Bosch HSS-AlTiN Step Drill Bit – 666480

The Bosch HSS-AlTiN Step Drill Bit in the 6mm–39mm range is designed for professionals who regularly need to drill larger-diameter holes in thin materials, such as sheet steel, sheet plastic, non-ferrous metals, and stainless steel. Covering an extensive 6mm to 39mm spectrum, this single bit is particularly valuable for electrical enclosure work, HVAC installations, and general metalwork where a wide range of hole sizes is required. The split-point tip ensures a precise, burr-free start without pre-punching, even at larger diameters. CNC ground spiral flutes optimise chip removal and minimise vibration for smooth, controlled drilling throughout the entire range. Axial and radial relief grinding provides consistently high cutting performance at every step. The HSS construction and AlTiN coating maximise service life without requiring coolant, and laser-marked diameter figures on both flutes make it easy to identify the correct size on the fly. The 3-flat shank locks securely in the chuck for confident, high-torque transmission. Features and Benefits: • 6mm–39mm stepped range — covers a broad spread of larger diameters • Split-point tip for clean, accurate starts without pre-punching • CNC ground spiral flute for optimised chip removal and reduced vibration • Axial and radial relief grinding for consistent, high cutting smoothness • HSS construction with AlTiN coating — no coolant required • Laser-marked diameter figures on both flutes for fast, reliable identification • 3-flat shank for a secure grip and high-torque transmission Specifications: Diameter Range: 6mm–39mm