Master Mechanic, 6 piece, bi-metal hole saw set, m3 high speed steel cutting edge, 1-1/2" depth of cut provides easy cutting in the toughest applications, features 3/16" backing plate which eliminates need for separate drive plate on hole saws under 3" in diameter & prevents mandrel strip out, designed to cut hard & soft wood, nail embedded wood, stainless steel, pipe, rubber & conduit, carded. Hole saw sizes: 1 1/2", 1 1/4", 1 1/8", 1", & 7/8".