Greenlee 66PT-1/2 Nail Eater II Wood Boring Bit, 1/2" x 18" Made of high quality carbon alloy steel that cuts through nails and provides up to 3 times longer life Unique patented design cutting angle provides smoother starts and reduced cutting loads Self-feeding screw point draws bit through wood even after multiple sharpening Patenteddesign for improved cutting and cleaner holes and cutting edge is hardened through for longer life