Metallic sword and knife-making doubtless began when ancient man discovered little green stones on the ground which, when heated sufficiently, yielded copper. This liquid metal then was poured into molds to form axes and knives. These tools were soft, but could be work-hardened by hammering.
Later, these early blacksmiths learned how to alloy tin with copper to make bronze and with zinc to make brass. Both these alloys produced weapons of superior strength and hardness. But there was a far better metal on the horizon.
Iron is one of the most useful metals known to man. It is also one of the most common elements on the planet. In its pure state iron is only slightly harder than copper. But iron is a reactive metal and will combine with many other elements. With the addition of other elements, the properties of iron change drastically. Rarely is iron found that does not have some impurities mixed in with it. Of all the impurities, none is quite so important as carbon. But I get ahead of myself.
No one knows who first discovered iron, or where. In the past it was believed that the Hittites were the first, but that is being challenged as more and more information becomes available. But at the time of this writing, the first makers and users of iron are not known.
More than likely the discovery was an offshoot of the bronze industry. It is quite likely that iron was discovered while mining for tin and copper. Probably this new metal was initially discarded and considered to be just trash. It was possible that it took quite a while for anyone to pay any attention to the material. However, once its abilities were realized, it quickly supplanted bronze as the ideal metal for swords and other weapons.
When you compare the different properties of bronze and iron you can see that it took a great leap to make iron into something useful. Bronze can be cast easily; it can be annealed by heating it up and plunging it into cold water, and thin sheets can be easily worked with a hammer. Iron behaves differently. While it will work harden and thus crack under the stress of cold forging, it has to be heated to be annealed, and then must be cooled very slowly. If it were quench-hardened, as they would do with bronze, it would not soften. If by some chance there were some carbon present, it might get very hard. In short, its behavior was quite different than bronze or copper.
But don't think that once iron was discovered bronze was dropped immediately. Far from it. Just as bronze weapons coexisted with Stone Age ones, so too did iron weapons coexist with bronze ones. Bronze continued to be important in the accoutrements, fittings, guards, pommels, etc., not to mention that maces could still be made from bronze. Even today, brass is still used for modern gun cartridge cases.
Although it took a great deal of time, someone finally figured out that iron could be quite useful, and then iron weapons began to appear. The Iron Age is generally considered to date from about 1400 BC. But this is a date used more for convenience than for anything else. We are already aware that copper was discovered a lot sooner than was thought, and that might be true for iron as well.
The Hittites are frequently given the credit for the discovery of iron, and many believe that the brief Hittite Empire was created by their mighty iron weapons. This is highly doubtful. First, there is no direct evidence that the Hittites used iron in abundance. Second, early iron swords were not much better than their bronze counterparts. Although lighter than bronze swords, they would bend just as easily. It probably took some time for methods to be discovered that yielded a steely iron. In the clash of armies it is quite doubtful that this small advantage would have been sufficient to insure victory and conquest. But it is undeniable that at about this time iron weapons and artifacts begin to appear.
You also have the very likely scenario that the discoverers did not run out and share the information with their neighbors. Undoubtedly the first iron weapons were more curiosities than decidedly better weapons. But in the forging of the blades under heat, some of them absorbed some carbon, and thus came out much tougher than bronze.
Man's nature has not changed in a few thousand years, and when the ancients learned their smiths could make a better blade, they tried to keep it a secret and sell their iron weapons at a premium. After all, the swords were stronger, tougher, lighter, and could be made longer, and, it was felt, be more effective.
It is human nature to keep your foe at a distance if possible. It is widely believed that a longer sword can give you an advantage. (This is only partially true. History shows us that a shorter weapon, used properly, is better than a long one. Consider the Greek phalanx and its twelve-foot-long spears versus the Roman short sword, the short Zulu assegai battling the traditional long African throwing spear, the Spanish sword-and-buckler men against the Swiss pikemen, and even the long rapier against the small sword.) Since the iron sword was a better product, why not get top dollar for it? Although this is just supposition on my part, I have a strong feeling this is what happened.
