1mm diamond-coated grinding bit, ball shape grinder head, high strength, and good coaxiality.Made of carbon steel and the diamond coated grinding head, higher wear resistance, and durable use.This grinding drill bit is suitable for quickly cutting, sharpening, deburring, grinding, rust polishing, carving, and repairing.Good grinding tool for the rough grinding surface of materials such as jade, ceramic, glass, wood, marble, and precious stone.The 1/8 Inch (3mm) shank bit fits most electronic grinders, engraving machines, hanging mills, etc.Note - Please be careful of flying chips during use!.