The 11th subject of our new series on craftsmanship is about traditional Japanese sword-making. Swords are weapons that have captured the imagination of millions, and are synonymous with nobility and skill. And of these weapons, Japanese katanas are celebrated for their quality and cutting edge. The process for making these famed weapons is laborious and highly ritualized, but no less effective for it. As such, traditional Japanese sword-making techniques are treasured, and the old masters revered as legends. And none are more legendary than Masamune.
This is my third article on Japanese craftsmen. I wrote about Ken Okuyama, last month. You may be wondering why a logo design company like ours has articles on Japanese Sword Making on it’s blog. Like I mentioned in the past, I love craftsmanship and consider that we are LDW are true craftsmen and have a great passion of creating designs of the highest quality. I like to compare what we do with the skill and passion and tradition that goes into making a Japanese sword.
A Legendary History
Goro Nyudo Masamune lived some time in the 13th century. No known dates for his life and death exist, and there are relatively few accounts of his life as a person. Masamune is known primarily through his work, which contributed to his status as a legendary historical figure.
Historians suspect that Masamune worked in the Sagami province of Japan. He is believed to have been trained by swordsmiths from the Bizen and Yamashiro provinces, and trained many other swordsmen in turn—fifteen are known, and ten of them are legends in their own right, named the Juttetsu, or the “10 Great Disciples of Masamune”. However, few of those ten are actually likely to have actually studied under Masamune.
Crafting a Japanese Blade
Japanese blades are constructed using a very complex and time-consuming process involving the smelting and application of several different types of steel.
Instead of using blocks of iron ore, Japanese smiths get their metal from iron sand, which is placed into a clay pot in alternating layers of sand and coal. It can take as much as a week to complete this process, which results in a steel bloom known as kera. This kera is composed of multiple types of carbon steel, each with different carbon levels, which are essential to forging the actual sword.
In order to make the actual blade, carbon steel is heated, hammered, and folded multiple times. This folding distributes the carbon more evenly within the material and removes impurities—this last bit is essential, because Japanese iron was notoriously low in quality, and every effort had to be made to purify it. The steel is folded so much that it can create up to 65,000 layers when finished.
When the iron is assembled before forging, soft steel makes up the blades core, which is surrounded and wrapped by the harder layers. This gives the blade the best of both qualities—the flexibility to withstand heavy use, combined with hardness and ability to retain a cutting edge. In addition to this assembly process, the forged blade is heat treated using a process called differential quenching. Differential quenching involves painting different areas of the blade with varying amounts of clay. Thusly prepared, some parts of the blade cool faster than others, enhancing desirable qualities of hardness and flexibility in the appropriate sections.
The Masamune Touch
While modern Japanese blades are assembled using two to three layers of steel, ancient blades use four to five. Masamune’s blades, however, used as many as seven. This put him far above most of his contemporaries, and required extraordinary skill and patience to pull off successfully.
Masamune’s works are also characterized by their chikei, or leading edges, with undulating lines that served as evidence of the quenching process. Many Japanese swordsmiths—Masamune among them—applied clay in different ways to form unique patterns and designs.
Blades created by Masamune bear two names: Masamune’s, and the name of the sword itself. The most famous Masamune blade is the Honjo Masamune, which saw use in World War II but is currently unaccounted for. Other blades are highly prized by collectors, with some serving as key museum pieces.