How does a tachi differ from a katana in construction?
Updated Mar 2026
While both are single-edged Japanese swords with curved blades, the tachi and katana differ in several meaningful ways. The tachi typically has a longer blade - often exceeding 70 cm - and a more pronounced curvature (sori), measured from a different reference point than on a katana. The tachi was traditionally worn edge-down suspended from the belt by the sageo, which is why sageo attachments and saya hardware on tachi mountings are configured differently than on katana. Katana, worn edge-up thrust through the obi, emerged later historically as the dominant samurai sidearm. For collectors, these differences are visible in blade geometry, the placement of the mei (signature) on the tang, and the overall balance point of the finished piece.