Lately I read a couple of good books on the histroy & making of the Japanese Sword and tought it would be a good idea to shear that with our readers so I decided to write a few posts about it. If you found something incorrect or you like to add something, don’t hesitate to leave a comment !
The technology that led to the development of the Japanese sword originated in China and was brought to Japan in the 4e-5e century A.D. At that time these swords were known as chokuto and did have a straight blade. There are scholars that do believe that a lot of these swords were made in China. By the Heian period (794-1185), the Japanese smiths made great process in improving their forging techniques and the straight swords changed to curved blades.
The main reason for this (changing from straight to curved) was the fact that the warriors that fought from horseback were in need of a ‘slashing’, and not a ‘trusting’ sword. The sword also had to be slightly longer and light enough in order to use it with one hand. So the Tachi was born. A nicely curved blade (with more sori than the katana we all know now) tapered strongly from the base of the blade to a very small point. These swords are also worn with the edge down, where the katana are worn with the edge up.
The hamonline that was developed during this period was more broad and Ashi started to appear. Ashi are almost invisible stripes of soft steel in the area of the hamon (hardened adge) that help limit the extend of damage should the blade begin to chip.
During the Kamakura period (1185-1333), when Japan was under the rule of a warrior class, smiths learned to insert a soft core of low carbon steel (more flexible) into the blade. This process is know as lamination and had several different techniques were the kobuse lamination is the most popular.
In the Nanbokucho period (1333-1392), many swordmaking methods were practiced throughout Japan and could be divided into 5 main schools :
1. Soshu – located at Kamakura , known for itame hada and midareba hamon in nie deki.
2. Bizen – located at Okayama, known for mokume hada and midareba hamon in nioi deki
3. Yamashiro – located at Kyoto , known for mokume hada and suguha hamon in nei deki
4. Yamato – located near Nara, known for masame hada and suguha hamon in nie deki
5. Mino – Located at Gifu, known for hard mokume hada and midareba mixed with togari-ba
These schools are called the Gokaden or the five traditions. Bizen was the most active and most popular school during these times.
The Connoisseur’s Book of Japanese Swords
The craft of the Japanese Sword