Tool wear

Tool wear is the gradual degradation of a cutting tool's edge from the heat and mechanical stress of cutting, which progressively reduces cutting performance and, past a certain point, part accuracy and surface finish. It accumulates over the life of a tool and is one of the reasons cutting parameters are chosen conservatively rather than at their theoretical maximum.

Why tool wear is a cost trade-off, not just a maintenance issue

Tool wear is managed as a cost trade-off: cutting more aggressively removes material faster per pass but wears tools out sooner, so the cheapest overall strategy balances cycle time against tool replacement frequency, not just raw cutting speed.

Where tool wear shows up

Not on the drawing; it's a production-floor and programming concern, though a tight tolerance or fine finish requirement can indirectly force more frequent tool changes to keep wear within acceptable limits.

Common mistakes

Running a worn tool past its practical life to avoid a tool change, risking an out-of-tolerance or poorly finished part that costs more to rework than the tool change would have.

What causes tool wear?

Heat and mechanical stress at the cutting edge, accumulating with cutting time, speed, feed and material hardness.

How is tool wear typically managed in production?

By tracking tool life against expected wear (by cutting time or part count) and replacing or regrinding tools before wear affects part quality.

Does tool wear affect cycle time estimates?

Yes, an estimate that ignores tool-change time and frequency can understate total production time for longer runs.