Saitech Ultimate Performance - Stainless Steel. Combines fast cutting with extremely long life for tough cutting applications. Ideal for foundry applications (gates, risers). Stainless steel, high tensile alloys. Ferrous metals (iron, steel, welds, etc.). Specifications: Max RPM -6600, 5/8-11 Super-Lock hub. Tech Info: Manufactured with patented 3M Cubitron grain to outlast standard aluminum oxide wheels. Unique bonding system lets you make faster burr-free cuts. Designed to provide very long life for fewer wheel changes and less downtime. All sizes externally 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.