Lenox Speed Slot Hole Saw, 400 rpm Aluminum, 140 rpm Stainless Steel, 60 rpm Fiber Glass, 110 rpm Ceramic Tile, 50 rpm Iron Speed, 3-3/8 in Diameter, Carbide Cutting Edge, Applicable Materials: Abrasives, Cast Iron, Stainless Steel, Steel, Wood, Suitable for: Snap-Back 2L, 6L Arbor Models