The bosch 3 piece hss step drill bit set is a versatile collection of stepped drill bits designed for smooth, burr-free drilling across multiple diameters without needing to change bits. Each bit in the set features a split-point tip that allows for an easy, accurate start without pre-punching, making them particularly well-suited for work on thin materials including sheet steel, stainless steel, non-ferrous metals, and sheet plastic. The cnc ground spiral flute design optimises chip removal and reduces vibration, contributing to consistently clean, round holes. Axial and radial relief grinding delivers high cutting performance and exceptional smoothness throughout the drilling process. The 3-flat shank prevents slipping in the chuck, while laser-marked diameter figures in both spiral flutes provide clear, durable readings during use. Each bit is manufactured from hss high-speed steel , offering extended service life when used with coolant. The set covers a broad range of diameters from 4mm through to 30mm across the three bits making it a practical choice for electricians, fabricators, and contractors who regularly drill or enlarge holes in sheet materials. Features and benefits: three hss step drill bits covering step diameter ranges of 4 12mm, 4 20mm, and 6 30mm split-point tip for easy starting without pre-punching cnc ground spiral flute for optimised chip removal and reduced vibration axial and radial relief grinding for high cutting performance and smooth results 3...