Before revision: San Mai , in the context of metal blade construction/metalwork, refers to a knife, blade or sword that has the hard steel hagane forming the blade's edge, and the iron/stainless forming a jacket on both sides.
After revision: , in the context of metal blade construction/metalwork, refers to a knife, blade or sword that has the hard steel hagane forming the blade's edge, and the iron/stainless forming a jacket on both sides.