Restricting the flow of knowledge can only last so long, and in the end the knowledge of iron working spread over most of the world. Although the knowledge of how to smelt the iron and forge blades was pretty common, the ability to make fine swords was not.
There were many "secrets": secret formulas for smelting the iron, secret formulas for forging, and above all, the secret of properly tempering the blade. Smiths all over the world were pretty successful at restricting this knowledge. There was also a lot of mystery to this art, real and imagined. This "mystery" coupled with "the grass is always greener" concept, led to the legends of Toledo, Damascus, Japanese, and Persian swords, and the fabled Indian wootz steel (of which more below).
In a pre-industrial society, the ability to work iron and produce weapons and tools was considered almost magical, and its practitioners were linked to the gods themselves. Although the degree of reverence varied from culture to culture, the blacksmith was a powerful figure, and the blacksmith who produced weapons was even more important. This was true in many societies. Even the practical Romans had Vulcan, the crippled smith of the gods. Indeed, this crippling of the smith may have had some basis in fact. Both the Norse god Weyland and the Roman Vulcan were lame. Obviously this could be simply borrowing from one religion to another, and I am certainly not an expert on mythology. Certainly it is a good way to keep a good smith from running away. But we can read, and see, the importance of the smith in early societies. In Japan, Persia, China, Europe, and even in tribal Africa, the smith was of great importance and highly valued.
It is easy to see how this can happen. Consider taking a lump of metal and changing it into a shining sword blade that is capable of cutting through flesh and bone, and even mail. The whole process can appear magical! Since nothing was known of chemistry or metallurgy, even the practitioners themselves could think of it as magic!
Let me add something here on a personal level. I do not believe in magic. I am a hard core realist, and might best be described as a pragmatic empiricist. Having said that I am also forced to admit to having witnessed things I simply do not understand.
I have seen Jim Fikes, a blacksmith living in Jasper, Alabama, at this time, forge and temper a knife; while others, using the same steel and methods, do the same thing, at the same time. Then testing time comes around. Jim's knife holds an edge much longer, and can be made sharper, than any of the others. This is not hearsay, but it is true, as I was doing the cutting. I made the effort and cut the material as identically as I could, and the results were amazing. I still don't believe in magical swords, but I can be persuaded that there could have been knives and swords that were amazing.
There was one important reason that allowed this "mystery" of making a sword or knife to continue and flourish. The reason was very simple. The makers themselves did not know why the swords they produced were good, mediocre and a few really bad. These last they threw back into the pot to be re-melted and re-forged. What they did know was that if they used ore from a specific place, and did certain things by rote, taking a specified time to do it, and in a certain manner, they frequently came up with a good sword blade. And rarely, a truly superb sword blade appeared. But they did not know why.
The real secret to this was simply carbon content in the iron. But since the science of chemistry and metallurgy had not yet been developed, no one knew it. The average person is quite surprised to learn how late it actually was before the impurity, carbon, was proved to be what turned iron into steel. Some recent discoveries in England have shown that very high quality steel was produced in England in the "Dark Ages" (circa 1476–1000 AD). Hamwic was a Saxon port that is under Southampton. Much of it has now been excavated, and a very interesting discovery was made. Several blooms of very high quality steel were found, plus several knives with high quality steel edges. These blooms are homogenous steel, with about two per cent carbon. Properly forged, this could produce exceptional quality blades.
Shortly before this discovery, another one equally fascinating was announced. It seems that a monastery, abandoned when Henry VIII split from the Catholic Church, was also a metal producing factory. This is not unusual in itself. But what is unusual, is that the process they used was identical to the Bessemer process that was invented by Sir Henry Bessemer in the 19th century, and was in use in manufacturing until quite recently.
