WeldTec, 9/16" x 17", Ship Auger, Made Stronger & Last Longer Because A Harder Cutting Edge Is Welded To The Base Material, 2X Nail Cutting Life Compared To Standard Irwin Ship Augers, Patent Pending Welded Cutting Edge, Wide Flutes, 7/16" Quick Change Impact Shank, Fully Forged Body On Bits 3/4" Diameter & Larger.