Dewalt, D180064, Hole Saws, Bi-Metal, Drilling Accessories, 4 Inch, Bi-Metal 4" Bi-Metal Hole Saw The Dewalt 4" Bi-Metal Hole Saw Is An Extremely Durable And Useful Attachment. Use This To Increase Your Cutting Efficiency And Decrease Your Work Time. Superior Build Quality Means You Will Use Less Blades On Your Jobs. A Must Have For Any Professional Or Do-It-Yourselfer. Features: Double Tooth Design Strengthens Each Tooth For Longer Life And Improved Durability - Sharper Tooth Geometry Cuts Material Faster For Faster Drilling - Thick, Hardened Backing Plates Prevent Thread Stripping - Deep Cut Style Holes Saws Will Cut 2X Material In 1 Pass - Increased High Speed Steel Height (Highest In The Industry) Improves Hole Saw Durability - Specifications: Hole Saw Size: 4" - Max Speed: 85 Rpm - Dewalt Is Firmly Committed To Being The Best In The Business, And This Commitment To Being Number One Extends To Everything They Do, From Product Design And Engineering To Manufacturing And Service.