Turning Roughness Out of Spec: Causes and Improvements
What Out-of-Spec Means
Roughness is not cosmetic - on bearing fits it reduces accuracy and fatigue life.
Common Causes
- Small or worn nose radius: Higher Ra
- High feed: Ra rises with feed squared
- Wrong speed: Too low - BUE; too high - chatter
- Vibration: Long overhang, weak clamping, spindle play
- Material: Gummy material smears
Fixes
- Larger nose radius, keep it sharp
- Lower feed or raise speed to a stable zone
- Shorten overhang, stiffen setup
- Correct fluid to stop BUE
- Even finishing allowance
Inspection
Roughness tester or comparison blocks, with sampling trends.
Huami Practice
Roughness is in first-piece and patrol checks - tool and parameters checked first.