<p>Zinc</p>
<p>Arsenic</p>
<p>Before 1805 all metals were reduced by either carbon or hydrogen , however, the majority of the metals once smelted were not pure. Refining of gold, that is the separation of silver from gold, has a very old history. During the second millennium it is clear that an amalgamation process using molten lead was used to separate the metal from crushed quartz. The lead then being cupelled to separate the gold and the silver. Purification was then carried further (but not until the first millennium) by a cementing process where a mixture of the alloy was closely mixed with common salt.The silver reacted, formed a chloride which was soluble and easily rinsed off. The cementation process was used until about 1100 A.D. when other refining processes became popular. One method used sulphur addition to the molten bullion to form silver sulfide which was removed as "black" during gentle beating. Mineral acids were developed by the alchemists. Nitric acid was used to dissolve silver in the 1200's as a purification technique. By the end of the 15th century , Stibium (antimony sulfide) was also used in the cementation process. Generally, a mixture of salt, stibium and sulphur was heated with the gold foil.</p>
<p>Gold plating of silver was very popular and in 1250 Bartholommeus Anglicus gave the following advice:</p>
<p>"And when a plate of gold shall be melded with a plate of silver, or joined there to, it needeth to beware namely of three things, of powder, of winde and of moisture: for if any hereof come between gold and silver, they may not be joined together,then one with another: and therefore it needeth to meddle these two metals together in a full cleane place and quiet and when they be joined in this manner, the joining is inseparable, so that they may not afterward be departed asunder,"</p>
<p>This advice is good today. Amalgamation processes were also popular. The gold was dissolved in mercury. The amalgam was coated onto the piece and then heated to drive off the mercury leaving a gold coated piece. Gold could also be removed by the reverse process (1567).</p>
<p>Before 1807 all metals which had been separated had been reduced by either carbon or hydrogen. The separation of other metals needed the invention of the galvanic cell. Sir Humphrey Davy used the generating pile developed by Volta and demonstrated that water could be decomposed into hydrogen and oxygen . Next he tried a solution containing potash and again gained hydrogen and oxygen. Then he tried a piece of moistened potash which produced at the negative electrode something that burned brightly. His next experiment was decisive, he placed the potash on an insulated platinum dish which was connected to the negative pole of the battery. He then connected the positive pole to the upper surface of the potash and produced small metallic globules. In this manner he produced potassium and sodium.</p>
<p>The Swedish chemist , Berzelius, found that the metals contained in lime and baryta (barium oxide) could also be separated in this way. He used mercury as a cathode which caused the separated metals to dissolve in the mercury. After electrolysis the mercury was distilled away and Calcium and Barium were left behind. Later, Davy produced Strontium by the same technique. By allowing the manufacture of sodium and potassium Davy and Berzelius had opened the door to the reduction of many refractory materials.</p>
<p>In 1817 Cadmium was discovered. Stroymeyer noted that zinc carbonate had a yellowish tinge not attributable to iron. Upon reduction he thought that the alloy contained two metals. The metals were separated by fractional distillation. At 800 C, as cadmium's boiling point is lower than zinc, the cadmium distilled first.</p>
<p>In 1841 Charles Askin developed a method of separating cobalt and nickel when both metals are in solution. Using a quantity of bleaching powder he found that if the quantity of powder was small enough only cobalt oxide was precipitated and separated. The nickel could then be easily precipitated with lime and a source for pure cobalt and nickel was available. Pure cobalt oxide revolutionized the pottery industry as the blues were now available.</p>
