When it comes to drilling, the choice between solid carbide and high-speed steel (HSS) drills depends on your machine, material, volume, and budget. Both have a place in the workshop — this guide helps you pick the right one for your application.
The Core Difference
HSS (High-Speed Steel) drills are made from alloyed tool steel (typically M2 or M35 cobalt grades). They’re tough, resistant to shock and vibration, and can be resharpened multiple times. Solid carbide drills use a cemented tungsten carbide substrate — much harder and more wear-resistant than HSS, but also more brittle.
Speed and Feed
Carbide can run at 3–5× the cutting speed of HSS in the same material. On a CNC machine with rigid toolholding, this translates directly to higher productivity. On a manual drill press or older machine with spindle runout, carbide’s brittleness becomes a liability and HSS is the safer choice.
Material Suitability
| Material | HSS | Carbide | Recommended |
|---|---|---|---|
| Mild steel | ✓ | ✓ | Carbide for CNC; HSS for manual |
| Stainless steel | ✓ (cobalt) | ✓ | Carbide preferred; cobalt HSS acceptable |
| Aluminium | ✓ | ✓ | HSS works well; carbide for high-volume |
| Cast iron | ✓ | ✓ | Carbide for dry drilling at high speed |
| Hardened steel (>40 HRC) | ✕ | ✓ | Carbide only |
| Titanium | ✓ (cobalt) | ✓ | Carbide with TiAlN coating |
| Plastics / composites | ✓ | ✓ | HSS fine; carbide for abrasive composites |
| Wood / soft materials | ✓ | ✕ (overkill) | HSS |
HSS Grades Explained
- M2 HSS — standard grade, good general-purpose performance
- M35 (5% Cobalt) — better hot hardness and wear resistance; recommended for stainless steel, alloy steel, and interrupted cuts
- M42 (8% Cobalt) — highest cobalt content, maximum hot hardness for tough alloys and high-temp materials
Carbide Drill Coatings
- TiN — general-purpose, extends life in mild steel
- TiAlN / AlTiN — dry drilling steel and stainless at elevated speeds
- TiCN — abrasion resistance for abrasive materials
- Bright (uncoated) — best for aluminium and non-ferrous
Cost Consideration
Carbide drills cost significantly more upfront — often 4–10× the price of equivalent HSS drills. For CNC at high speed, per-hole cost can be lower due to longer tool life. For low-volume, manual, or prototype work, HSS is often more economical.
Quick Decision Guide
- ✅ Choose carbide if: CNC drilling, hardened materials, high volume, tight tolerances, or abrasive materials
- ✅ Choose HSS/Cobalt if: manual drilling, interrupted cuts, older machines with runout, budget-sensitive, or soft/ductile materials
Shop Drills at Tooltec
Browse our full drilling range including solid carbide and HSS/cobalt drills across metric and imperial sizes. Stocked in Perth for fast despatch Australia-wide.