What makes a full-tang katana different from a rat-tail tang?
Updated Feb 2026
The tang, or nakago, is the portion of the blade steel that extends into the handle. A full-tang katana features a tang that runs the entire length of the tsuka, maintaining a width and thickness consistent with the blade's overall geometry. This construction distributes stress evenly across the handle during any movement or handling, making the sword structurally sound as a single integrated piece. A rat-tail tang, by contrast, narrows dramatically into a thin rod welded or threaded into the pommel, concentrating stress at the transition point. For collectors, full-tang construction is a key indicator of quality craftsmanship because it reflects traditional Japanese swordsmithing methods where the nakago is forged as one continuous piece with the blade, then fitted with a wooden tsuka, wrapped in samegawa, and secured with mekugi pins through drilled holes in the tang.