Long ago, a master swordsmith and his most senior student met near a small stream.
Each of them brought one of their finest blades.
To show his teacher the quality of his craft, the student stuck his blade into the stream.
As leaves floated past, they were neatly cut in two, he held his blade up, smiling, proud of his work.
The master then stuck his blade into the stream.
As the apprentice watched, the leaves that floated past avoided the masters blade altogether.
He then understood and was ashamed of his amateur skills.
– unknown
There are three sacred treasures of Japan. And one of those is a sword. Considering the history of Japan it’s no wonder why the sword is so central to the culture. There are museums dedicated to swords. Volumes of print dedicated to the subject. Whole academic and professional careers based around swords. In true PGH fashion, this article, of course, is going to be woefully brief and very cursory in depth.
To me there is something about the imagery of the Japanese sword that is very hard to convey in words. Even the cheap replicas that adorn your neighbourhood sushi establishment carry a certain aura about them. But holding the real deal is something at an altogether different and visceral level. Feeling the heft of an actual katana in your hands is something that is pretty amazing, more so if you understand even a bit about how to wield one and the devastating effectiveness of it.
A real hand forged sword is both a weapon and piece of art beyond measure, where form and function are intricately blended together.
It all starts with steel. Of course steel is not just steel. Steel is a mixture of iron, and carbon, with varying percentages of each, and also of other elements that provide a wide range of characteristics and properties. It’s all chemistry at this point. Once you start melting it you move into metallurgy. But the first time you bang on that glowing ingot with a hammer you move from science and technology into the realms of art, philosophy, and mysticism.
The Japanese have been smithing swords for a very long time, so there has been a lot of that technology, art, and philosophy built up upon over the years. Roughly swords land in the following eras:
• Jōkotō – the earliest swords, built until around 900 A.D.
• Kotō – old swords from around 900–1596
• Shintō – new swords from 1596–1780
• Shinshintō – new new swords from 1781–1876
• Gendaitō – modern swords 1876–1945
• Shinsakutō – newly made swords from 1953–present
Over these years when swords were made there have been a wide variety of sword sizes and styles. In this article I will be referring to what is called a Katana Shinken. This is a more or less general term for the traditional Samurai sword with a curved ‘live’ blade. Typically between 60cm and 80cm in length. Although traditionally the unit of length measure for a Japanese sword is the Shaku. I will leave it at that without conversion into centimeters because there are both modern and historical Shaku which are different.
Almost all Katana Shinken style swords are of ‘composite’ construction. By that I mean (in simple terms) that there is usually an inner core of mild steel surrounded by covering of hardened steel. The reason should be obvious. A functional battle ready blade needs multiple characteristics. Two of the most critical are resilience and sharpness. And it’s always a trade-off between the two. The tougher and more resilient a blade becomes, the less sharp you can get it. The harder it is, the easier it is to sharpen, but conversely it becomes more brittle. That’s just how steel works. There are several ways one can achieve this composite structure that I will cover that a bit later.
Traditional steel used in Japanese swords is called Tamahagane. The iron required is found in iron sand and then processed into steel with the addition of burning charcoal in a time consuming and laborious process. The carbon content of the final product will vary depending on the tastes of the individual smith, but 0.7 percent would be considered somewhat typical, although it could be as high as 1.5 percent. There is only a small amount of steel currently produced in this fashion. As you might imagine, it’s expensive, and only sold to master swordsmiths. Those smiths not using Tamahagane, will use anything from commercial bar stock, to railroad steel, fish hooks and rusty bed springs and anything in between.
