When to Sharpen Carbide Button Bits: The Wear Signs That Matter
The Bit Brief · Maintenance & Wear
The expensive time to sharpen a button bit is often after it has been overdrilled. Regrinding works best as a planned maintenance decision, not a last attempt to rescue a bit that has already suffered serious damage. Knowing the early warning signs helps a crew keep replacement purchases under control.
The wear-flat rule
A wear flat is the flattened area developing on the top of a cemented-carbide button. As it grows, the bit may require more energy to penetrate the formation. Sandvik advises resharpening before the wear flat reaches about half the button diameter. Epiroc guidance also discusses establishing more conservative intervals around one-third, depending on use and grinding strategy. Follow the OEM and site-specific method rather than treating a single threshold as universal.
Look for these additional clues
- Gauge wear or anti-taper: The outer row loses geometry, which can affect clearance and hole size.
- Snakeskin microcracking: Fine surface fatigue cracking may appear even before there is major flat wear.
- Falling penetration rate: A worn button profile is one possible cause, after other drilling conditions are checked.
- Chipped or fractured inserts: Stop and assess damage rather than treating it as routine cosmetic wear.
- Uneven face wear: Irregular wear may indicate setup, drilling parameters or a formation-specific problem.
How to run a useful inspection
At a planned stop, clean the bit according to site safety procedures, photograph the face and gauge, record the make and diameter, and compare the visible wear with OEM criteria. An inspection record that includes footage and drilling conditions is stronger than a vague note saying “bit getting dull.”
Do not measure by eye alone where accurate wear limits matter. Use a consistent gauge or trained inspection method appropriate to the bit. A photo can help DG Carbide discuss the likely service path, but a final decision may require the tool in hand.
When a bit needs more than sharpening
Sharpening primarily restores a worn button profile. Missing buttons, body deterioration or substantial gauge loss can require a broader refurbishment assessment, button replacement or complete retirement. An attractive polished face does not prove structural safety.
Schedule before the job is urgent
Plan work around batch changes rather than waiting until every bit is dull at once. A small stock of ready-to-run bits and a predictable inspection schedule can be more helpful than rushing replacements at peak workload.
Read our refurbishing service overview, or ask DG Carbide about a worn-bit assessment. We are based in Saugerties, NY, with nationwide mail-in inquiries for compatible carbide button rock-drilling tools.
Frequently asked questions
What does a flat carbide button mean?
It is a wear surface on the button face. Its size and associated wear pattern help determine whether scheduled resharpening is due.
Is a slower bit always dull?
No. Formation, flushing and drilling settings can change penetration. Inspect the bit alongside those other causes.
Continue researching
- Drill Bit Refurbishment vs. Replacement: How to Make the Right Call
- How Carbide Button Bit Sharpening Works: From Inspection to Return
- Gauge Wear and Anti-Taper on DTH Bits: Why the Outer Buttons Matter
See DG Carbide's related service or send your bit details for an assessment.
Before you buy another bit, ask DG Carbide.
Sharpening, refurbishment and eligible carbide button replacement from Saugerties, New York. Serving local contractors and accepting nationwide mail-in inquiries for compatible bits.
Technical decisions depend on the bit maker's limits, equipment conditions and inspection. Savings examples are illustrative and are not DG Carbide pricing or customer results.
Technical references: Sandvik rock-tool resharpening guidance · Epiroc grinding equipment and wear guidance. Follow the guidance for your specific bit and equipment.