HSS Material Grades Comparison Chart
Understanding HSS grades is critical for importers. The "Standard" black drill bit can be made from vastly different materials. Here is the chemical and performance breakdown:
| Grade | W (Tungsten) | Mo (Molybdenum) | Co (Cobalt) | Hardness (HRC) | Typical Use |
|---|---|---|---|---|---|
| HSS 4241 | 1.5% | 0.8% | - | 60-62 | DIY Wood, Plastic, Aluminum |
| HSS 4341 | 2.0% | 2.8% | - | 62-63 | Soft Steel, Iron (Light Duty) |
| HSS 9341 | 3.0% | 3.0% | - | 63-64 | General Metal Drilling |
| M2 (6542) | 6.0% | 5.0% | - | 64-65 | Industrial Standard (Steel/Iron) |
| M35 | 6.0% | 5.0% | 5.0% | 66-67 | Stainless Steel, Hard Metal |
The "Roll Forged" Grades: 4241 & 4341
These grades are primarily used for Roll Forged manufacturing processes. They contain less Tungsten and Molybdenum, making them softer but much cheaper.
- HSS 4241: The cheapest HSS. Great for DIY sets sold in supermarkets. If you try to drill Stainless Steel with this, the tip will burn immediately.
- HSS 4341: A slight upgrade. Can handle thin gauge mild steel, but lacks the heat resistance for continuous professional use.
The Industrial Standards: M2 & M35
For professional/industrial markets (Fully Ground bits), these are the required standards:
- M2 (AISI 6542): The global workhorse. Balanced toughness and hardness. Suitable for 90% of metalworking tasks.
- M35 (Cobalt 5%): The "Stainless Steel Killer". The addition of Cobalt raises the heat resistance significantly. Critical for drilling materials with low thermal conductivity (like stainless).
Cost vs. Performance Selection for Importers
If you are sourcing for...
- Determine your Market:
- Price-Point Retail: Stick to 4241/4341 Roll Forged. Volume is key.
- Hardware Stores / Prosumer: M2 Fully Ground is the minimum entry point.
- Industrial Supply: M35 is mandatory. M42 is a niche upsell.
- Check the Weight: M2 steel is denser than 4241. A simple weight check can sometimes reveal "fake" material claims.
- Ask for Hardness Tests: Always request a random sample HRC test report with your shipment.
