What is Yasurime in Japanese Katana terminology?

The term "Yasurime" (鑢目, やすりめ) refers to the patterns applied to the tang (Nakago) of a Japanese sword to prevent the blade from slipping out of the handle (Tsuka). In the era of ancient swords, the focus was on functionality, and it was common to finish the tang as it was after hammering it down. However, as time passed, the tang underwent changes. During the period of new swords, decorative Yasurime also appeared. Yasurime was applied not only to the flat surface but also to the ridge, blade direction, and end of the tang, and there were also designs with unique motifs, which attracted attention from a design perspective.

Types of Yasurime: