Firepower Ginding Wheel 3-Pack Aluminum Oxide 0.625-in 24-Grit Grinding WheelFull reinforced with resin bonded aluminum oxide to ensure safety at high speed and to increase bonding and impact strength Designed for use on air or electric powered right angle or vertical shaft grinders With hub, grade: A24R Max. RPM: 18,300 Features Sub Brand Ginding Wheel Series Name N A Application Grinding and cutting Material Aluminum oxide Type Type 27 Wheel Type Grinding wheel Grit 24 Diameter (Inches) 0. 625 Thickness (Inches) 0. 125 Arbor