Galling

Encyclopedia : G : GA : GAL : Galling

Galling can occur when metal parts, such as the threads of nuts and bolts, are forced together and rubbing generates friction among the high spots on the surface. The friction causes heat, which is mainly isolated to these small high spots. The high spots weld together but further displacement causes these tiny welds to break, which makes the surface even rougher, creating more opportunity for friction. Not to be confused with cold-welding.

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