IVY Classic 09008 5-Hole Electrician's Step Drill Bit, 1/4-1-1/8-Inch, 1/Card M2 high-speed steel drills produce perfectly round, burr-free holes. Precision ground with a bright finish, Premium Swift Bore (Registered Trademark) For drilling metal, wood and plastic in up to 1/8-inch thick material. Sizes laser-etched on bit for easy hole size identification 3/8-inch Tri-lobe shank won't slip in the drill chuck and split point provides fast penetration and accurate starting center without punch Cone shape of the bit adds strength and prevents bit flexing while drilling 5 Hole Sizes: 1/4, 3/8, 1/2, 7/8, 1-1/8-inch, Max Material Thickness: 1/8-inch, Shank: 3/8-inch tri-lobe