Bosch HSS-AlTiN Step Drill Bit – 666442

The Bosch HSS-AlTiN Step Drill Bit in the 4mm–12mm range is the compact, versatile choice for precision work on thinner materials, ideal for smaller-diameter holes and deburring tasks in sheet steel, sheet plastic, non-ferrous metals, and stainless steel. Its stepped design means a single bit covers every size within the range, saving time and reducing tool changes. The split-point tip allows an easy start without pre-punching, while the CNC ground spiral flute ensures optimised chip removal and minimal vibration for consistent, even drilling. Axial and radial relief grinding delivers the highest cutting smoothness throughout. Built from HSS and coated with AlTiN, the bit offers maximum longevity and requires no coolant. Laser-marked figures on both spiral flutes make diameter identification quick and reliable, and the 3-flat shank locks securely in the chuck for powerful, slip-free torque transmission. Features and Benefits: • 4mm–12mm stepped range — one bit covers multiple diameters • Split-point tip for clean starts without pre-punching • CNC ground spiral flute for optimised chip removal and reduced vibration • Axial and radial relief grinding for maximum cutting smoothness • HSS construction with AlTiN coating — no coolant required • Laser-marked diameter figures for clear, durable identification • 3-flat shank for secure, high-torque chuck transmission Specifications: Diameter Range: 4mm–12mm