Master Mechanic, 6" Bi-Metal Hole Saw, 4-1/8" Arbor, 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, Can Be Used With 3/8" Bi-Metal Saw Mandrel, Bulk.