Galling
| Application | Hollow pin (step pin) used in a high rise escalator. |
| Failure mode | The pin pressure faces have suffered from severe galling where the surfaces have articulated and fused together. |
| Diagnosis | The very high pressures experienced by these high rise escalators have led to squeeze-out and failure of the lubricant allowing the surfaces to touch and gall when the chain articulated. |
| Solution | Use high quality, high pressure lubricants and ensure that the lubricant regime is such that the film of lubricant is constantly maintained between the surfaces. |