Sword Forging process

Swords are classic weapons of war. They have been used widely in the battlefield and have been put to use for different purposes such as thrusting, piercing, defending, and many other things. The swords have to be versatile and strong in order to meet the demands that could arise in the battlefield. The Japanese Katana is supposed to be a versatile sword that is a remarkable expression of the fine craftsmanship and the finesse of the Japanese Swordsmiths. They were indeed the masters of forging high-quality blades and the Quality depends on the steel, they use.

The steel Tamahagane is the name given to the steel used in the production of Samurai swords like the Katana. This special steel is smelted using a special process, which results in a substance called Kera. The kera is a mixture of various kinds of carbon steels.

Composition of Kera The steel with the lowest carbon content is known as the hocho-tetsu or the soft iron. This goes into the making of Shingane and it is considered the Core steel of the blade. The steels with a higher degree of carbon content called the Tamahaganeand the high carbon pigiron called the nabe-gane are used to forge the alternate layers of the blade using a very complex process. They are also used in the making of the hard steel that is used in the edge called hagane and Kawagane, the metal jacket which is springy in nature. Once the kera is separated it is subjected to folding.

Forging During the traditional sword-making process followed by the Japanese, They begin by folding the low-carbon iron several times in order to purify it. Now you get the soft metal that is used to make the core of the blade. The high- carbon steel and the high carbon pig iron are then forged to form alternating layers using the age-kitae process

Age-Kitae Process In this process, the cast iron is heated and then quenched in cold water. This is then broken into pieces and piled upand the whole thing is forge- welded, to form a single block. This block would be elongated, then cut and then folded and forge welded again. The folding could be done longitudinally or transversely. In either case, the process is repeated for about 8-16 times to get steel with homogenous carbon content to produce fine quality Katana as the Quality Depends on steel that goes into the manufacturing of the blade. When the steel is folded as many times, it yields a pure surface that facilitates the forge-welding process.