<p>Chromium although it had been produced by reduction with carbon was the first metal to be extensively produced using another metal (zinc). Wohler in 1859 melted chromium chloride under a fused salt layer and attracted the chromium with zinc. The resulting zinc chloride dissolved in the fused salt and chromium produced.In 1828, Wohler produced beryllium by reducing beryllium chloride with potassium in a platinum crucible.</p>
<p>Aluminium was first produced by Christian Oersted in 1825. However it was not until 20 years later that significant quantities were produced. Wohler fused anhydrous aluminum chloride with potassium to set free aluminum. Later Ste Claire Deville in 1854 put together a production process using sodium instead of potassium.</p>
<p>The current from Galvanic cells were also used for electroplating. This was first practiced in the 1830's when silver was deposited on baser metals. After silver plating, copper and nickel plating was developed. In the middle of the 18th century it was found that metallic separation could be carried out by the application of galvanic electricity. The current was passed from an anode made of an impure , crude metal into a suitable electrolyte and the pure material plated out onto a resistant cathode. Impurities present in the crude cathode dropped to the bottom of the vessel and formed a sludge.</p>
<p>From this short review of metallurgical developments it can be seen that as the early metallurgists became more sophisticated their ability to discover and separate all the metals grew. However in all of their work it was necessary for all the basic steps to be carried out e.g. the ore had to be identified, separated from gangue, sized, concentrated and reduced in a manner which accomplished a phase separation.</p>
<p>Suggested Reading</p>
<p>L. Aicheson, A History of Metals, 2 Vols., New York, Interscience, 1960</p>
<p>F. Habashi, Principles of Extractive Metallurgy, Vol. 1, Chpt. 1, Gordon and Breach, Science Publishers, Inc., New York.</p>
<p>The Making, Shaping and Treating of Steel, U.S.S..</p>
<p>Copper Development Association, Copper Through the Ages, London, 1960.</p>
<p>Table 1: METALS DISCOVERED IN 18TH CENTURY</p>
<p>1735 Cobalt</p>
<p>1751 Nickel</p>
<p>1774 Manganese</p>
<p>1781 Molybdenum</p>
<p>1782 Tellurium</p>
<p>1783 Tungsten</p>
<p>1789 Uranium</p>
<p>1789 Zirconium</p>
<p>1791 Titanium</p>
<p>1794 Yttrium</p>
<p>1797 Berylium</p>
<p>1797 Chromium</p> A Short History of Metalstag:travelingwithintheworld.ning.com,2012-01-30:2185477:Topic:1657352012-01-30T02:23:20.082ZDept of PMM Artists & thingshttp://travelingwithintheworld.ning.com/profile/Artistsandthings
<p>By</p>
<p>Alan W. Cramb</p>
<p>Department of Materials Science and Engineering</p>
<p>Carnegie Mellon University</p>
<p>Process Metallurgy is one of the oldest applied sciences. Its history can be traced back to 6000 BC. Admittedly, its form at that time was rudimentary, but, to gain a perspective in Process Metallurgy, it is worthwhile to spend a little time studying the initiation of mankind's association with metals. Currently there are 86 known metals. Before the 19th century only 24 of…</p>
<p>By</p>
<p>Alan W. Cramb</p>
<p>Department of Materials Science and Engineering</p>
<p>Carnegie Mellon University</p>
<p>Process Metallurgy is one of the oldest applied sciences. Its history can be traced back to 6000 BC. Admittedly, its form at that time was rudimentary, but, to gain a perspective in Process Metallurgy, it is worthwhile to spend a little time studying the initiation of mankind's association with metals. Currently there are 86 known metals. Before the 19th century only 24 of these metals had been discovered and, of these 24 metals, 12 were discovered in the 18th century. Therefore, from the discovery of the first metals - gold and copper until the end of the 17th century, some 7700 years, only 12 metals were known. Four of these metals, arsenic, antimony , zinc and bismuth , were discovered in the thirteenth and fourteenth centuries, while platinum was discovered in the 16th century. The other seven metals, known as the Metals of Antiquity, were the metals upon which civilisation was based. These seven metals were:</p>
<p></p>
<p>(1) Gold (ca) 6000BC</p>
<p>(2) Copper,(ca) 4200BC</p>
<p>(3) Silver,(ca) 4000BC</p>
<p>(4) Lead, (ca) 3500BC</p>
<p>(5) Tin, (ca) 1750BC</p>
<p>(6) Iron,smelted, (ca) 1500BC</p>
<p>(7) Mercury, (ca) 750BC</p>
