Making a samurai sword
Tamahagane roughly translates to ?¢‚Ç¨Àújewel steel?¢‚Ç¨‚Ñ¢ and it is mainly used in the creation of Samurai swords like the katana and also some tools. This steel is created from black sand. The smelting process for this material is different from that of most modern mass production steel. A clay vessel about four feet tall, twelve feet long, and four feet wide is constructed. This vessel is known as a tatara. After the clay tub has set, it is then fired until it is dry. A charcoal fire is started from soft pine charcoal. The smelter will then wait for the fire to attain the correct temperature. Once the correct temperature is attained, he will direct the addition of iron sand called satetsu. This sand will be layered in with more charcoal and more iron sand over a seventy two hour period. There are constantly four or five people involved in this process. It takes approximately a week to create the tatara and finish the iron conversion into the steel.
The finished product
When the process is complete, the clay tub will be broken and the steel bloom known as kera will be removed. By the end of the process, the tatara will have consumed approximately ten short tons of satetsu and twelve short tons of charcoal, leaving approximately 2.5 short tons of kera. From this material, less than a ton of tamahagane will be produced. The swordsmiths will very carefully break the kera apart and separate the various carbon steels. The lowest carbon steel is known as hocho-tetsu and this is used as the core steel of the blade. The high carbon tamahagane and the higher carbon nabe-gane will then be forged in layers. Very intricate methods will be used in order to form the kawagane, also known as skin steel. Tamahagane is only made three or four times a year and it is only sold to the master swordsmiths once it is created.