Performance signs
More force, heat, noise, burrs, and drift often appear before visible catastrophic damage.
Physical inspection
Look for cracks, tooth loss, chipped carbide, blue heat marks, bent plate, damaged shank, or failed welds.
Do not “push through”
Forcing a dull blade increases heat and reduces control.
Method for this decision
- Compare current force, sound, heat, edge quality, and drift with a known-good setup.
- Disconnect power and inspect teeth, carbide, plate, shank, weld, cracks, blue heat marks, and distortion.
- Replace a blade that is damaged or no longer forms chips; do not compensate with extra feed or body force.
Worked example
Example: a blade may still look toothed while a stainless cut begins glazing and wandering. That symptom can indicate dullness or wrong setup, so verify the application before deciding whether replacement or correction is appropriate.
Limits and stop conditions
Wear signs are not a precise remaining-life meter. Different materials and machines fail differently; follow the blade maker’s discard criteria and never keep a cracked, bent, or tooth-damaged blade in service.