High air pressure DTH (Down-The-Hole) bits are widely used in deep rock drilling, but they can fail prematurely if working conditions or parameters are not optimized. Here are the main reasons:
1️⃣ Excessive or unstable air pressure Overpressure causes abnormal impact frequency and uneven energy transfer, leading to early tooth cracking or surface fatigue. 👉 Solution: Keep working pressure stable, typically between 18–30 bar depending on the rock type.
2️⃣ Rock hardness beyond design range Drilling in very hard or quartz-rich formations accelerates wear or tooth breakage. Solution: Use carbide buttons or bits designed for hard rock.
3️⃣ Poor cooling or air circulation Blocked airways lead to overheating and loss of surface integrity. Solution: Clean and maintain air channels regularly.
4️⃣ Misalignment of drilling system If the drill string or guide is not properly aligned, the bit may wear unevenly or fracture. Solution: Ensure concentricity between the bit and drill rod.
5️⃣ Insufficient lubrication or dirty air Moist or dusty compressed air increases internal wear. Solution: Use clean, dry air with a water separator and apply thread grease regularly.
6️⃣ Incorrect drilling parameters Improper balance between thrust, rotation speed, and impact frequency can shorten bit life. 👉Solution: Adjust drilling settings based on formation type.
In summary: The main causes of failure in high-pressure DTH bits are impact overload, abrasive wear, and thermal fatigue. Proper air pressure control, bit selection, and good maintenance are the keys to longer service life.
👉 We specialize in DTH, Top Hammer, and Tricone bits for mining and construction drilling. Welcome to connect and exchange technical experience.
