Katana Sword

The samurai sword is very often called a katana sword or simply katana. The name katana usually refers to Japanese samurai sword that has somewhat standardized size and curvature as older predecessor of the katana sword featured longer blade length (usually length higher than 23.6 inches) and more curvature.

The samurai katana is known by its characteristic features such as a thin, single-edged and curved blade, long handle suitable for two hands and circular or square guard. The katana sword is famous for its sharpness and it has been historically associated with the Samurai warriors of feudal Japan.

The katana sword originated during the Muromachi period (1392-1573). The reason behind its origin was the need for the ability to quickly draw the sword and cut the enemy in single movement. To facilitate this, the katana was worn with the blade facing up. Previously the sword was worn with the blade facing down.

The length of the katana sword differed. At the end of the 14th century and the beginning of the 15th century the katana blade was between 27.6 and 28.7 inches. In the early 16th century the length of the katana blade was shorter and it was about 23.6 inches. At the end of 16th century the length of the blade want back to 28.7 inches.

Samurai warriors often were equipped with two swords. One was the katana sword and the other one was a wakizashi sword which was similar to katana but much shorter. Often they also had a similarly shaped dagger called tanto. When the katana sword is paired with the wakizashi, such setup is called a daisho.

The Japanese katana sword is made from special steel called tamahagne. The characteristic curved shape of the katana sword is obtained during quenching. Before the quenching the katana sword is straight. During quenching the edge of blade of the katana sword forms martensite which is a much tougher crystalline structure compared with the softer and thicker in the back of the blade. The Japanese swordmakers can achieve this by covering the back of the blade with paste made of clay mixed with ashes and rust. Only the edge of the blade is exposed and this results with the edge to become much harder. The root cause of the curvature achieved during quenching is the different in density of the steel in the back of the blade and in the edge of the blade. The iron carbide in the edge of the blade has lesser density compared with the steel in the back of the blade.