Fretting
| Application | Tilt tray sorter chain used in the baggage handling area of a major airport. |
| Failure mode | Chain pins and bi-planar block show scoring and heavy red deposit indicating fretting corrosion. |
| Diagnosis | Fretting corrosion caused by marginal lubrication, where the lubricant present is insufficient to prevent the asperities on each component rubbing together. |
| Solution | Every pin should be removed and all traces of abrasive red oxide removed. The chain should then be operated in an improved lubrication regime. |