The PTI 3pc HSS Step Drill Set with 1/4" Hex Shank is ideal for cutting holes in a variety of materials, including steel, brass, wood, and plastic. This versatile set includes three step drills, each designed for precision and efficiency. Sizes Include : 4 - 12mm 6 - 20mm 6 - 30mm Shank Type : 1/4" Hex Material : High-speed steel (HSS) Applications : Suitable for use on steel, brass, wood, plastic, and more Packaging : Supplied in a sturdy box with Eurohook and barcode Brand : PTI