Dimensional tolerances define allowable deviations, but surface finish determines whether those tolerances hold up in real-world applications.
- Rough surfaces can prevent proper seating, causing misalignment, stress concentration, and premature wear.
- Critical components like bearings, seals, and gears demand fine finishes to maintain tight tolerances under operational loads.
- Post-machining treatments (e.g., heat treatment) may introduce distortion, making final finishing essential for restoring dimensional accuracy.
In short, surface finish directly influences the achievable tolerance band, and overlooking it can compromise the reliability of the entire assembly.
