Master Mechanic, 7″ x 1/8″ Arbor, Metal Wheel, With 5/8″ Diamond Knockout, Constructed With 2 Pieces Of Extra Strength Fiberglass For Long Life, Premium Grain For Added Wheel Life & Speed Of Cut, High Quality Resin Bonds 100% Inspected Before Use For Product Consistency & Quality, Applications Include Cutting All Types Of Ferrous Metals, Steel, Rebar, Tubing, Studding & Decking, Max RPM Rating 8,700.