Z24R - Saitech Pipeline. Tough zirconium grain. High performance cutting for the toughest applications. Ferrous metals (steel, cast iron, etc.). Stainless steel, high tensile alloys. Specifications: Max RPM - 8500, 5/8-11 Super-Lock hub. Tech Info: Only wheel designed for both cutting and light grinding, eliminating the need for 2 separate wheels. General pupose formulation provides optimum performance over a wide range of applications. All sizes reinforced with the highest quality fiberglass for maximum safety and performance. Super-Lock Hub on all 5/8-11 threaded wheels is the safest, vibration-free design.