- This set includes three hexagonal titanium-coated step drill bits for sheet metal work and body repair: 4-12 mm, 4-20 mm, and 4-32 mm. - Material and durability: bits are made from high speed steel with a titanium coating for added wear resistance and sharpness. - Size and length notes: the 4-12 mm bit length is approximately 6.7 cm (2.64 in); the 4-20 mm bit length is approximately 7.4 cm (2.91 in); the 4-32 mm bit length is not specified. - Key benefits: step drill design lets you drill and enlarge holes in one operation; hex shank provides a secure grip in the drill chuck; broad size range covers multiple hole sizes with a single set. - Compatibility: suitable for standard drills with hex shanks and for drilling metal, plastic, and thin materials commonly found in workshops. - Practical use scenarios: 1) Automotive body repair: create clean, step-like holes for wiring, rivets, or pass-throughs without multiple tools. 2) Metal fabrication: enlarge holes in aluminum or thin steel sheets with precision. 3) DIY projects: install electrical boxes or conduit fittings into metal panels with fewer tool changes. - Why this set: versatile hole-size coverage in one kit, durable construction, and a design that reduces tool changes while delivering reliable performance.