[Size] - Shank Diameter: 1/4", Head Diameter: 22mm / 0.87 inch, Total Length: 48mm / 1.89 inch..[Details] - Grinding Bit Material: White Corundum, Shape: Ball, Mesh: 80 Grit, Recommended Speed: 25-40m/s. The ball shape is suitable for surface and edge grinding..[Material] - White corundum has a higher hardness than brown corundum. The particle size is easily broken, the edges and corners are sharp, good self-sharpening, strong grinding force, high efficiency, and high-temperature resistance..[Applications] - Suitable for grinding of hardened steel, high carbon steel, general high-speed steel, alloy steel, etc. cutting tools and workpieces, precision grinding of measuring tools and instrument parts, and also suitable for form grinding..[Notice] - The new corundum grinding bit should be tried at a low speed before use. If there is a jumping problem, do not continue to use it. Flying chips may be generated during use. Please use jigs, non-slip finger stall, and wear protective glasses when using this corundum grinding bit.