Bosch 3 Piece HSS-AlTiN Step Drill Bit Set

The Bosch 3 Piece HSS-AlTiN Step Drill Bit Set is a professional-grade drilling solution that allows tradespeople to drill multiple hole diameters using a single bit, eliminating the need to swap between tools mid-task.

Each bit features a split-point tip for a clean, self-starting entry into material without pre-punching, and a CNC ground spiral flute that optimises chip removal whilst reducing vibration during operation. Axial and radial relief grinding ensure the highest levels of cutting smoothness and consistency across each step.

The bits are manufactured from HSS (high-speed steel) and coated with AlTiN (Aluminium Titanium Nitride), which extends working life significantly, particularly when used with coolant. Laser-marked diameter figures in both spiral flutes remain clearly visible throughout the life of the bit, making it easy to identify the correct step at a glance.

This set is suited to working with thin materials including sheet steel, stainless steel, non-ferrous metals, sheet plastic, and plastic. The 3-flat shank design prevents rotation in the chuck, ensuring secure high-torque transmission in both rotary drills and drivers. The set covers step diameter ranges of 4–12 mm, 4–20 mm, and 6–30 mm, making it a versatile option for electrical, fabrication, and general contracting work.

Features and Benefits:
• HSS-AlTiN coating extends bit life and performs well when used with coolant
• Split-point tip enables a clean, self-starting entry without pre-punching
• CNC ground spiral flute reduces vibration and improves chip evacuation
• Axial and radial relief grinding delivers consistent cutting smoothness across each step
• 3-flat shank prevents slipping in the chuck for reliable high-torque transmission
• Laser-marked diameter figures in both flutes remain legible throughout the bit's working life
• Three-bit set covers 4–12 mm, 4–20 mm, and 6–30 mm step diameter ranges

Specifications:
Version: HSS-AlTiN
Total length: 66.5 mm | 70.5 mm | 93.5 mm
Shank diameter: 6 mm | 8 mm | 10 mm
Step height: 4 mm (all bits)
Step diameter range: 4–12 mm | 4–20 mm | 6–30 mm
Net weight: 0.386 kg

Contents:
HSS-AlTiN step drill bit: 4–12 mm step diameter, 6 mm shank diameter
HSS-AlTiN step drill bit: 4–20 mm step diameter, 8 mm shank diameter
HSS-AlTiN step drill bit: 6–30 mm step diameter, 10 mm shank diameter