Tsushima is natural stone with estimated grit approximately 5000 JIS

Gokumyo should be used with water as a lubricant

Premium series utilizes CBN grain made in the USA

All Venev diamonds use FEPA-F grit classification

cgsw resin bonded diamond for kme Micron Grit:40 Tsushima is natural stone withColumbia Gorge Stoneworks, Inc. operated by David Scott, the developer of Edge Pro Matrix diamonds, introduced a full line of resin bonded diamonds for knife sharpening. CGSW Resin Bonded Diamonds virtually don't wear with proper use and are easy to dress when needed. Since they don't break down themselves while sharpening the only mess is the water and swarf from your knife. CGSW Resin Bonded Diamonds is a premium level diamond series utilizing CNC