Japanese Metallurgy and Swords
Mining
Mining in Japan ended quite quickly as they had few resources, It is believed they used techniques similar to others during the early centuries.
Smelting
Japanese ‘Tamahagane’ is steel formed by smelting iron in a specialty clay kiln for three days with a constant source of iron, the process is rigorous and very small mistakes will cause the entire batch to be spoiled, resulting in a restart of the process. The process takes 10 short tons of iron and 12 short tons of charcoal. The result is 2 short tons of kera of which only one ton of Tamahagane can be produced.
Selection
A single kera can typically be worth hundreds of thousands of dollars, making it many times more expensive than modern steels.The swordsmith will carefully break the kera apart, and separate the various carbon steels. The lowest carbon steel is called hocho-tetsu, which is used for the shingane (translated as “core-steel”) of the blade. The high carbon tamahagane and higher carbon steel, called nabe-gane, will then be forged in alternating layers, using very intricate methods to form the kawagane (or, “skin steel”).One of the most important processes is folding, where the metals are forge welded, folded, and welded again, as many as 16 times. The folding removes impurities and helps even out the carbon content, while the alternating layers combine hardness with ductility to greatly enhance the toughness. Currently, tamahagane is only made three or four times a year by Nittoho and Hitachi Metals during winter in a wood building and is only sold to the master swordsmith to use once it is made.
Sword Structures
There are many different types of sword structures. The best is still a matter of debate; the Soshu-Kitae is the only one able to achieve five body rank. This will be explained later. (see thumbnail picture)
Rough Forging
A folding process is used to blend the metals together (note that the hard and soft steels are not blended together this is purely to remove impurities, haha I made a pun).Then steel is then positioned correctly and fused together threw hammering and other traditional Japanese swordsmith methods.
Precise Forging and Touch-up
Next the sword is tempered, sharpened, engraved, and a custom hilt and guard are made. (No two swords will ever be similar let alone the same.)The sword is then tested for sharpness; traditionally they would lay five prisoners on top of each other flat and slash down the middle to see how many it could cut through cleanly and easily.Only about three blades were ever able to achieve five bodies; they were all made by Masumune and were Soshu-Kitae.Now blades are tested on Tatami mats; which are they same density and size as a human torso with a Bamboo stalk as a spine.
Famous Swords
Honjo Masamune
The Honjo Masamune represented the Shogunate during most of the Edo period and had been passed down from one Shogun to another. It is one of the best known of the swords created by Masamune and is believed to be one of the finest Japanese swords ever made. It was made a Japanese national treasure in 1939. The name Honjo possibly came about due to this sword's connection to the general Honjo "Echizen no kami" Shigenaga who gained the sword in battle.Honjo Shigenaga, general of Uesugi Kenshin in the 16th century, was attacked by Umanosuke who already possessed a number of trophy heads. Shigenaga was attacked with the Honjo Masamune which split his helmet, but he survived and took the sword as a prize. The blade had a number of chips from the great battle but was still usable. It was kept by Shigenaga until he was sent to Fushimi Castle,Bunroku around 1592–1595. Shigenaga ran out of funds and was forced to sell the sword to Toyotomi Hidetsugu, Toyotomi Hideyoshi's nephew and retainer. It was bought for 13 Mai, 13 ōban, which was 13 large gold coins. The blade was later valued in the Kyoho Meibutsu Cho at 1,000 Mai.It then went to Toyotomi Hideyoshi, Shimazu Hyogo Yoshihiro, again to Hideyoshi, Tokugawa Ieyasu, Tokugawa Yorinobu, and finally Tokugawa Ietsuna. It remained in the Kii branch of the Tokugawa family, the last known owner being Tokugawa Iemasa at the end of World War II.Apparently Tokugawa Iemasa gave the Honjo Masamune and 14 other swords to a police station at Mejiro in December 1945. Shortly thereafter in January 1946, the Mejiro police gave these swords to a man who identified himself as "Sgt. Coldy Bimore" (possibly a garbled phonetic spelling of the man's name) serving with the U.S. 7th Cavalry. The Honjo Masamune is without a doubt the most important of the missing Nihonto and its current location remains unknown.
Fudo Masamune
This is one of the few blades signed by Masamune that is not in question. It was bought by Toyotomi Hidetsugu in 1601 for 500 Kan and was passed to Shogun Ieyasu and from him to Maeda Toshiie. Maeda Toshitsune presented it again to the Shogun, possibly on his retirement. Later, the sword was handed down among the Owari Tokugawa. This blade is a tantō approximately 25 cm (8 sun 6.5 bun) with a carving of roots on the Omote (Front, outer edge) side. It also has chopstick like grooves (Gomabashi) on the back and a Dragon at the ura part of blade (Kurikara). The blade features an engraving of Fudo Myo-o, the Buddhist deity which gives this blade its name.
Hōchō Masamune
The "Hōchō" Masamune refers to any one of three particular and unusual tantō attributed to Masamune. These tantō have a wide body, unlike his normal slim and elegant work, making them appear quite similar to a Japanese cooking knife. One of the three blades has a Gomabashi in cutout (Sukashi). It was restored around 1919 and sold for approximately 10 Hiki; this was worth roughly 14¢ US at the time, rendering the price remarkably low. It is presently on display in the Tokugawa Art Museum.
Kotegiri Masamune
Kotegiri means "Kote cutter". In this case Kote is contracted word of Yugote, items of samurai that is equipped with his finger for using a bow. This name comes from an episode that Asakura Ujikage cut an opposing samurai's yugote in the battle of Toji in Kyôto. Oda Nobunaga gained possession of this sword and had it shortened to its present length. In 1615 it eventually passed down to the Maeda clan who in 1882 presented it as a gift to Emperor Meiji, a known sword collector.
Masamune in Harry S. Truman Library
A Masamune was given to President Harry S. Truman shortly after World War II. It is currently housed in the Harry S. Truman Presidential Library and Museum.
Today
There are less than ten practicing swordsmiths today with a handful of apprentices among them, it is a dying art that a small group of men are trying to keep alive, but with a rigorous smelting process and a tedious forging system; the swords end up costing quite a lot, $300-$10,000 with some collectors swords breaking the $100,000 mark, the remaining Masamune swords are beyond priceless. The price turns many buyers away, they want a $50 mall sword not a several hundred dollar collector’s item; this is what may ultimately kill the tradition of making these beautiful and highly lethal swords.