<p>These metals were known to the Mesopotamians, Egyptians, Greeks and the Romans. Of the seven metals, five can be found in their native states, e.g., gold, silver, copper, iron (from meteors) and mercury. However, the occurrence of these metals was not abundant and the first two metals to be used widely were gold and copper.</p> A Brief Dissertation on Metals By: Frederich Von Teufeltag:travelingwithintheworld.ning.com,2011-02-23:2185477:Topic:1048112011-02-23T16:27:41.138ZDept of PMM Artists & thingshttp://travelingwithintheworld.ning.com/profile/Artistsandthings
<p>Periodically, someone will ask the gathered group of armourers, "what steel should I use?" or "what's the difference between these two metals?" If you are new to the craft, or just in the process of widening your knowledge, here is a brief dissertation on metals.</p>
<p>Now, metals can be broken down into two groups, ferrous and non-ferrous. That's basically iron based alloys, and everything else.</p>
<p>Iron is just that, iron ore. If carbon is added to iron, it becomes 'steel'. Steel…</p>
<p>Periodically, someone will ask the gathered group of armourers, "what steel should I use?" or "what's the difference between these two metals?" If you are new to the craft, or just in the process of widening your knowledge, here is a brief dissertation on metals.</p>
<p>Now, metals can be broken down into two groups, ferrous and non-ferrous. That's basically iron based alloys, and everything else.</p>
<p>Iron is just that, iron ore. If carbon is added to iron, it becomes 'steel'. Steel doesn't actually become hardenable until about .4 of a percent carbon is added. That isn't that much, if you think about it, not quite 20 grams of carbon to every pound of steel. Chromium is added to make steel 'stainless', usually 12% to 20%. There are other things used to improve the workability of steel, such as Manganese, Vanadium, Molybdenum, Tungsten and Nickel. These are added in various quantities to increase certain characteristics of the steel such as strength and hardness.</p>
<p>If you are an armourer, the benefits that these alloys give you is minimal. If you are a knife or sword smith, then the alloy becomes important, because a knife doesn't need to be simply tough and dent resistant, but also hold an edge and resist violent shocks as well.</p>
<p>The primary steels that most armourers will use are of the 10xx series. This is plain unalloyed steel with a varying amount of carbon (the xx refers to the amount of carbon in the steel.) Occasionally, an armourer will use a 'stainless' steel. What this steel <i>actually</i> is, will depend on where they got the steel from. The only thing that is assured, is that the chromium content of the steel is fairly high, typically over 12%. This has two effects on the steel. First, it is rust <i>resistant</i> (not rust proof). Second, when chromium is added the steel becomes very resistant to working, becomes 'springy' and resistant to dishing and raising. It also has a much higher hot working temperature (forging temperature). From personal experience, I have found that stainless steels seem to react like a carbon steel that is 2 to 4 gauges thicker, i.e. a 16 gauge stainless steel elbow cop is as difficult to dish as a plain carbon steel elbow cop that was 12 to 14 gauge in thickness. (Using a heavy hammer becomes a blessing at this point.)</p>
<p>One point to bring up here is the difference between 'hot rolled steel' and 'cold rolled steel'. The hot or cold refers to the temperature of the steel during its final pass through the rollers at the steel mill. A 'hot' rolled steel will come out of the rollers "annealed" (soft), while a 'cold' rolled steel will come out "work hardened." Many armourers will advertise that they only use 'cold rolled steel'. This might make a difference on pieces that are not welded or heated in any way, but if the piece <i>is</i> heated or welded, it becomes annealed, and therefore no better than a hot rolled steel.</p>
