Drill bit set AWTools AW STEP TWIST M2-TiAlN 4–39 mm, step twist design, HSS with TiAlN coating

AWTools AW STEP TWIST M2-TiAlN 4–39 mm is a drill bit set made from M2 high-speed steel with a TiAlN (titanium aluminum nitride) coating and a step-twist geometry that produces progressive cutting diameters in a single tool. The set covers hole sizes from 4 mm up to 39 mm and is intended for drilling, enlarging and deburring holes in metals and softer materials. The design is compatible with standard hand drills and drill presses, offering a combined approach to staged hole sizing without the need to change bits frequently.

Advantages

The M2 HSS substrate provides wear resistance and toughness appropriate for a range of workshop applications, while the TiAlN coating increases surface hardness and improves heat resistance for extended tool life under elevated cutting temperatures. Step twist geometry enables successive diameter increments along the flute, allowing drilling and reaming-like enlargement in a single pass and reducing setup time. The set’s diameter range from 4 to 39 mm covers many common hole-sizing tasks, and the bits are suitable for use in both portable drills and stationary drill presses.

Suitable for

• Drilling and enlarging holes in steel and non-ferrous metals
• Creating stepped holes and countersinking in a single operation
• Deburring or chamfering hole edges after drilling
• Workshop and maintenance tasks requiring staged hole sizing

Key specifications

• Material: M2 high-speed steel (HSS)
• Coating: TiAlN (titanium aluminum nitride)
• Geometry: step twist (progressive cutting diameters along the flute)
• Diameter range: 4 mm to 39 mm
• Intended use: drilling, hole enlargement, deburring in metals and softer materials
• Compatibility: usable with standard hand drills and drill presses

How to use

Mount the selected step-twist bit in the drill chuck and secure it firmly. Use appropriate clamp fixtures or a vice to secure the workpiece. Start drilling at low to moderate speeds suitable for the workpiece material and apply steady feed pressure; the TiAlN coating allows higher cutting temperatures but excessive speed can still reduce tool life. For larger diameter steps, consider backing out periodically to clear chips and prevent clogging. Use cutting fluid when working with ferrous materials to improve chip evacuation and reduce thermal loading.

Usage recommendations

For best results, select a rotational speed and feed rate matched to the workpiece material: lower speeds for hard steels, higher speeds for softer metals and non-ferrous alloys. Use light to moderate pecks when reaching larger step diameters to ease chip removal, and apply cutting fluid on ferrous materials. Inspect bits for wear and recoat or replace when cutting edges become rounded or performance declines.