Yoroidōshi

The yoroidōshi (鎧通し) "armor piercer" or "mail piercer" were one of the traditionally made Japanese swords (nihontō) that were worn by the samurai class as a weapon in feudal Japan.

Description
The yoroidōshi is an extra thick tantō (Japanese dagger-like sword) which appeared in the Sengoku period (late Muromachi). The yoroidōshi was made for piercing armour and for stabbing while grappling in close quarters. The weapon ranged in size from 20 cm to 22 cm, but some examples could be under 15 cm, with a "tapering mihaba, iori-mune, thick kasane at the bottom, and thin kasane at the top and occasionally moroha-zukuri construction". The motogasane (blade thickness) at the hamachi (the notch at the beginning of the cutting edge) can be up to a half-inch thick, which is characteristic of the yoroidōshi style of tantō. The extra thickness at the spine of the blade distinguishes the yoroidōshi from a standard tantō blade.

Yoroidōshi were worn inside the belt on the back or on the right side with the hilt toward the front and the edge upward. Due to being worn on the right, the blade would have been drawn using the left hand, giving rise to the alternate name of metezashi (馬手差), or "horse-hand (i.e. rein-hand, i.e. left-hand) blade".

Gallery
 Image:Yoroi doshi tanto 1.JPG|Antique Japanese yoroidōshi tantō, showing the extra thick "motogasane" (sword thickness at hamachi) which is a characteristic of the yoroidōshi style of tantō. Image:Yoroi doshi blade thickness.JPG|Antique Japanese yoroidōshi style tantō showing the extra thick blade. Image:Yoroi doshi blade.JPG|Antique Japanese yoroidōshi style tantō blade. File:Yoroi doshi tanto 11.jpg|Yoroidōshi tantō. 