The Spyder Stinger Mach-Blue armor plated high speed steel (HSS) step bits are high performance metal drilling bits that provide exceptional drill bit quality and durability, drilling performance, and value. The Mach-Blue Armor Plating combined with the advanced M-series alloy tool steel construction and proprietary heat treatment make these bits truly revolutionary - they retain sharper cutting edges for longer, have reduced heat build-up and cutting friction, and increased durability, rigidity, and breakage resistance. These incredibly durable bits are the pro's choice for precision drilling, extended bit life, and value. Ideal for electrical work and other applications in sheet metals, including enlarging existing holes. Up to 50x more holes and 2x faster than titanium or black oxide coated step drill bits Super-hard Mach-Blue™ Armor Plating retains sharper cutting edges, and reduces heat build-up and cutting friction Durable drill bit for long drill life, precision holes, and increased speed and productivity in tough to drill applications Impact rated 1/4-in speed hex won’t slip in conventional 3-jaw chucks and is ideal for use in quick change impacting power tools Optimized 135-degree self-centering split point cutting geometry won’t walk or wander – even on pre-hardened or curved surfaces Advanced M-Series alloy tool steel construction and proprietary heat treatment increase drill bit durability, rigidity and breakage resistance Ideal for drilling stainless steel, mild steel, aluminum, stacked materials and other difficult to drill alloys Made in the USA 16-Step bit, 3/16 - 1-1/8-in Sub-Brand: Mach-Blue Diameters of Holes Drilled: 3/16-in to 1-1/8-in Number of Hole Sizes: 16 Shank Size: 1/4-in Step Size: 1/16-in Material: High-speed steel Package Quantity: 1 Set/Individual: Individual Shank Type: Hex Warranty: None Brand/Model Compatibility: Universal CA Residents: Prop 65 Warning(s): Yes UNSPSC: 20121600