This 10 pcs electric polishing kits are for DIY polished engraving, cutting, polishing (wood, metal, mold polishing purposes). These are high quality 3mm high speed steel milling cutter for electric grinding accessories. Features: Our electric polishing kits has high speed steel rotary burrs, grinding head and rotary burr cutting tool. Suitable for processing cast iron, cast steel, carbon steel, alloy steel, stainless steel, copper, aluminum and other metals, also marble, jade, bone, nonmetal, etc. Can be replaced with small grinding wheel,and no dust pollution. High working efficiency, perfect grinding effect and long using life. Basically replace with handle small grinding wheel, and no dust pollution. Convenient to grind, simple to use, safe and reliable. Specifications: Color: Silver Material: High Speed Steel 4241 Hardness: HRC 60 Type: Drill Woodworking Cutter Shank Diameter: 3mm / 0.24in Total Length: 40mm / 1.57in Item Weight: Approx. 27g / 0.97oz Package Size: Approx. 8 * 3 * 1.1cm / 3.15 * 1.18 * 0.43in Package Weight: Approx. 30g / 1.06oz NOTE: 1. When the HSS rotary tool works on the pneumatic or electric tool, the rotate speed is usually 6000-40000 rpm, so you must clamp tight tool. 2. The cutting direction is from right to left even move, not like grinding wheel used for reciprocating cutting; be careful not to overexert (pressure is generally less than 4 kg). Suitable Applications: Carving of metallic and non-metallic surfaces. Processing cast iron, cast steel, carbon steel, alloy steel, stainless steel, copper, aluminum and other metals; Milling marble, jade, bone and other non-metallic. Using an engraving machine or mini-drill various forms of cutting / engraving. Package List: 10 * High Speed Steel Rotary Burs