Hitachi 728259 1/2-inch x 18-inch Auger Drill Bit 1/2-inch by 18-inch auger drill bit with 3/8-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 1/2" x 18" Auger Bit 3/8" shank Precision design High speed steel Wood or Plastic