Bad threads, and repair procedures, right. Broken studs and stripped threads are not always the product of the overzealous neophite. Several factors cause thread damage: Wear from repeated assemblies ...

Inserts are classified as two general types: those held in place by external threads and those that use some means other than threads (knurls, grooves, interference fit) for their holding power.

We have all done it, overtightened a bolt and blown out the threads. When a bolt starts to tighten up and then go suddenly loose, you know that the threads are toast and now you have a problem.