Crafted from high-performance aluminum oxide grain for durability and optimal material removal, DeWALT Type 27 HP metal grinding wheels grind and shape a variety of metals and non-ferrous materials. High grain concentration for aggressive grinding action and smooth-running wheels.High-performance aluminum oxide grain for long life and high material removalHigh grain concentration for aggressive cutting action and smoother running wheelsProprietary material mix ensures durable long life wheelsThree full sheets of fiberglass for durability and safety