A nylock nut, also referred to as a nylon-insert lock nut, polymer-insert lock nut, or elastic stop nut, is a kind of nylock nut It is a nut with a nylock collar insert that resists turning.

Rely nylon washers to play a role in the locking nut, called nylon lock nuts, commonly referred to within the industry Nepalese cap. Mainly with threaded screw or bolt connection with the use, after locking nylon ring will be deformed, connecting both ends of the member to fill the gap, and thus play a role in locking.