The katana is one of the most iconic Japanese swords. Its long, curved blade makes it ideal for both slashing moves in mounted warfare and thrusting attacks on foot. The design also enables the back of the blade (mune) to be thicker and more robust than the cutting edge (ha), making it an exceptionally strong weapon.
The smiths of the Muromachi period produced some of the most revered swords in history. During this time, the katana became increasingly curved to suit combat styles that emphasised the use of close-quarters hand-to-hand fighting. The blades were also made shorter, wider, and thicker, and the tang was strengthened to prevent breakage. These changes in design made the katana an excellent combination of strength, durability, and flexibility.
After the sword has been forged, it undergoes a crucial process called differential tempering. This involves applying a clay slurry to the body and spine, and spreading a mix of coal dust and ash on the blade’s cutting edge. The sword is then heated and quickly quenched in water, creating different zones of hardness within the steel.
The katana is now ready for its final stages of forming and polishing. The smith may use the kozuchi, which is an oblique hammer to form the ridge lines and a cross section of the body of the blade. After that, the smith grinds the sword using a rough plane. A mirror finish is then applied, and any blemishes or scratches are polished away. click on this page