棟焼 (Muneyaki)

What is Muneyaki in Japanese Katana terminology?

Muneyaki refers to a type of blade pattern (Hamon) in Japanese swords. It is a term used to describe the tempering pattern that extends from the edge of the blade (Habuchi) to the ridge (Mune) of the sword. This can occur when the scattered tempering (Tobiyaki) in the ground of the blade extends to the ridge, or when the tempering return (Kaeri) of the tip (Boshi) is long and intermittently extends downward.

In particular, it refers to the tempered blade where tempering is applied to the ridge independently. It is believed that this was done intentionally to enhance the aesthetic appeal by adding variation to the tempered blade, and at the same time, to increase the strength of the sword body, especially the ridge.