The katana is perhaps one of the most iconic swords in Japanese culture. It has graced the pages of countless Japanese novels and was the sword of choice for Samurai in feudal Japan. With its curved blade, long handle designed to accommodate two hands, and hilt that locks into the obi (sash) of the wearer, the katana is an icon that has risen to mythical heights in pop culture. From Beatrix Kiddo slaughtering the Crazy 88 in Kill Bill to Samurai Shinzaemon turning a village full of invaders into shish kebab in 13 Assassins, the katana is a staple in action and martial arts films.
To make a katana, the swordsmith starts with high-quality steel called tamahagane. Iron sand and charcoal are heated in a clay furnace to create crude steel, then hammered, folded, welded, and heated again for multiple iterations to give the steel its layered structure. The smith then cuts and grinds the tamahagane to the proper length and shape, removing the black taint from the metal as it is shaped.
Once the smith is satisfied with the shape of his katana, he heats it to critical temperatures to harden it. He places the softer, weaker, and thicker portion of the tamahagane on the spine of the sword while the harder, stronger edge is forged at the cutting surface. The hamon, or differential line, created by this process is what makes the katana so durable and able to cut through bone with ease. buy the katana here