In 1740, Benjamin Huntsman, a maker of watch springs, found that he could produce much superior steel by melting the steel, allowing the slag to rise to the surface, and then skimming it off. This is much the same technique as was used in producing Wootz steel of India. But carbon wasn't discovered until 1774 by Swedish metallurgist Sven Rinman. In 1786 French chemist Guyton de Morveau showed that the substance isolated by Rinman was carbon, introduced into the iron that turned the iron into steel.
As early as 1540 A.D. an Italian had suggested that steel was the "pure" form of iron, and to achieve this purity the iron was heated up and charcoal, leather, and other such substances added to help burn out the impurities. Since charcoal and leather both contain carbon, he was on the right track, but going in the wrong direction. It was the impurities—sulfur, phosphorus, nitrogen, hydrogen, total oxygen, and sometimes carbon—that frustrated steel production. Modern steelmakers grapple with these impurities today, but with a clear understanding of what they are fighting. The ancient blacksmith could only fall back on empirical knowledge gained from trial and error.
FROM IRON TO STEEL
Let us take a look at iron and what it can and cannot do. Hollywood, popular fiction, and our own wishful thinking have given to swords properties and abilities that simply do not exist in the real world. Martial arts movies have the hero jumping straight up for twelve feet, and sword films depict blades cutting down large trees, shearing through metal and stone with ease, hitting other blades edge to edge, and never showing a scratch.
Iron is malleable and not too heavy. It can be worked cold, and in thin sheets can be made to take on all sorts of shapes (witness plate armor). [Figure: Photo of a sample of Peter Fuller's modern reproduction armor] Iron is chemically quite active, and will combine readily with many substances. When heated to a cherry red it becomes plastic and can be shaped easily. Work hardening will add a small amount of toughness to iron. But if it is hammered cold too much, it will begin to crack, and even when work hardened it will not have a great deal of toughness. If you add carbon to the iron, the crystalline structure changes. And so do the properties of the metal.
Now this certainly isn't a book on metallurgy, but understanding the basic material that is used to make a sword, and its properties, is important to understanding the weapon, and how it was, and was not, used.
Carbon is the principal alloying element in the manufacture of knives and swords. Although other elements can be added, and will produce some minor changes, it is carbon that makes the most difference. Today we can add chromium and produce stainless steel, add various other trace elements like molybdenum and vanadium, and produce tougher, stronger and better blades. Some of these trace elements were in the various legendary ores, and they produced swords that were better (forging and tempering being equal) than other blades made from bog iron ore or ore with none of the valuable trace elements.
Iron that contains .05 per cent to .20 per cent carbon is considered low carbon steel, and is little better than iron. At best it can be called a "steely iron." Although better than bronze, it does not make a good sword. Medium carbon steels, containing up to .70 per cent, make a good blade. It can be tempered and, although it will not harden to the same degree as high carbon steel, it will harden and take an edge. The best swords are made from high carbon steel, with a carbon range of up to 1.00 per cent. Any higher than this and the carbon shows a strong tendency to make the blade entirely too hard, and subject to easy breakage. (Understand that these figures apply to swords made prior to the 20th century. Modern alloys can make very good sword blades without the same amount of carbon.)
But carbon content alone does not make a good sword. Heat treating, or tempering, is the most important factor. You can have a sword with a medium carbon blade, and one with a high carbon blade, but if the one with the high carbon blade is not tempered properly, it will be inferior to the other. The tempering process was another area that allowed for "secrets." Water is an excellent cooling medium, but it has one problem. Unless the water is highly agitated, it will immediately steam and create a barrier that will delay the cooling process, and you get uneven cooling. This is particularly true for a large object like a sword. This is why running water was used, and why a fall of water was preferred. But fresh water isn't the only medium, brine is very good, as well as oil. All of these make good tempering mediums.
One quenching medium that was not used was a slave, into whom the red hot sword was supposedly thrust to gain some occult property. This is one of the more popular and ridiculous myths that permeate this field. Aside from the moral considerations that our ancestors did, and did not, have, it simply wouldn't work anyway. The human body simply could not remove heat quickly enough to make an effective tempering medium. Nor could it be done in a uniform manner. It sounds good and romantic and magical, but it simply isn't true.
