Atoplee 100mm Diamond Concave Polishing Grinding Cutting Disc Cut Off Wheel for Angle Grinder [15mm] Material: carbon steel, Coating: Titanium, 100% brand new and high quality. Wheel Diameter: 100mm,Hole diameter: 15mm,Weight: about 61g,Shape:center sag Suitable for portable cutting machine, grinder. Applicable for cutting gem stones,metal,glass,ceramics,porcelain, tiles,carbide,rocks,etc. Plays the role of a tool of craft work, jewelry making or silver smithing.