Self-feed Wood Bits, 18 in Hex Key Extension

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 in. hex quick change impact shank that fits 1/2" or larger electric drills or 7/16 in. hex impact wrench drills. Precision milled shank eliminates runout and wobble. Forged in one piece from high carbon steel for maximum strength under tough drilling conditions.