This Japanese ferrule adjustment tool (katsura) allows the metal ferrule of Japanese chisels to be uniformly adjusted before use. Compatible with various ferrule sizes, it facilitates the maintenance and precise adjustment of traditional chisels.

Manufactured by Ōuchi Chisel Manufacturing, this accessory is essential for users of Japanese chisels. It is recommended to adjust the ferrule gradually and to avoid using it on very thin models to prevent any risk of damage.