THE FORGING PROCESS
The forging process was usually started with a "cake" of steel. This was a piece of steel about two pounds in weight and was usually obtained through trade. A swordmaker was lucky if he lived close enough to a good source of metal. But this usually wasn't the case.
The steel was heated to a cherry red and then pounded into a bar. This process was repeated several times, and eventually it was shaped into the sword blade. The Japanese had a process whereby they would take the carbon containing iron and fold it over many times. This allowed the carbon to disperse throughout the sword, making a blade that was generally homogeneous. This folding ensured that any welding flaw did not go fully through the blade, thus helping to keep the blade from breaking under stress.
The Japanese also used several other techniques designed to produce a superior blade. They would enclose a high carbon center with a mild steel skin, allowing the edge to protrude. [Figure: Drawing of Japanese sword cross-section.] This kept a very sharp, hard edge, but with a soft back that could absorb shock. They also tried the reverse, with a soft core encased in high carbon steel. This served the same purpose. [Figure: Photo of one reproduction katana from the collection of Hank Reinhardt.]
The Europeans used a different technique. They would twist bars of high carbon steel with bars of low carbon, rough shape the sword, and then weld on a high carbon edge. The purpose was the same, to give a hard edge with a core that could take the shock of a blow and not break.
The two processes do not appear to have occurred at the same time. This method of manufacturing the katana is believed to have appeared about 1000 AD in Japan, and continues even today by some of the Living Treasures of Japan, those smiths who still forge superior swords. However, in Europe around 900 AD, smelting techniques had improved so that it was possible to get a cake of steel large enough to make a full steel sword. Not long after the debut of these swords, pattern welding as a method of making swords vanished, and all-steel swords began to appear.
There is an interesting historical novelty here. The first all-steel swords have a distinct shape. The blade is wider at the hilt, and tapers somewhat to the point. This puts the weight of the sword closer to the hand, and thus makes it quicker. Also, all of these early blades are marked with the name "ULFBEHRT" in nice large letters. Shortly thereafter copies marked "INGLERII" appear. [Figure: Photo of reproduction ULFBEHRT sword from the collection of Hank Reinhardt] We don't know anything concrete about the significance of these names.
It is rather hard for me to write without digressing. There are so many aspects that need to be brought out, and so many tales about swords, that it's really hard to stay one course. But here I go, back to making the sword.
After the sword was forged to shape it was filed, partially polished, and then hardened. This last was done by heating the sword to a bright red, and then immersing it in a tempering medium, in order of preference: water, brine, or oil, this last being more forgiving and easier on the steel. As soon as possible after the blade had been quench hardened, it was tempered.
The sword at the end of the hardening process was extremely hard and brittle, and most blades tended to warp under the stress. However, since the crystalline structure of the metal was still unsettled, there was a 15-minute window of opportunity when the smith could straighten the blade without breakint it. Then came the tempering.
The sword was then heated to the desired temperature, usually around 400 to 500 degrees, and kept at that temperature for an appropriate time, so that the temperature is consistent throughout the blade. It was cooled quickly in the medium of choice.
This produces a blade that is hard, yet also tough. By varying the amount of heat applied to the blade you can get varying degrees of hardness and flexibility. This frequently depended on how the sword was to be used as well as the length of the sword. A shorter weapon could be harder, as it would not be subjected to the same amount of torque as would a longer weapon. (Note that too much hardness could cause the edge to chip easily.) A longer weapon would have to have a greater degree of flexibility as simple leverage would add a great deal of force that would be applied to the blade in combat. The individual struck with a sword is highly unlikely to remain still, and his inconsiderate movements would place great stress on the blade.
One of the favorite themes in fiction is a rapier so superbly tempered that the blade can be bent so that the point touches the hilt, and when released, springs back to true. I have such a sword at home, that I picked up in Toledo, Spain. It is pretty, in a rather garish fashion, and is completely worthless as a weapon. I sharpened the blade, and could not penetrate a cardboard box! The blade flops all over the place, and you can't cut with it or thrust. But it is flexible!
