Short answer: Bit life is set by how abrasive the laminate is: standard FR4 on carbide runs hundreds to about 1,000 hits, ceramic-filled M9 drops to 100-200 hits, while PCD or alumina-grade tools last over 50x a carbide bit. Nano-ceramic AlN CCL is especially brutal — only 32-41 percent of the life you get on a PTFE board. Choose the tool to the laminate, then protect it with a stable stack.
Number: FR4 on carbide gives hundreds to ~1,000 hits; ceramic-filled M9 gives 100-200 hits; PCD/alumina tools exceed 50x carbide life; nano-ceramic AlN CCL drill life is only 32-41 percent of a PTFE board (tshztech, gopcba).
Boundary: Bit life is owned by the laminate abrasiveness and the tool; the entry/backup board stabilizes the workpiece but does not set life. Always qualify bit cadence on the actual laminate.
"How long does a drill bit last?" has no single answer — it depends entirely on what you are cutting. Ceramic-filled laminates are far harder on a bit than FR4.
Life by laminate
| Laminate | Tool | Typical life |
|---|---|---|
| FR4 | Carbide | Hundreds to ~1,000 hits |
| Ceramic-filled M9 | Carbide | 100-200 hits |
| Ceramic (any) | PCD / alumina | >50x carbide |
| Nano-ceramic AlN CCL | Carbide | 32-41% of PTFE-board life |
What to do with this
- On FR4, a carbide bit is fine; track hits and replace on schedule.
- On ceramic-filled or AlN, move to PCD/CVD diamond and accept the cost — it is cheaper than scrap.
- A flat, rigid backup keeps the bit from deflecting and chipping prematurely.
For tool selection detail see the ceramic drill-bit selection page and for the no-chipping process the ceramic substrate page.
