Lenox Speed Slot Hole Saw, 900 rpm Aluminum, 350 rpm Stainless Steel, 140 rpm Fiber Glass, 270 rpm Ceramic Tile, 110 rpm Iron Speed, 1-3/8 in Diameter, Carbide Cutting Edge, Applicable Materials: Abrasives, Cast Iron, Stainless Steel, Steel, Wood, Suitable for: Snap-Back 2L, 6L Arbor Models