Core Takeaway: In bored piling and pile foundation engineering, selecting the right piling tools dictates construction efficiency and project costs. For medium-soft to weathered rock formations, highly wear-resistant bullet teeth (such as the B47K22) are highly recommended. However, when confronting extreme hard rock or complex strata, foundation drilling roller cutters (single cone bits) are the definitive choice for breaking through the rock barrier.
1. Rotary Drilling Bits / Drill Teeth (Bullet Tooth)
The bullet tooth is the most frequently used cutting tool for rotary drilling rigs, primarily designed for cutting through soil, gravel, and medium-hard rock.
Classic Model: The B47K22 is one of the most widely applied models in the industry, offering exceptional penetration capabilities.
Material Requirements: Premium rock teeth typically utilize a tungsten carbide insert combined with a high-strength alloy steel body to maintain a sharp cutting edge under severe friction.
2. Foundation Drilling Roller Cutter (Roller Bit)
When encountering hard rock formations where traditional drill teeth suffer from rapid wear, roller cone cutters become essential.
Working Principle: They fracture the rock through rotational squeezing and impact at the bottom of the drill head, functioning as a highly effective rock bit.
Application Scenarios: Widely utilized in large-diameter bored drilling, they effectively conquer geological formations with extremely high compressive strength.
3. Technical Comparison: Bullet Tooth vs. Roller Bit
| Comparison Dimension | Bullet Tooth (Rotary Drilling Bits) | Roller Bit (Roller Cone Cutters) |
| Applicable Formations | Clay, sand, weathered rock, soft to medium-hard rock | Extreme hard rock, granite, quartzite |
| Rock Breaking Method | Cutting, gouging | Squeezing, impacting, crushing |
| Primary Advantages | Fast drilling speed, lower cost, easy to replace | Superior rock-breaking power, high-temperature resistance |
| Maintenance Notes | Requires regular inspection of the tooth holder | Must be used with high-quality bearings and seals |
Frequently Asked Questions (FAQ)
Q: My project involves standard Bored Drilling; which tools should I choose?
A: It depends on your geotechnical report. For conventional soil, standard drill teeth are sufficient. If the strata contain hard rock layers, we recommend customizing your rotary drill bucket with roller cone cutters.
