1) All bushes are 100% inspected and no failures were recorded, either by physical testing or visually.
2) Unassembled bushes show no sign of patchy passivation.
3) Post treatments handling or further process could have a detrimental effect on the passivate, namely the tape used to mask the bush head prior to top coat paint application ot certain types of coolant/compound used during boring/lapping hence the concentartion around the main bore