toolant Four Spiral Flute Cobalt Step Drill Bit(Pro Max), 4-22mm Impact Ready Four Spiral Flutes Unibit Step Bit, 1/4" Hex Shank Unibit for Metal, Stainless Steel, Aluminum, Wood, PlasticM35 COBALT HSS STEP DRILL Prefect for Stainless Steel Metal Sheet Wood Plastic Aluminum Sheet Copper and other metal sheets. ALUMINUM TITANIUM NITRIDE COATING With 35 Gigapascal(GPa) Nano Hardness harder materials can be cut and higher cutting speeds can be achieved. FOUR SPIRAL FLUTE Four cutting blades design guarantees a faster and smoother cutting. Feels like a hot knife through butter! 1 4" HEX SHANK QUICK CHANGE Quick release slot to eliminate