Industrial HSS Step Drill Bit Kit

This 3-piece step drill bit kit uses HSS4241 high-speed steel as its base material, treated with a cobalt coating to enhance resistance to wear and thermal softening. Each bit incorporates a straight-slot shank, a 118° split point tip and a grooved two-flute structure to support efficient material removal and stable drilling behaviour. Dimensions and tolerances follow standard UK workshop expectations for interchangeability and chuck compatibility. The included bits cover overlapping but purpose-built ranges: Bit #1 (4–12mm, 5 steps) focuses on fine adjustment tasks; Bit #2 (4–32mm, 15 steps) supports full-spectrum sheet metal work; Bit #3 (4–20mm, 9 steps) serves general-purpose applications requiring moderate reach and clarity of step identification. All bits are suitable for use with battery-powered drills typical in UK homes and small businesses. Validated for drilling into common British building and fitting materials — including powder-coated steel, marine-grade aluminium, ABS plastic enclosures and softwood carcasses — with performance feedback gathered from real installation scenarios rather than lab-only testing.