Regardless of movies and fiction, the rapier was required to have a rather stiff blade. The rigidity was necessary, as it was a thrusting weapon, and had to at least penetrate a breastbone, and may have to deal with mail as well. As the rapier progressed and eventually changed into the small sword, its form changed to reflect the stresses it would be subject to. The blade was generally tempered to a strong spring. This allowed it to absorb the shock it would encounter, but still be rigid enough to penetrate. The stiffness was aided by cross sections. Many cross sections had a diamond shape, some with hollowed faces for less weight. One beautiful sword in my collection, which I came to own by way of Ewart Oakeshott, has a cross section that is literally a cross. Some cup hilts have blades that are thin rigid needles. The most effective small sword has a cross section that is triangular, with deeply hollowed faces. This is an extremely light and quick weapon. [Figure: Photo of reproduction of Oakeshott sword from the collection of Hank Reinhardt.]
But I digress. Let us return to the heat treating of the sword.
There is another form of tempering called "slack tempering." In this procedure the sword is heated up red hot, and then inserted into the cooling medium. It is kept there for a predetermined period, usually just a few minutes, and then withdrawn. This is done while the blade is very hot. The cooling medium has not sucked all the heat out of the blade. The residual heat then builds back up in the blade and then the sword is again quenched. This time it is left until cool, taken out and quickly straightened. This method is quick and requires less work, and was generally done on the cheaper swords. It does not give a good even temper, and results in a blade that has soft and hard spots.
Another form of heat treating was also used. This is called "case hardening." This was used a great deal in more primitive areas where the metal working skill did not approach that of Japan, Europe or the Near East.
The weapon was forged and pretty much completely polished. Then it was covered with some form of carbon-bearing substance, such as leather, charcoal or plant matter, generally placed in a sealed container and heated up to a red heat. It was then taken out, left to cool, and lightly polished. It was heated up one more time and quenched again. This operation left a thin skin of very hard steel, sometimes as hard as 64–65 on the Rockwell scale. The problem was that the surface hardening is only about 1/16 of an inch deep or less. The result was a very soft blade with a very hard skin. It was excellent for slicing, but rarely would it stand up to any real abuse. Javanese and Filipino knives and swords are generally made this way. Although they are highly regarded, and attributed with almost magical qualities in their areas, they really can't stand up to rigorous use.
The problems facing the early swordsmiths, regardless of their location, was how to get enough carbon into the iron. Remember, they didn't really know what the substance was. Early furnaces lacked the ability to reduce the iron ore to iron, and to heat it up long enough, and hot enough, for it to absorb carbon from the charcoal. Thus the manufacture of iron in sufficient quantity to make a sword was a long process. The iron had to be smelted and purified, the process repeated several times in order to get some small pieces of steel. But these small pieces of steel could be welded into a larger section, and lo and behold, a sword blade! And this brings us to pattern-welded swords, Damascus and Japanese sword blades.
As with many things, we do not know who first developed pattern welding. We do know that it was in use from at least the 2nd century AD, and continued up until about 900 AD. There are at least two Roman swords that we know were pattern welded after modern spectrographic analysis of the swords. These date from the 2nd century, and the workmanship on both is quite good, so the technique was around well before that. There are many swords dating from the 10th century that were pattern welded.
Pattern welding developed when it was found that if long thin bars of iron were placed in a container filled with charcoal and heated up red hot you got a steely iron. This is essentially case hardening. However, if you do this several times, then the iron bars became steel, with a good amount of carbon. The smith would take a few of these iron bars, wind them around each other and forge out a blade.* Then additional steel bars would be forge welded to the edges and the point. After being filed to final shape it would be hardened and tempered.
