The Effects of Stress on the Corrosion of Scaffolding,
Cranes, and Wire Ropes

Scaffolding brackets often fail in zones
of high stress. Often this zone is hidden
behind a bolt and cannot be inspected without
dismantling the structure that is supported by
the bracket.

It is widely known that the process of corrosion is accelerated under stress. This leading cause of failure is termed "stress corrosion" by engineers and scientists. Inspection of the failed scaffold bracket shows extensive metal loss due to corrosion on all its surfaces but specifically, the point of failure was at the wedge bolt-slot, where point of highest stress in the scaffold bracket is located. At that spot, the steel that supports the bracket and the load it supports was sheared off leaving a gap behind.

A competent person would have scrapped this scaffold bracket solely by visual inspection because the corrosion was obvious and generally widespread on the entire surface of the scaffold bracket. But, specifically, he would have inspected the wedge bolt-slot for stress corrosion by removing the oxide scale (rust) and inspecting the substrate metal for residual metal thickness and for cracks.