Katana is a sword of samurai (Japanese feudal warriors) which was designed to be both deadly blade and elegant weapon in one package. It was the samurai’s most prized weapon for both its artistic value and its practicality, as well as its religious and spiritual significance as a sacred treasure, since the samurai were believed to live with their swords in a very close relationship.

The katana is the result of a centuries-old process that sought to balance three highly desirable qualities: not to break, not to bend and a razor sharp cutting edge. The forging technique known as the Tatara-buki method sought to achieve these goals by using a specialized type of steel, called tamahagane. This special steel was made by heating iron sand and charcoal in a clay tatara furnace. This smelting technique produced a raw steel with different carbon concentrations that a blacksmith would later hammer, fold and weld repeatedly to work out the impurities and create the layered structure that makes up a katana.

This blending of hard and soft steel is what gives the katana its strength and flexibility. A samurai swordsmith would use the harder steel to create the outer portion of the blade, while a softer, tougher metal was used to make the inner core of the blade. This process also created the wavy line on the blade called the Hamon, a visual indication of the sword’s special forging and differential heat treatment. Manga Katana collection