Wood Owl 03719 1-1/2" Diameter x 7 1/2" Long Nail Chipper Tri Cut Auger Boring Bit PTEE Coated 1 1/2 diameter x 7 /12 long Patented Tri-Cut design with three precision ground cutting edges and three flutes engineered to optimize performance Cuts extremely smooth holes with minimal blowout on exit hole 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