How to Choose the Right Auger Tooth? Earth Teeth vs. Rock Teeth
26 November 2025
The performance of a hydraulic auger depends on the sharpness of its teeth and their suitability for the ground structure. Wrong tooth selection not only slows down the work but can also burn the auger motor.
At HKM, we offer W Series teeth designed specifically for every ground condition. So, which one is right for your site: W2, W3, or W4?
1. Tooth Types and Applications
Tooth structure and material change according to ground hardness:
- W2 - Soft Rock: Designed for soil, clay, sandstone, and soft limestone. With its wide structure, it digs quickly and ejects the material.
- W3 - All Ground: The "Joker" tooth for variable ground conditions. Performs well in both soil and gravelly, medium-hard grounds.
- W4 - Hard Rock: Has a reinforced diamond (tungsten carbide) tip. Used for drilling asphalt, concrete, frozen ground, and hard rock. It progresses by grinding the ground.
2. Technical Comparison Table
Which tooth to use where?
| Model | Tungsten | Ground Type | Feature |
| W2 | No | Soft Rock / Soil | Fast Digging |
| W3 | Yes (Tip) | All Ground / Mixed | Versatile Use |
| W4 | Yes (Full) | Hard Rock | Diamond Breaking Tip |
3. Is It Time to Replace?
If the auger spins but doesn't dig, check these parts:
- Pilot Bit (Fishtail): The centering bit at the very tip. If dull, the auger cannot penetrate and spins in place.
- Pins and Locks: If the pins holding the teeth loosen, teeth will fall out, damaging the auger body (flight).