What is Hamon(刃文)?
- Hamon is the outline of the hardened area of the blade.
- The 2 types of crystal particles form the outline pattern, the rough and large type is called NIE(沸) and the very small particle, like fog or mist, is called NIOI(匂).
- The outline pattern results from YAKIIRE(焼き入れ), the hardening process, where a swordsmith insulates a blade with the cray to harden the edge. The amount and pattern of the clay create the appearance.
- Hamon has nothing to do with the sharpness but the durability of the sword because the secret of Japanese sword durability is the ratio of hardened and unhardened areas. In other words, a sword with wide or scattered pattern tends to break easily, while a sword with calm pattern absorbs shock more.