<p>To understand this whole process, it's good to visualize the steel as a liquid in its solid form. The liquid (iron) has been mixed together with carbon and then frozen. What the carbon does, is bind together with the iron to make a mix of iron and iron carbide. At forging temperature, the mix is very even and is called 'Austenite.' When the steel is cooled rapidly (quenched) the iron and carbon freeze in place and make a coarse, uneven matrix of iron and large needle like crystals of iron carbide . This matrix is called 'Martensite.' The crystalline structure is fairly large and coarse, making the steel very hard, but also very fragile. When the steel is warmed to a medium temperature (400 to 650 degrees), the crystals are refined to a smaller size, and stresses within the metal are relieved. This is tempering and ends up in an even distribution of carbides with in the iron. Annealing (heating the steel, then letting it cool very slowly) removes all the strength from this careful matrix and make steel soft.</p>
<p>The other material that armourers use is aluminum, usually either 'street sign' aluminum, or T6061. This aluminum has the advantage of being very lightweight, and has been tempered to a fair hardness (compared to something like brass or bronze). Its down side is that it can be expensive and difficult to work. The thing that must be remembered when working with aluminum is that it work hardens very quickly, and will become brittle. One must be always on the lookout for cracking and chipping when working with aluminum.</p>
<p>For armour, remember that most armourers don't quench and temper their stuff, so the amount of hardenability of the steel comes more from work hardening (refining the crystal size and distribution through working the steel.)</p>
<p>For weapons, the criteria for choosing a steel is very different. A sword or knife needs strength, flexibility, shock resistance and edge holding ability. A 10xx series steel is an acceptable steel for most purposes, but it can be improved upon. Adding chromium to sword steels is not a good thing, as it reduces flexibility, and increases brittleness, but in a knife those things aren't as vital.</p>
<p>The most common steels in use at the moment for swords are probably 5160, W1 and L6. 5160 is a 'spring' steel that has .60 percent carbon, .8 percent chromium, and .8 percent manganese. This makes a tough, shock resistant steel. W1 is a like 5160, but with out chromium and manganese. L6 is essentially much like 5160 but with the addition of nickel and vanadium. Nickel and vanadium improves its hardenability and shock resistance. Which is better? Your choice, I don't know if it will make much of a difference for most people not involved in 'live steel combat' or japanese tameshigiri (cutting) practice. If you never use it as a sword, and only display it on a wall, it might as well be made from aluminum.</p>
<p>When deciding on a material, try to remember the application that the end product will be put through. Then choose whatever material will be best suited for that use.</p>
<p>I can recommend the following books to help you in your search for smithing expertise.</p>
<ul>
<li>Jim Hrisoulas' books are invaluable to anyone who is interested in making knives/swords and steel in general.<ul>
<li>"The Complete Bladesmith: Forging Your Way to Perfection"; Paladin Press.</li>
<li>"Master Bladesmith: Advanced Studies in Steel"; Paladin Press</li>
<li>"Pattern Welded Blade"; Paladin Press</li>
</ul>
</li>
<li>Kapp, Leon, et al; "The Craft of the Japanese Sword"</li>
<li>Boye, David; Step-By-Step Knifemaking; Rodale Press</li>
<li>McCreight, Tim; Custom Knifemaking : 10 Projects from a Master Craftsman"; Stackpole Books</li>
<li>Bergman, Bo; "Knifemaking: A Complete Guide to Crafting Knives, Handles & Sheaths"; Lark Books</li>
<li>Fowler, Ed; "Ed Fowler's Knife Talk : The Art & Science of Knifemaking"; Krause Publications</li>
<li>Barney, Richard; "How to Make Knives"; Krause Publications</li>
<li>McCreight, Tim; "The Complete Metalsmith: An Illustrated Handbook"; Davis Publications.</li>
<li>Seitz, William; "Silversmithing"; Chilton Books</li>
<li>Gooden, Robert; "Silversmithing"</li>
<li>Andrews, Jack; "Edge of the Anvil"; Rodale Press</li>
<li>Blanford, Percy; "Practical Blacksmithing and Metalworking"; Tab Books</li>
<li>Bealer, Alex; "The Art of Blacksmithing"</li>
</ul>
<p>Unfortunately, there aren't any books that can similarly targeted to helping the novice armourer. You will have to do what every present-day armourer does, pore over thousands of photos of armour, visit museums and study the armour on display, and network with other armourers to share your knowledge.</p>
