Features: These burrs are made of tungsten carbide aluminum for high hardness, high abrasion resistance. There are total 6 pieces burrs in various shapes that you can use for many purposes. 6mm round shank would fit many electric powered or pneumatic powered tools. Could cut cast iron, cast steel, carbon steel, alloy steel, stainless steel, copper, aluminum, marble, jade, bone, etc. Widely used for carving, shaping and for the removal of sharp edges or corners, burrs and excess material. Specifications: Material: Tungsten carbide aluminum Shank Diameter: 6mm Cutting Diameter: 10mm Head Shape: A/D/E/C/L/F Speed: 6000RPM~40000RPM Processing Hardness: 85HRA Note: 1, Rotary file in pneumatic or electric tools, the speed is generally 6000-40000RPM, must clamp the tool firmly. 2, Cutting direction should be from right to left uniform movement, not like the use of grinding wheel as reciprocating cutting; be careful not to force too much (the pressure is generally not more than 4 kgf). Package Includes: 6 x Rotary Burrs