5Pcs 1/4 Inch Double Cut Tungsten Carbide Rotary Burr Die Grinder Shank Bit Set The 5pcs carbide burr bits are double-cut head, for electric or pneumatic tool drive (can also be used in machine tool). Features: For 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, suitable for deburring and polishing cast iron, cutting, engraving carving, cast steel, carbon steel, alloy steel, stainless steel and other materials. Machining hardness reach HRC70, for the most work, rotary burr set it can replace Petiole small wheel. And their working life is 10 times longer than normal HSS Burr, 200 times longer than Petiole small wheel. Double-cut style has rows of cutting teeth cut in two intersecting directions for quick material removal and a rougher finish. carbide is approximately twice as stiff as steel, with a Young's modulus of approximately 530–700 GPa (77,000 to 102,000 ksi), and is double the density of steel—nearly midway between that of lead and gold. It is comparable with corundum (α-Al2O3) in hardness. They all feature toughened and hardened steel shanks that provide strength. This stops bending and reduces vibrations for an improved tool life.  Specifications: Material: Carbide Color: Silver Groove: Double Cut Solid Cutting Margin Diameter: 6/8/10/12/14mm Shank Diameter: 6mm / 0.24in Total Length: 60-65mm / 2.36-2.56in Package Weight: 190g / 6.7ounces Package Size: 100 * 72 * 19mm / 3.94 * 2.83 * 0.75in Packing List: 5 * Burr Bits