Sword Forms — Understanding Blade Construction Types

Japanese blades have different cross-section forms depending on purpose and era.

Shinogi-zukuri: The most common form with a ridgeline called shinogi. Most katana and tachi use this construction.

Hira-zukuri: Flat construction without a shinogi ridge. Common in tanto and wakizashi.

Kiriba-zukuri: A variation with the shinogi closer to the edge. Found in older tachi.

Katakiriba-zukuri: One side flat, the other kiriba. A specialized form seen in Kagemitsu's tanto.