Hex and square nuts are the most commonly ... The jam nut is a thin nut, normally used under a full nut to develop locking action. Recommended practice is to torque the jam nut to seat only ...

If you have a metal lathe just looking for some work, why not make your own lock nuts? That’s what [my mechanics insight] did when faced with a peculiar lock nut that needed replacing in a car.

Definitely. A jam nut is a thinner-than-average nut tightened against a standard-height nut to lock the two nuts in place. Installed correctly, a jammed nuts resist loosening due to vibration ...