Hitachi 728256 5/16-inch x18-inch Auger Drill Bit 5/16-inch by 18-inch auger drill bit with 5/16-inch shank diameter Precision design creates less wobble in the drill and bit Self-feeding tip and wide throat leave cleaner holes Ideal for wood, plastic and metal Comes with a 30-day limited warranty 5/16" x18" Auger Bit 5/16" shank Precision design High speed steel Wood or Plastic