Zantetsuken (斬鉄剣?) is Japanese for "iron-cutting/slashing iron sword". It normally refers to a blade formed out of exotic materials rumored to be able to cut through steel and/or iron. The term was often associated with blades created by the feudal swordsmith known as Kobayashi Yasuhiro.
Usage
See Special:Whatlinkshere/Etymology:Zantetsuken for a list of articles using this term.
This is an etymology page: a page detailing the origins of terminology used in the series in regards to real world culture and history.