焼きの谷 (Yaki no Tani)
What is Yaki no Tani in Japanese Katana terminology?
Yaki no Tani refers to the lowest point of the blade pattern (Hamon) on a Japanese sword, located towards the edge (Ha). It is used to describe the low points of the tempering in irregular blade pattern (Hamon)s with variations, such as ""互の目乱刃"" (Gunome Midare), ""丁子乱刃"" (Chouji Midare), and ""湾れ刃"" (Notare).
The term ""Yaki no Tani"" is used to describe the shallow parts of the tempered blade that resemble a series of valleys when viewed as a whole. The term ""足が入る"" (Ashi ga Hairu) is used to describe the state where the Nie (tiny crystals) or Nioi (larger particles) at the bottom of these valleys extend thinly towards the cutting edge.
These descriptions are used to convey the intricate details and variations in the tempering patterns of Japanese swords, which are considered one of the key aspects in evaluating the craftsmanship and aesthetic value of the sword.