For drilling large diameter holes in wood for pipe, conduit and other applications * Replaceable coarse screw point drills quickly in dry, wet and gummy wood * All bits have a 7/16-Inch hex quick change impact shank that fits 1/2-Inch or larger electric drills or 7/16-Inch hex impact wrench drills * Precision milled shank eliminates run out and wobble * Forged in one piece from high carbon steel for Maximum strength under tough drilling conditions