Locking Nuts

There are many kind of nuts.
When your application is subject to vibrations and torque, nuts can loosen.
There for it is best to use locking nuts
Locking nuts are nuts that resist loosening under vibrations and torque.

Auto-Lok Nuts - Double slotted self locking nut Auto-Lok Nuts
SNEP self locking nuts SNEP nut - Single slotted nut H=D SNEP nut - Single slotted nut H=1.3D SNEP
Simmonds nuts Simmonds nut - PH105 Simmonds self-locking nuts
Tight Secure Fasteners TSF - Ring lock washers Tight Secure Fasteners
Tight Secure Fasteners TSF - Ring lock washers Other locking nuts