Metabo® Depressed Center Wheel, Type 27 Aggressive Cool Cutting, series: Plus Grinding, 7 in dia, 1/4 in Thickness, 5/8-11, A36M Grit, Medium Grade, Aluminum Oxide Abrasive, 8500 RPM Maximum, Resin/Resinoid Bond, Applicable Materials: Aluminum, Bronze, Copper and Brass. The 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. Metabo® 655760000 Plus Grinding Type 27 Aggressive Cool Cutting Depressed Center Wheel with Hub, 7 in dia x 1/4 in Thick, A36M Grit