The katana is the Japanese sword that combines both art and function. It is up there with chainsaws and spiked baseball bats on the list of “weapons I would take into a zombie apocalypse that aren’t guns.” Its distinctive curve allows it to perform both slashing and thrusting moves, making it the weapon of choice for mounted combat and foot warriors alike.
It is made of a special steel known as Tamahagane, produced from iron sand and charcoal in a clay tatara furnace. This process creates a unique steel that has varying levels of carbon, creating a hard, brittle edge and soft, resilient body. The curved katana design also allows the back of the blade (Mune) to be thicker and stronger, while the sharp, piercing point (Hamon) is thin and flexible.
When the sword is complete, it undergoes a crucial heat treatment known as Yaki-ire. A clay slurry is applied to the blade, with a thicker layer on the body and spine of the blade, and a thinner one along the edge. This causes the edges to cool quickly, hardening them, while the body side is cooled slower, softening it. This creates the distinctive curve of the katana, and gives it the ability to bend without breaking.
Once the katana is tempered, it is finished with a ray skin layer wrapped over an outer cotton cloth called Ito. Modern ito may be leather, cotton, or rayon, and features modern ornaments that give the sword identity and character. Ito helps prevent the tsuka from slipping in the hand, and protects it from moisture that could cause rust. buy the katana here