<p>The only book that attempts to cover the subject, "The Armourer and His Craft: From the XIth to the XVth Century by Charles Foulkes", is suspect and contains many fallacies. It was written by someone who, while he had great experience with armours in museums, had little to no experience in actually making the armour. It is worthwhile for its many details of measurement, and photos and engravings, but take the information held within with a grain of salt.</p>
<p>For armouring, you will find that the same techniques are used in silversmithing, blacksmithing and even auto body work (take a browse through Sheet Metal Handbook by Ron Fournier, HP Books.) If you take what you can from those methods and adapt it to armouring you'll be on the right track.</p>
<p>Good luck!</p>
<p>Frederich Von Teufel</p> Metalworking and the Smithtag:travelingwithintheworld.ning.com,2011-02-03:2185477:Topic:982192011-02-03T19:09:03.872ZDept of PMM Artists & thingshttp://travelingwithintheworld.ning.com/profile/Artistsandthings
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<tbody><tr><td valign="top"><font face="Times New Roman">Iron is found in iron ore (rock) and the first stage of ironmaking is to extract the metal from the ore. This is best done at the place where the iron ore is dug out of the ground, otherwise a lot of waste material has to be carried about. It is thought that iron was brought to Jorvik (York) as ingots (bars of iron) already extracted from the ore. Some probably came from…</font></td>
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<tbody><tr><td valign="top"><font face="Times New Roman">Iron is found in iron ore (rock) and the first stage of ironmaking is to extract the metal from the ore. This is best done at the place where the iron ore is dug out of the ground, otherwise a lot of waste material has to be carried about. It is thought that iron was brought to Jorvik (York) as ingots (bars of iron) already extracted from the ore. Some probably came from <a href="http://www.viking.no/e/england/york/jorvik_regional_map.html">the Lake District, the North York Moors</a>; some came <a href="http://www.viking.no/e/england/york/map_jorvik_trade_abroad.html">from Scandinavia</a> where richer ores are to be found. Once in Jorvik, the ingots could be heated up again by smiths who could then forge (hammer) them into the shapes they wanted. Or it could be melted right down again and cast (poured) into ready-shaped stone or clay moulds. After casting, some more work could be done on the object to finish it - filing, re-heating and forging, polishing and perhaps putting some sort of decoration on.</font><p><font face="Times New Roman">Steel is iron which has been combined with fairly pure carbon and it is much better than iron for keeping a sharp edge. But good steel was difficult to make in the Viking Age and probably only small quantities could be made at any one time.</font></p>
<p><font face="Times New Roman">Steel had to be used sparingly, so it was used for the cutting edges and points of iron tools and weapons. An expensive and very strong knife, sword or axe could be made by forging alternate layers of iron and steel together. To decorate iron items, strips of steel, copper or precious metals could be inlaid in them during forging.</font></p>
<h2><font face="Times New Roman"><font face="Arial, Helvetica" color="#7E0505">Some metalworking techniques and terms</font></font></h2>
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<dt><font face="Times New Roman"><strong>forging</strong></font></dt>
<dd><font face="Times New Roman">Heating metal in a furnace or hearth until it is red- or white-hot, then hammering, bending and punching it into shape.</font></dd>
<dt><font face="Times New Roman"><strong>casting</strong></font></dt>
<dd><font face="Times New Roman">Heating metal until it is liquid, then pouring it into ready-shaped moulds (made of stone, clay or sand) and allowing it to cool and set.</font></dd>
<dt><font face="Times New Roman"><strong>rivetting</strong></font></dt>
<dd><font face="Times New Roman">Fastening two or more pieces of material together. Matching holes are made in the pieces, then a rivet (peg) is pushed through the holes and hammered over tightly at each side to form 'mushroom' heads which clamp the pieces together. If the pieces being fastened together are metal, then the rivet is heated up and as it cools and contracts it tightens. Soft metal rivets can be used for 'cold' rivetting where heat would be undesirable (such as rivetting bone or wooden handle strips to a knife blade).</font></dd>
