These mounted stones incorporate a unique Sol Gel ceramic abrasive (3M Cubitron grain). The Sol Gel abrasive, produced by Sol Gel processing, is both hard and tough. It provides exceptional durability and cut rates in grinding mild, high-carbon and stainless steel as well as many nonferrous alloys. Under normal use, their cut rate and wheel life are two to three times that of Red and Blue Mounted Stones. Particularly suited for precision grinding. Form and radius holding are greatly increased due to Sol Gel's durability. Light Blue Mounted Stones are extremely tough in all grades, chemically pure and of uniform quality. All are 120 grit. Can be dressed with our Tru-Stone #3801030.