5 Pack, 4-1/2″ x 1/4″ x 7/8″, Heavy Duty Metal, Grinding Wheel, Takes Care Of The Toughest Grinding Jobs With Its High Performance Aluminum Oxide Grain & 3 Sheet Fiberglass Construction, Aggressive Grain Concentration Allows For These Grinding Wheels To Handle Heavy Duty Grinding Of Ferrous Metals Steel, Iron Welds, Edges, Weld Blends, Stainless Steel & Hard Alloys.