3mm Diameter Sphere Point Diamond Coated Burrs Glass Drill Bit drill bits Fit most professional electric drills, best for replace nail drill bits. variety materials Can be used to various applications including carving, grinding and etching on a variety materials. Shank Diameter Shank Diameter: 3mm / 1/8"; Total Length: 45mm / 1.77" Material Material: diamond, metal; Head Diameter: 3mm / 0.11" Ball shape Ball shape, diamond coated head. Can be installed on electronic grinders, hanging grinders and hand drills Used for engraved Used for engraved, trimmed, precision ground and internally ground cemented carbide for jades, ceramics, glass, precious stones, alloys, woods Granularity Granularity: 150# Material Diamond,Metal Color Silver Head Type Ball Shank Diameter 3mm Head Diameter 3mm Grain Size 150 # Length 45mm Package Size 14.3 x 6 x 2cm/5.63 x 2.36 x 0.79"(L x W x H) Weight 106g