Fits size: 8-32 bolts (.164) up to 3/4-10 (.750) - (4mm -19mm).Material:High speed steel.made of CR12MOV steel, high strength and hardness.Simple operation, using the lowest speed on the drill bit, and then slightly applying pressure to remove the burr.Quickly repairs damaged bolts and tightens the nuts in place;simplifies the repair process, eliminates the need to replace expensive or hard-to-find hardware.Effective on Stainless Steel, Hardened Steel, Mild Steel, Copper, Brass, Aluminum, Fiberglass, Wood, Plastic, no matter it is with or without screw thread.Warm Note:This tool works by way of shearing metal layer by layer.Slow speed,along with no unnecessary cutting and the use of cutting oil or another lubricant will bring it long life.Color: silverProducts include: 1 x Hexagon Shank Deburring External Deburring Chamfer Tool1 x Triangular Shank Deburring External Deburring Chamfer ToolSize: 50*28 mm.