Made of extremely hard alloy steel, with high strength and hardness, durable, rust-proof, and anti-corrosion; it can stay with you for a long time Size: Fits 1/8 in. (3 mm) to 1 in. (25 mm); operates with full lubrication and below 400 RPM EASY TO USE: This deburring exterior chamfering tool makes it easy to chip away at the outer edges of flat bolts. Simply attach it to the drill and lightly press on the bolt head; easily and quickly secures the nut to be tightened Safe and efficient: The high-strength, high-hardness deburring drill bit can easily cut off the outer edges of bolts, pipes, and rods and remove burrs; quickly repair bolts and tighten the nuts in place without hurting your hands, producing sparks, or getting burned. ; Simplify the maintenance process Wide range of applications - External chamfering tools effectively machine stainless steel, hardened steel, mild steel, copper, brass, aluminum, fiberglass, wood, plastic, with or without threads Colour:black+blue Material:high speed steel Package Contents: 4 x Chamfer Tool