WoodOwl 09719 Tri-Cut 1-1/2-Inch by 7-1/2-Inch Ultra Smooth Auger Bit Patented Tri-Cut triple edge spurred design for fast, smooth cutting without resistance. Ultra smooth cutting for perfectly finished holes with "blowout". Lighter weight carbon steel construction than standard augers for safety and reduced fatigue without sacrificing strength. Burr-free lead screw for easy starts and pull-through without material build-up. Perfectly concentric for even and easy cutting of accurate diameter holes.