Rapid DTH bit wear increases tool costs and drilling downtime. Common causes include abrasive formations, incorrect button geometry, poor flushing, oversized bits, insufficient air, improper operating parameters, worn hammers, and delayed tool replacement.
Every DTH drill bit is a consumable tool, but unusually rapid wear often indicates a problem in the drilling system.
Recognizing common wear patterns can help contractors reduce tool costs.
Gauge Wear
Gauge buttons maintain hole diameter.
Severe gauge wear may be caused by:
- Abrasive formations
- Excessive reaming
- Poor flushing
- Extended use after wear limits
Broken Carbide Buttons
Button breakage can result from:
- Severe impact
- Very hard inclusions
- Incorrect carbide selection
- Excessive operating load
Button Loss
Possible causes include:
- Extreme wear
- Damaged bit body
- Repeated impact loading
- Manufacturing or application problems
Bit Body Erosion
High-velocity cuttings can wear the steel body around the carbide buttons.
Efficient flushing design and appropriate drilling parameters help control erosion.
Slow Penetration with Limited Visible Wear
This may indicate:
- Incorrect bit design
- Insufficient hammer energy
- Poor compressor performance
- Incorrect operating parameters
How to Improve Bit Life
Contractors should:
- Match the bit to the formation.
- Maintain proper airflow.
- Inspect the hammer.
- Monitor gauge wear.
- Avoid drilling excessively worn bits.
- Maintain suitable feed and rotation.
- Record bit performance by formation.
Tool life should be evaluated together with penetration rate.
A cheaper bit that drills slowly or requires frequent replacement may result in a higher cost per meter.
YKDRILL supplies DTH bits and hammers for different rock conditions and drilling applications.
