Made of Tungsten Carbide for high hardness, high abrasion resistance. The machining hardness can reach to HRC70. Cutting Edge Diameter: 8-10mm, Shank Diameter: 6mm(approx. 1/4 inch), overall Length: 150-160mm(approx. 6 inch) Generally use with handheld electric or pneumatic tool drive (can also be used in machine tool). The speed of the electric or pneumatic tools usually is 6000-50000 revolutions per minute. Double cut head rotating burrs, suitable for fine detail work on cast iron, cast steel, carbon steel, alloy steel, stainless steel, marble, jade, glass, wood and plaster. Widely used for metalwork, tool making, model engineering, wood carving, jewelry making, metal surface processing, welding, chamfering, casting, deburring, grinding, ect. Specification: color: as show Material: Tungsten steel solid carbide Cutting Head Type: Double Cut Shank Diameter: 6mm(approx. 1/4 Inch) Overall Length: 150-160mm(approx. 6.0-6.3 inch) Cutting Edge Diameter: Large F--10mm; Small F--8mm; C--8mm; D--8mm Package Included: 4 x Tungsten Carbide Rotary Burrs