Q: I’ve heard of thread galling but am not exactly sure what it is. Can you explain?
A: Galling happens when a bolt is over-tightened and the threads seize together creating what we call a “cold weld”. The friction from fastening actually causes the threads to heat up and the bolt to bond to the nut or fastening material. Once galling takes place it is irreversible; meaning the only way to separate the bolt is to break it or the nut.