Regardless of the source, once the steel is in the smith’s hands he can begin the forging process. At this point the smith can also adjust the carbon content of the steel if required. There are a number of different techniques that a smith can employ. Swords can be one piece with, the carbon content carefully manipulated between the centre of the blade and the edge, or they can be constructed of multiple layers forged together. In this latter case the process begins with a core of mild steel being shaped and formed. This core is called the Shingane. The process involves repeated heating and hammering of the ingot in the smiths forge. While this can be all done by hand, and is done so by the master smiths, some sword makers today also incorporate a power hammer for at least part of the process. Once this billet is ready, the smith will turn his attention to the actual blade. The outer covering is called the Hadagane and is not laminated as is mistakenly thought by some people, but repeatedly folded over onto itself, producing instead thousands upon thousands of crystalline layers. This will eventually be formed into a ‘U’ shape into which the Shingane is inserted, and the two pieces are then forged welded together. It should be noted that there are other methods that use three or even up to seven different pieces of steel to build up the blade.
The smiths next task is to draw the metal out into roughly its final dimensions and shape. Again, this is either done by hand hammer, a power hammer, or by a combination of the two. Next up is quenching. This is where the final hardness of the blade is determined. Steel is quenched by heating it to a suitable temperature and then relatively rapidly cooling it. Steel can be quenched in air, oil, or water. Traditional Japanese methods employ water. Typically using water is the fastest way, and will result in the hardest, most sharpenable material, although it can impart unwanted brittleness.
In olden times the guarding of the secrets of the craft was very serious business. As an old tale (likely apocryphal) goes: a smith visiting a great master once dared to test the temperature of the masters quenching water. He stood aside the trough and slyly dipped his hand into the water, but he was not sly enough, as the master witnessed this act. Assuming nefarious intent, he had no choice and quickly drew his sword and sliced the visitors hand off at the wrist. Perhaps the punishment came too reflexively though, as the master considered the visitor, bleeding and writhing in pain before him. His hand had indeed felt the water temperature, but his brain remembered it. So his head was the next to go.
This potential for brittleness is solved by using what is known as differential quenching. In the traditional method this is accomplished by coating the blade with clay prior to heating. The clay is painted onto the blade in varying thickness which cause different thermal properties in different areas. A thick coating on the sides and the spine of the blade will ensure slower cooling and increased toughness. A thin coating, or maybe even none at all, on the edge will allow for rapid cooling and thus a hard easily sharpened surface. This differential cooling also causes the blade to warp and give it its final curve. As you might imagine this is very difficult to control, and can take years to master. Even the best smiths can and do lose blades during the quenching process. There is an additional side benefit to the clay coating, and that is the creation of the Hamon. This is a very distinctive and unique pattern that forms on the steel because of variations in the clay coating thickness, and is basically the demarcation between areas of differing hardness. Some smiths are so adroit at the application of the clay, that the Hamon, becomes their signature.
The last step in the blades geometry is usually forming the bevel on the cutting edge. Traditionally this would be done using a draw knife. Additionally at this time grooves called Bo can be cut into the sides of the blade, along with any decoration, and the smith’s actual signature is usually carved into the tang. Some sword makers will give their blades a rough polish and sharpening, before passing them along to craftsmen who specialize in sharpening and polishing. Other sword makers will complete the blades fully themselves. Sharpening and polishing is an art unto itself and those processes can take just as long as the forging of the blade itself. As such I will not cover those topics at this time.
Likewise, there are several other components that I won’t discuss in detail now, that go into a completed sword. The Habaki, Tsuba, Tsuka, Saya, and various other small bits and pieces and cordage are involved. Some of these items are works of art in their own right, and are also often made by separate artisans.
There have been many famous and legendary swordsmiths throughout history some of the more notable ones are:
Gorō Nyūdō Masamune 五郎入道正宗 (1264–1343)
Nagasone Kotetsu 長曾禰 虎徹 (1597 – 1678)
Sengo Muramasa 千子村正 (16th century)
In the current era, Yoshihara Yoshindo is considered one of the best swordsmiths alive. If you wish a sword from this master, you are expected to visit his forge in person before he will consider making a blade for you, and prices start at around $60,000.00, and only go up from there… Be prepared for a wait of 3 months or longer as well.
Not that it’s going to be for sale anytime soon, but there is always this…
