DEWALT high performance masonry cutting and grinding wheel have a silicon carbide grain for long wheel life in all masonry materials. They have a high grain concentration for aggressive grinding action and smoother running wheels. The proprietary wheel design ensures durable long life wheels and 3 full sheets of glass in every 1/4 In. wheel and 2 full sheets in every 1/8 In. wheel added durability and user safety. These wheels are ideal for grinding and cutting concrete, cast iron, ductile iron, and other masonry materials.