Auger Wood Drill Bits. The Auger Drill Bit is made for drilling into most woods. For drill bit diameters 1/4"- 5/16", these bits have a 1/4" shank. For drill bit diameters 3/8"- 1", these bits have a 3/8" shank. The 17" long Auger Dill Bits have a 7/16" shank. These longer drill bits are designed for heavy duty construction applications.