ABSTRACT
When we tighten a fastener, we pump energy into it: tension, torsion, and bending energy.
The fastener is a stiff spring, and we stretch, twist, and bend it.
After we let go, this energy is held in the fastener by friction constraints in the threads or
between contact faces of the nut and joint. If something overcomes or destroys these friction
forces, the energy stored in the fastener will be released; the bolt will return to its original
length with the inclined plane of the bolt threads pushing the inclined plane of the nut threads
out of the way.
