toolant Four Spiral Flute Cobalt Step Drill Bit(Pro Max), 4-32mm Impact Ready Four Spiral Flutes Unibit Step Bit, 1/4" Hex Shank Unibit for Metal, Stainless Steel, Aluminum, Wood, PlasticWARRANTY If you are not fully satisfied for any reason, please contact us for 100% refund or replacement. If the hex shank snap off, please contact us for replacement. FOUR SPIRAL FLUTE Four cutting blades design guarantees a faster and smoother cutting. Feels like a hot knife through butter! TiAlN COATING With 89HRC surface hardness, harder materials can be cut and higher cutting speeds can be achieved. M35 COBALT HSS STEP DRILL Prefect for Stainless