<dt><font face="Times New Roman"><strong>welding</strong></font></dt>
<dd><font face="Times New Roman">A process for bonding metal pieces by heating them to red or white heat then hammering them together so they fuse into one. Pattern-welding was done by welding strips of a different metal to the surface of, for example, a blade.</font></dd>
<dt><font face="Times New Roman"><strong>furnace</strong></font></dt>
<dd><font face="Times New Roman">An enclosed oven-like structure, made of stone or clay (or clay-lined stone) in which iron can be extracted from its ore. The ore would be placed in the furnace on a bed of wood or charcoal and the chamber brought to a high temperature using bellows, blowing into the furnace through a nozzle (tuyère). A simple, primitive furnace may have no bellows but rely on an opening facing the wind but it would be impossible to reach really high temperatures this way. A small opening in the top of the furnace allows smoke to escape. The process is known as smelting and the smelted metal runs out of the ore and either gathers at the base of the furnace or is run off into moulds to set as ingots.</font></dd>
<dt><font face="Times New Roman"><strong>hearth</strong></font></dt>
<dd><font face="Times New Roman">An open furnace, used by smiths to re-heat ingots and metal items ready for shaping. Hearth temperature would be raised by the use of bellows. The normal fuel would be charcoal.</font></dd>
<dt><font face="Times New Roman"><strong>bellows</strong></font></dt>
<dd><font face="Times New Roman">A device for directing a stream of air at fuel in a furnace or hearth, so that it has a rich supply of oxygen. This makes the burning fierce for the high temperatures needed for smelting ore or working metal. A simple bellows might be a hide or skin bag with a fine outlet nozzle of metal, wood or bone. Squeezing and pulling the bag would produce the stream of air which is directed at the fuel. It would normally be the job of an ironmaker's or blacksmith's assistant, or an apprentice, to do the pumping.</font></dd>
<dt><font face="Times New Roman"><strong>anvil</strong></font></dt>
<dd><font face="Times New Roman">A hard block on which the smith forges, bends, stretches, welds and punches metal. A strong flat stone would serve the purpose - or even a tree stump with a flat stone or flat metal plate on top. The best anvil, though, is one made entirely of cast iron, with a smooth, flat surface on top, a tapering 'beak' at one end, and some holes for punching through. A large all-iron anvil would be difficult to make in the Viking Age because of the great mass of cast iron needed at one time. A small anvil was found by archaeologists at the Jorvik site.</font></dd>
<dt><font face="Times New Roman"><strong>soldering</strong></font></dt>
<dd><font face="Times New Roman">Bonding light or soft metal together with molten tin, lead, silver or gold, or alloys of these metals.</font></dd>
<dt><font face="Times New Roman"><strong>brazing</strong></font></dt>
<dd><font face="Times New Roman">Bonding light or soft metal together with molten brass or copper alloys.</font></dd>
<dt><font face="Times New Roman"><strong>blacksmith</strong></font></dt>
<dd><font face="Times New Roman">A craftsman who works mainly with iron and steel. Often called simply a 'smith' and in the Viking Age a smith would often be an all-round metalworker, working with copper, bronze, lead, tin, and precious metals, as well as iron and steel. In later times, each type of metal had its own specialist craftsmen, such as silversmiths, tinsmiths, and so on. In Jorvik, smiths may have been involved in the <a href="http://www.viking.no/e/england/york/minting_coins_in_jordvik.html">minting of coins</a> and making and repairing jewellery.</font></dd>
<dt><font face="Times New Roman"><strong>farrier</strong></font></dt>
<dd><font face="Times New Roman">One who makes and fits shoes to horses. Farriery was normally part of a blacksmith's work.</font></dd>
<dt><font face="Times New Roman"><strong>alloy</strong></font></dt>
<dd><font face="Times New Roman">A mixture of two or more metals. Bronze, for example, is an alloy of copper and tin.</font></dd>
<dt><font face="Times New Roman"><strong>plating</strong></font></dt>
