Master Mechanic, 1 Piece 278 BiMetal Hole Saw, M3 High Speed Steel Cut Edge, 178 Depth Of Cut, 46 Variable Tooth Pattern Provides Less Vibration, Delivering Faster, Smoother Cuts Then Conventional Hole Saws, Features Built In 38 Mandrel Which May Be Used With 38 Or Larger Drill, Recommended For Cutting Soft Or Hard Wood, Nail Embedded Wood, Stainless Steel, Pipe, Rubber Conduit, Pilot Drill Included, Clamshell Package