Rotary File, Rotary Bit Set, port and polish kit cylinder head aluminum porting kit 6pcs Tungsten Carbide Aluminum Rotary Files Burr Set 6mm Shank 10mm Cutting Diameter with High. These burrs are made of tungsten carbide aluminum for high hardness, high abrasion. 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.