The forging would cause carbon migration from the steel bars to the iron bars, and if there was a sufficiency of carbon to start with, you ended up with a good, tough blade. But as you can easily surmise, a lot could go wrong. You might not have enough carbon to start with or, even if you do, it might leach out. This is where a very good smith was quite important, and why his reputation was his livelihood. A good smith did everything he could to assure that the swords he made were as good as he could make them. One thing he did was use the best ores he could get.
Iron ore comes in many forms. Bog iron was a very impure ore that contained all sorts of inclusions, such as phosphorus, arsenic and sulfur, that made it very difficult, if not impossible, to make a good sword. Other ores might contain manganese, which increased the toughness of the steel. Vanadium and titanium might also show up, and these also helped to make the sword tougher and stronger.
Pattern welding did not produce a magical sword, but if the smith was lucky, he could produce a good sword. Several of these swords have been tested, and the carbon content varied from .03 to as high as .06 per cent. Rarely was this evenly distributed throughout the sword, but there was enough to produce a tough, rather flexible blade.
DAMASCUS
The term "Damascus steel" is a very confusing one. It originally referred to swords that were purchased in Damascus, then it came to mean shotgun barrels that were forged together after being wrapped around a central core. Some also use the term to mean a type of steel produced in India that is now termed "wootz." In modern knife making it refers to taking bars of steel, forging them together and etching them to produce blades with patterns. And the term "Damascene" refers to gold work inlaid on the blade. For this book the term refers to Eastern swords, both where the blade is made of one type of steel, and one where the blade is forged with another steel to produce patterns.
The Indians developed a superior method of producing steel, and they did this quite early, approximately 200 BC. This seems shockingly early to most people, but Indian steel has long been regarded as the best. This was done by heating the iron ore in a crucible combined with various carboniferous items. As the iron began to absorb the carbon, the melting point lowered, and more carbon was picked up and dispersed throughout the iron. This produced a bloom of steel with a carbon content as much as three per cent.
This method of manufacture produced a bloom of steel that is called "watered steel" as the various minor impurities and crystalline structure of the steel gives a watermark effect. This could be heightened by various forging and even mechanical Damascus methods to produce swords of incredible beauty. Not only were they beautiful, they were excellent swords. This is the real source of the tales of Damascus swords that could cut through steel and do all sorts of wonderful things. European knights encountered these blades during the Crusades; much of the steel work was traded in and around Damascus, and there were even swordsmiths there. So the legend was born, but the actual source of the steel, and many of the swords, was India.
The Japanese did not have this method of turning the iron ore into steel. Although they used rather sophisticated methods of heating and purifying the ore, heating, reheating, beating the metal to remove impurities, and doing this with the usual Japanese thoroughness, the basic ore they started with was not quite as good as the Indian. But excellent techniques of manufacture, great care in the construction, and strict observance of ritual (which aided keeping to the precise time required for various operations) and the Japanese were able to produce truly excellent swords. Not the magic swords of movies, but truly fine weapons.
There is one incontrovertible fact about steel. The harder it is, the more likely it is to break, shatter, or chip. All of the efforts the swordmaker exerts are intended to minimize this. The Japanese wrapped soft steel around hard steel, and vice versa; differential tempering, with the edge left hard and the body soft, was also used. Oftimes the smith tried "packing" the edge (repeated hammering to make the edge denser and thus stronger). Most times the sword was tempered so that the whole blade had a tough spring—able to cut well and still be springy enough to absorb the shock of a blow. All of these things worked to a degree, but none of them produced the perfect sword. Since each weapon is made for a specific type of combat, each will have different requirements. There is simply no perfect sword.
Suggested further reading by the editors:
De la Bedoyere, Guy, The Finds of Roman Britain. B.T. Batsford, Ltd., London, 1989.
Grancsay, Stephen, V., Arms & Armor: Essays from The Metropolitan Museum of Art Bulletin 1920–1964, The Metropolitan Museum of Art, New York, 1986.
Spring, Christopher, African Arms and Armour.
*The bars would be forge welded into one piece before being forged into a blade.—Whit Williams