Hachiwara

The 鉢割 (also kabuto wari or hachi wari), meaning `helmet breaker` or `skull breaker` was a type of knife-shaped weapon, resembling a jitte in many respects. This weapon was carried as a side-arm by the Samurai class of feudal Japan. ==Types== Hachiwara were usually around 350mm long, some larger versions are around 450mm long. There were t...
Found on http://en.wikipedia.org/wiki/Hachiwara

HACHIWARA

A short defensive rod called helmet breaker.
Found on http://www.samuraisword.com/glossary/index.htm
No exact match found