I have one of those small LED pocket torches (flashlight). To turn it on
and off, I have to screw the end up towards the bulb end to compress the
contacts against the battery.

The thread in the screw end is an extremely 'loose' fit and tends to
'unscrew or scew up' when it sits in the car glove compartment for a while.

Is there a way to *stiffen* this 'loosness' in the thread, without reducing
the electrical conductivity?

It needs to make good electrical contact for the torch to work, so I guess
that rules out putting a dab of wood glue on the thread? Thanks for any
advice.