WoodOwl 02808 11/16-Inch by 18-Inch Spur Auger Precision grinding and heat-treat processes enable the end user to cut nails and other materials encountered in the work without damage to the cutting edge. Safer than other single-spur auger bits because the consistent hardening and concentricity along the length of the bit keeps it in line without forcing the user to compensate for "walk". 7/16" shank with the quick-change power groove makes for easy bit changeover. Perfectly concentric design, which is guaranteed through the tightly-controled heat-treat and hardening processes, means that the hole cut will be exactly true to the diameter of the bit.