The Kyotoyama HSS #600 is a Japanese sharpening stone specifically designed for high-performance steels such as HSS (High Speed Steel) and Aogami Super. Its #600 grit effectively restores a dull edge and prepares the blade before the finishing stages.

Valued for its fast and consistent cutting action, it is suitable for knives as well as Japanese planes, chisels, and other precision tools. For optimal performance, it is recommended to soak it in water for 5 to 10 minutes before use.