覆輪 Fukurin / Covering Ring
What is Fukurin in Japanese Katana terminology?
This refers to the soft metal applied to the ear part, which is the outer periphery of the guard (Tsuba). For the purpose of enhancing aesthetics, the edge was covered with thin plates of gold, silver, copper, etc. In addition to enhancing aesthetics, it also served to prevent the guard from shining and wearing out due to friction with clothing, and to prevent clothing from being rubbed off. Therefore, gold was often used as the material.
In addition, it is also used for decoration and reinforcement of fittings, armor, saddles, etc.