Katana

Japanese for sword. Can also refer to a specific long sword used by the Japanese Samurai, sometimes accompanied by a shorter sword or wakisashi. The Katana is slightly curved and has a sharp edge in only one side. It is primarily used for slashing, and can be wielded one or two handed (the second being the most common mode). The art of drawing the katana is called iaido?, and other sports related to the katana are kendo, aikido and kenjutsu?.

Production methods

Japanese swords and other edged weapons were manufactured by an elaborate method of repeatedly heating, folding and hammering the metal. This practice was originated from use of highly impure metals, stemming from the low temperature yielded in the smelting at that time and place. In order to counter this, and to homogenize the carbon content of the blades, the folding was developed (for comparison see pattern welding), and found to be quite effective, though labour intensive.

The distinctive curvature of the katana comes from the differential [heat treating]? it is subjected to. Unlike swords produced in many other locations, Japanese smiths did not harden the entire blade, but only the cutting edge. The hardening process will make the edge part of the blade contract less than the untreated steel when cooling down, forcing the blade to curve. The combination of hard edge and soft back of a katana and other Japanese blades is what cause them to be resilient and yet retain a good cutting edge.

Myths

Many myths surround Japanese swords, the most frequent being that the blades are folded an immense number of times, gaining magical properties in the meantime. Note that the number of layers in a sword blade is the number of folds to the power of two. When speaking of folds, the layers and actual foldings are often confused. As for magical properties, see above.