<dd><font face="Times New Roman">Giving one metal a thin coating of another metal to improve its appearance, for decoration, or to protect the core metal against corrosion. Plating processes in the Viking Age would probably have been crude and may simply have involved briefly dipping the core object in the molten plating metal, or melting the plating metal over the object. Tin, tin-lead alloy and copper alloy plated items have been found at Jorvik.</font></dd>
<dt><font face="Times New Roman"><strong>quenching</strong></font></dt>
<dd><font face="Times New Roman">Plunging hot metal into water after it has been forged to shape. It is important to judge exactly the right time to do this. If it is done too soon the metal may become brittle and shatter easily; but leave it too long to quench and the metal may be too soft to sharpen into an edge. Sometimes, it is necessary to re-heat metal to the correct temperature before quenching it. The smith's skill with quenching iron/steel is in watching the colour change as it cools from near-white, to bright red, through to cherry red, then very dark red. Quenching takes place when the colour is judged correct for the purpose of the item, such as cutting, chiselling, striking, or bending. Steel can be specially quenched (tempered) by plunging it into oil instead of water; this makes it slightly springy and able to bend in a way that would shatter iron or untempered steel.</font><p><font face="Times New Roman">Magic !</font></p>
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<p><font face="Times New Roman"><font face="Times New Roman">The skills and processes of working metal (especially iron) were a mystery to most people in ancient and Viking times and were thought by superstitious people to be magical. 'Magical' iron and skilled smiths feature in the myths and legends of the Anglo-Saxon, Scandinavian and other Germanic peoples. A well-known mythical figure is <a href="http://viking.no/kirkgate/weyland.htm">Weyland the Smith</a>. The iron horseshoe - one of the typical products of the smith - is still regarded as a 'magical' symbol today and is hung on walls and doors to bring good luck (but only if the curved part is at the bottom, otherwise the luck 'falls out' !).</font></font></p>
<p><font face="Times New Roman"><font face="Times New Roman">Smiths probably added to the sense of mystery by carefully guarding the secrets of their craft, revealing them only to their chosen apprentices, who would often be their own sons or other members of the family. This made the smith an important figure in the community and every village probably had its own smith, or family of smiths, which is why the <a href="http://www.viking.no/e/england/york/smith.html">family name Smith</a> is the most common one in Great Britain, with equivalents in many other countries. This shows how important was the smith and his work in many parts of the world. Rulers and important noblemen would often have their own personal smith. A Viking Age trading town like Jorvik (York) would have had work for several smiths at any one time.</font></font></p>
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</table> http://kodumanal.blogspot.com/2008_07_01_archive.htmltag:travelingwithintheworld.ning.com,2010-09-15:2185477:Topic:591442010-09-15T16:02:53.555ZRev. Allen M. Drago ~ Travelerhttp://travelingwithintheworld.ning.com/profile/Traveler
<h3 class="post-title entry-title"><a href="http://kodumanal.blogspot.com/2008/07/genesis-of-ukku-insights-from.html">Genesis of ‘ukku’: Insights from megalithic ferrous metallurgy, high-tin bronzes and</a></h3>
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Genesis of ‘ukku’: Insights from megalithic ferrous metallurgy, high-tin bronzes and<br></br>crafts ‘Wootz’ is known to be an anglicised version of ‘ukku’, the word for steel in south India. The term ‘ukku’ may derive from ‘uruku’, used to describe fused…
<h3 class="post-title entry-title"><a href="http://kodumanal.blogspot.com/2008/07/genesis-of-ukku-insights-from.html">Genesis of ‘ukku’: Insights from megalithic ferrous metallurgy, high-tin bronzes and</a>
