BlueSpot Metal Grinding Discs are specially designed to provide highly efficient grinding. Ideal for use with normal steels, alloy steels and non-ferrous metals. High quality grinding disc with high resistance to breakage and long-lasting durability. Suitable for all makes of angle grinders. Specially designed to provide highly efficient grinding. Ideal for use with normal steels, alloy steels and non-ferrous metals. High quality grinding disc with high resistance to breakage and long lasting durability. Diameter: 115mm (4 1/2"). Bore: 22.23mm. Thickness: 6mm. Maximum safe speed: 13300 RPM (80m/s).