頭椎大刀 Kabutsuchi no Tachi / Head shape Long Sword

What is Kabutsuchi no Tachi in Japanese Katana terminology?

This is a decorated long sword (Tachi) made of iron or bronze with gold plating, produced in the late Kofun period. It is a straight sword with no curvature. The characteristic feature is that the head (Kashira) of the handle (Tsuka) is spherical like a clenched fist, a style unique to Japan. It is considered a ceremonial long sword.