Carbide Grade Overview
Tungsten carbide (WC-Co) grades are the heart of drill bit performance. The right grade balances hardness for wear resistance with toughness for impact absorption.
Key Parameters
- Cobalt content: Higher = more toughness, lower = more hardness
- Grain size: Fine = harder, Coarse (C) = tougher
- Hardness (HRA): Resistance to wear
- TRS (MPa): Transverse rupture strength - impact resistance
Composition & Properties
YG6 (6% Cobalt)
- Hardness: 91-92 HRA
- TRS: 1500-1700 MPa
- Best for: Soft materials, low-impact drilling
- Wear resistance: Excellent
- Toughness: Low
YG8C (8% Cobalt, Coarse)
- Hardness: 89-90 HRA
- TRS: 2000-2200 MPa
- Best for: General masonry, concrete, brick
- Wear resistance: Good
- Toughness: Medium-High
YG11C (11% Cobalt, Coarse)
- Hardness: 87-88 HRA
- TRS: 2400-2600 MPa
- Best for: Reinforced concrete, heavy impact
- Wear resistance: Moderate
- Toughness: Excellent
Grade Comparison Table
| Property | YG6 | YG8C | YG11C |
|---|---|---|---|
| Cobalt % | 6% | 8% | 11% |
| Hardness (HRA) | 91-92 | 89-90 | 87-88 |
| TRS (MPa) | 1500-1700 | 2000-2200 | 2400-2600 |
| Wear Resistance | ★★★★★ | ★★★★☆ | ★★★☆☆ |
| Impact Resistance | ★★☆☆☆ | ★★★★☆ | ★★★★★ |
| Cost | $ | $$ | $$$ |
Application Matching
| Material | Recommended Grade | Reason |
|---|---|---|
| Soft brick, AAC blocks | YG6 | Low impact, high wear |
| Standard concrete | YG8C | Balanced performance |
| Reinforced concrete | YG11C | Rebar impact resistance |
| Granite, hard stone | YG8C | Hardness with toughness |
| Tile, ceramics | YG6 | Precision, low chipping |
Selection Guidelines
- Identify primary material: What will you drill most often?
- Assess impact level: Rotary-only vs hammer drilling?
- Consider rebar risk: Reinforced concrete needs YG11C
- Balance cost vs life: Higher cobalt = higher cost but longer life in tough conditions
Need carbide grade recommendations for your application? Contact our engineering team.
