Wood Owl 03707 5/8" Diameter x 7-1/2" Long Nail Chipper Tri Cut Auger Boring Bit PTEE Coated 5/8 diameter x 7 1/2 long Patented Tri-Cut design with three precision ground cutting edges and three flutes engineered to optimize performance Unique Tri-Cut head balances the bit as it cuts and minimizes kick-back as nails are reduced to chips PTFE Teflon  coated to minimize friction and allow quick and easy chip ejection in the sticky woods Can be resharpened