The japanese katana sword is the signature weapon of the samurai class. This sword evolved during the Muromachi period to replace the older tachi sword. The katana is carried with the blade pointed up, which allows it to be drawn and cut in a single motion.
The smiths who create katana sword use only the highest quality iron ore known as tamahagane. Smelters shovel the iron sand and charcoal into a rectangular clay furnace called a tatara, which heats to temperatures up to 2,500 degrees Fahrenheit. This process takes over three days and nights to yield the tamahagane that will be used to make the sword.
After the smith removes the tamahagane from the furnace, he or she heats it again to soften and strengthen it by heating and cooling it repeatedly, a process known as yaki-ire. This is done in order to create a transition between the hard, high carbon steel that forms the blade’s deadly sharp edge and the tougher, softer steel that makes up the body of the blade. The result of this differential heat treatment is a distinctive pattern or hamon that is visible on the surface of the blade. The hamon reveals the sword’s history, and demonstrates the skill of its smiths.
Once the smith has forged the blade, it is fitted with a handle or tsuka and a scabbard or saya. The hilt of the sword is often adorned with decorations or kozuchi that are symbolic of deities, animals and other things associated with Japanese culture. Visit site