Reading tool wear tells you what to adjust before a tool fails mid-cut. The main patterns each point to a cause.
Wear patterns
| Wear type | Looks like | Cause / fix |
|---|---|---|
| Flank wear | Even wear on the edge’s side | Normal; if fast, lower speed |
| Crater wear | A pit on the top face | Heat — lower speed, better coating/coolant |
| Chipping | Small edge fractures | Vibration/interrupted cuts — more rigidity, tougher grade |
| Built-up edge | Material welded to the edge | Too slow / gummy material — faster, better coating |
| Thermal cracking | Comb-like cracks | Heat cycling — steady coolant or run dry consistently |
Some flank wear is normal and predictable — replace the edge before it grows enough to ruin parts. Crater and thermal wear mean too much heat; chipping means too much shock or not enough rigidity; built-up edge means too slow or the wrong coating for the material.
Frequently asked questions
What’s normal tool wear? Gradual flank wear — plan replacement before it grows too large.
What causes built-up edge? Cutting too slowly or the wrong coating in gummy material.
What does chipping indicate? Vibration or interrupted cuts — boost rigidity or use a tougher grade.
Inspect edges under magnification at regular intervals rather than waiting for a bad part — catching wear early lets you swap an edge on your terms, instead of scrapping a near-finished part when a worn tool finally lets go mid-cut.