Katana were the sword of choice for samurai, or military nobility in feudal Japan from the Heian period (794 to 1185 AD) through the early Edo period (1603-1868). The katana’s graceful curves and sharp edge were well suited to both the slashing moves of mounted combat and the thrusting motions of close-combat. Its gentle curves also facilitated the quick draw necessary to defeat an enemy or execute a mercy killing, a ritual Japanese suicide known as seppuku. The katana’s form and function were crafted together to create a perfect whole.
The katana is made from tamahagane, a traditional steel that is forged by heating it in a clay tatara furnace to a high temperature. The hard outer layer, called kawagane, is wrapped around a softer, more ductile core, or shingane. This process produces a blade with a high strength to weight ratio. It also helps to reduce brittleness. The blade is then quenched in water, rather than oil, to achieve a higher degree of tempering and a finer Hamon (blade pattern).
Once the blade is forged, it’s sent for polishing by a sword craftsman known as a togi-shi. This step is essential because even a single mistake could render the blade useless, so it takes years to learn the craft. A polished katana is as beautiful as it is functional, with its delicate lines and intricate patterns that reveal the layers of folded steel. Other specialized craftsmen then produce the hilt, hand guard, and scabbard for the sword. The keywords I will use are