Metabo Depressed Center Wheel, Type 27 General Purpose, Series Original Grinding, 412 in dia, 14 in Thickness, 78 in, C24N Grit, Coarse Grade, Silicon Carbide Abrasive, 13300 RPM Maximum, ResinResinoid Bond, Applicable Materials Concrete, Natural and Artificial Stone, Cast Iron, Ductile Iron, Masonry Materials, NonFerrous Metals, Brass and BronzeThe Quality of Cutting and Grinding Wheels Depends on Several Factors The Grain Size, Shape and Quality Determines How Aggressive a Wheel Is The Right Mix of Bonding Resins, Additives and Fiberglass Reinforcement Determines The Wheel Life Metabo Cutting and Grinding Wheels are Designed and Manufactured in Accordance With Our Most Stringent Specifications So That They, in Combination With Our Power Tools, Achieve The Best Performance and Productivity, Saving Time and Money