Nylon lock nut is a round nut, and in its outer open four small slot, you can use the crescent wrench screw on the stud, the lock nut should be equipped with a shaft Washer, it can be used to make the small groove on the stud and its peripheral groove relative to the fixed, to prevent its loose.</br> Bolt thread on the nuts embedded in the nylon extrusion, making the nylon deformation, after installation, the nylon and thread completely squeeze contact, the extruded nylon to the bolt A lot of resilience, increased friction, so that the bolt is not easy to loose.