The Secret of Tamahagane — Understanding Japanese Sword Steel

Tamahagane is steel made from iron sand, exclusively for Japanese swords. It's produced once yearly by tatara smelting in Shimane Prefecture.

Over three days and nights, iron sand and charcoal are alternately fed into the furnace, producing a steel mass called 'kera.' The finest portions are selected as tamahagane.

Tamahagane's low impurity content makes it ideal for folding and forging. Its unique resilience, different from modern industrial steel, achieves the sword's ideal of 'neither breaking nor bending.'