Locknut
（重定向自Elastic stop nut）
![Nylon lock nuts ('Nyloc')](/Images/godic/202501/10/Nylon_Lock_Nut5213.png")
A locknut, also known as a lock nut, locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque. Elastic stop nuts and prevailing torque nuts are of the particular type where some portion of the nut deforms elastically to provide a locking action. The first type used fiber instead of nylon and was invented in 1931.