HELLER TOOLS 312264 HSS-Co Stepstar 19-osainen metalliporanteräsarja DIN 338

For metalworkers and maintenance technicians who need a full range of precise holes in alloyed steel, stainless steel, cast iron, and non-ferrous metals, the HELLER TOOLS Stepstar set delivers 19 cobalt-alloyed twist drill bits in a robust metal case. Each bit is fully ground to DIN 338 with a 135° split point for self-centering and reduced walking.

Key specifications

• Drill bit type: Twist drill bit
• Material: HSS-Co (cobalt alloyed high speed steel)
• Number of pieces: 19
• Standard: DIN 338
• Point angle: 135°
• Point type: Split point (self-centering)
• Shank type: Cylindrical
• Manufacturing process: Fully ground
• Tolerance: h8
• Surface finish: Bright / Bronze
• Drill bit diameters: 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 mm
• Suitable materials: Alloyed and unalloyed steel, stainless steel, cast iron, non-ferrous metals
• Packaging: Robust metal case

Why choose it

The cobalt alloying improves heat resistance and hardness, allowing higher drilling speeds and longer tool life compared to standard HSS. The split point geometry reduces thrust and improves accuracy, especially on curved or uneven surfaces.

Ideal use cases

• Drilling precise holes in steel plates, stainless steel sheets, and cast iron components
• Maintenance and repair work in workshops, factories, and on-site service
• Use with corded drills, cordless drills, and drill presses

Good to know

The set covers diameters from 1.0 to 10.0 mm in 0.5 mm increments, providing a versatile range for common metalworking tasks. The metal case keeps the bits organized and protected.