1/4 to 1-3/8 Inch Step Drill Bit Straight Grooved Double Fluted, M2 High Speed Steel Drill bits for Hole Drilling in Stainless Steel, Copper, Aluminum, Wood, Plastic Exceptional Cutting Performance: Crafted from M2 high-speed steel, this step bit cuts cleaner and smoother. With 50% more tungsten and 150% more molybdenum than standard bits, it offers remarkable durability. Additionally, vacuum heat treatment and nitride surface hardening further enhance its performance. Continuous Operation: Our precisely polished steps and clear size markings allow you to see the target hole size during drilling without interruption. This feature saves you time and minimizes unnecessary hassle. Easier, Faster, and Cleaner: Thanks to high-precision CNC machining and years of optimized design, this bit delivers effortless, fast, and clean cuts, significantly outperforming average step bits on the market. Heavy-Duty Versatility: This bit is capable of drilling through stainless steel, hardened metal, mild steel, galvanized steel, aluminum, copper, plastic, wood, and other materials of similar or lower hardness. It can handle up to 12 gauge (2.7mm) thickness in stainless steel. Multiple Hole Sizes: No need for a full kit. This single step bit features five marked sizes, allowing you to drill five different hole dimensions, saving you the time and effort of changing bits. The marked sizes include: 7/8", 1-1/8", 1-7/32", 1-1/4", 1-3/8".