How Is a Katana Made?

This page shares the main stages in the making of a katana. All Tetsuren swords are hand-forged.

1. Forging

The katana is forged following Japanese tradition. There are many techniques, depending on the type of forging: maru, kobuse, honsanmai...

Each technique uses different steels and an assembly of several layers, together with folding, in order to obtain a blade of the best possible quality.

Generally a soft steel is combined at the centre with a hard steel on the outside: shingane steel on the inside (low carbon content) and kawagane steel on the outside (high carbon content).

In this way the katana is both sharp and resilient.

2. Quenching

The blade, at about 800 °C, is plunged into water.

On contact with the water, the cutting edge of the katana cools very quickly and becomes extremely hard.

The rest of the blade is protected by a layer of refractory clay mixed with charcoal powder and other ingredients. This lets it cool more slowly and so keep greater flexibility. It is this stage that creates the line known as the 'hamon'.

3. Polishing

This stage brings out the grain of the steel as well as the hamon line. There are in fact several polishing methods, such as the 'kesho' method or the 'sashikomi' method.

The sword is polished with specially chosen stones, to give the blade its distinctive finish.

The most technical part is polishing the kissaki (the tip of the blade), which takes an enormous amount of time and brings out the boshi.