Width of cut 1.8mm. Centre hole 3mm Designed to replace fragile stone discs. Fits Dremel and other hobby drills.Use to cut piano wire, perspex, all composites, woods, ceramics, stone and vacuumed formed mouldings etc. Running speed 5,000 - 20,000 RPM. Use at 10,000 RPM and slower for cutting perspex, plexiglass, lexan etc. Will not chip or crack material. Recommended by EAA workshops for cutting aircraft canopies.