We have a problem when tightening stainless steel bolts – they tend to seize – whats happening?
Stainless steel can unpredictably sustain galling (cold welding). Stainless steel self-generates an oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding, thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing – the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out. If galling is occurring than because of high friction the torque will not be converted into bolt preload. This may be the cause of the problems that you are experiencing. The change may be due to the surface roughness changing on the threads or other similar minor change. To overcome the problem – suggestions are: 1. Slowing down the installation RPM speed may possibly solve or reduce the frequ
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- We have a problem when tightening stainless steel bolts - they tend to seize - whats happening?