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Genesis of ‘ukku’: Insights from megalithic ferrous metallurgy, high-tin bronzes and<br/>crafts ‘Wootz’ is known to be an anglicised version of ‘ukku’, the word for steel in south India. The term ‘ukku’ may derive from ‘uruku’, used to describe fused or melted metal in Tamil Sangam literature dated broadly from about the 5th century BC to 5th century AD, while accounts of the Greek Zosimos of the early Christian era suggests that the Indians used crucible processes to make metal for swords, i.e. steel. Pliny’s ‘Natural History’ talks of iron from the Seres which may refer to the ancient south Indian kingdom of the Cheras who are referred to in Sangam texts. While Thelma Lowe, most of all, and others have made crucial studies on the mechanisms of late medieval<br/>Deccani wootz production, there still remains much to be investigated and clearly established concerning the antiquity of wootz steel in India and on the identification of ancient artefacts of wootz. It is significant that there are a couple of analyses reported in early excavation reports from some megalithic sites in southern India of iron artefacts with 1-2% carbon (for eg. two javelins from megalithic Andhra Pradesh mentioned in Sundara 1999); however further investigations with micro-structural evidence may be required to ascertain if these can be taken as conclusive evidence for wootz steel. Investigations by the author on a crucible fragment from the megalithic site of Kodumanal (3rd century BC) excavated by K. Rajan, Tamil University, found in an iron smelting hearth showed it to be iron-rich without any other significant metal, which did not rule out the fact that it could belong to some kind of ferrous process although as yet no clear evidence of metallic remnants could be found in the crucible (Srinivasan and Griffiths 1997).<br/>Significantly, the author has identified from surface surveys three previously unknown sites for crucible steel production in southern India (ibid.). Crucibles from one of these sites, Mel-siruvalur in Tamil Nadu shows clear evidence for the production of a hyper-eutectoid (1.3% C) steel, i.e. a high-carbon steel, probably even by molten carburisation processes at high-temperatures (Srinivasan 1994, Srinivasan and Griffiths 1997). More significantly, the site shows signs of megalithic occupation in the vicinity as independently verified by Sasisekaran (2002) while the author found numerous remains of what appeared to be legs of megalithic sarcophagi in a dried up canal near<br/>the dump. (The megalithic period in southern India ranges in different places from the early 1st millennium BC to early centuries AD). This site is being further investigated by the author. Other aspects of megalithic iron production to be touched upon include the iron smelting furnace excavated at Naikund, from the Vidharbha megaliths of Maharashtra.<br/>As background, this chapter would also briefly explore whether there are technological parameters within the context of peninsular megaliths which could have supported more advanced metallurgical skills. Previously the Indian subcontinent had not been associated with a more sophisticated bronze working tradition. However, metallurgical investigations by the author established for the first time the use of specialized alloys known as hightin beta bronzes (which are quenched binary copper-tin alloys bronzes of around 23% tin) to make vessels going back at least to the iron age burials megaliths of the early first millennium BC of the Indian subcontinent which rank amongst the early such alloys known in the world, and which are still made in parts of India such as Kerala by similar processes as reported in Srinivasan (1994b, 1997, 1998a) and in papers written by the author with Ian Glover while at Institute of Archaeology, London (Srinivasan and Glover 1995, 1997). High-tin beta bronzes generally do not seem to have been in vogue in Europe, and indeed the Greek Nearchus (4th century BC) mentions that Indians used golden vessels which shattered when dropped which may be interpreted as high-tin bronze, as suggested by Rajpitak and Seeley (1979). What is significant is that the processes of quenching high-tin bronze indicates a general familiarity with heat treatment processes in the megalithic period that could have extended to the knowledge of iron and steel metallurgy. Other evidence for skilled metallurgical activity comes from evidence suggesting that the deepest old gold mine in the world comes from Hutti in Karnataka with carbon dates from timber collected from a depth of about 600 feet from a mine going back to the mid 1st millennium BC<br/>(Radhakrishna and Curtis 1991).