The Klein 59009 High-Speed Steel Step-Drill Bit is a single flute cutter for a true round hole every time that works in most metals, plastic and wood. Other features include: Non-walking split point tip design. Permanent, easy-to-read laser-etched hole size. Tri-lobe shank for firm grip in drill chuck. Depth penetration for each step: 1/8-Inch. Electric drill size: 1/2-Inch and larger. Number of Hole Sizes per Bit: 10 in 1/8-Inch increments. Pilot hole required: No. Quick Reference Number: 9. Size Range (Hole Diameter): 1/4-Inch-1-3/8-Inch. Weight: 0.15-Pound.