Long-term reliability effects of surface roughness

Quantify the influence of shaft surface roughness on the long-term reliability of angle-grinder spindle-shaft and needle-roller-bearing subsystems.

Background

The case study found no detectable influence of surface roughness on the measured functional behavior within the investigated parameter range, so roughness was excluded from the immediate inspection criterion. However, the experiments did not establish whether roughness variations affect long-term reliability, leaving this issue unresolved for the functional evaluation of used spindle shafts.

References

However, a potential influence on long-term reliability cannot be excluded based on the present data and therefore remains subject to future investigation.

— Unified Embodiment Description for functional evaluation of used components in circular manufacturing systems  (2608.16206 - Hemmerich et al., 17 Aug 2026) in Section 4.7, Step 7: Definition of functionally derived tolerance regions