Nylock Nut

Locknuts, also known as a prevailing torque nuts, stiff nuts, or elastic stop nuts resist loosening caused by machine vibrations and torque. They are commonly used by machinists, engineers, and mechanics, and there are two general types of locknuts: prevailing torque and surface bearing . These are free spinning nuts that require tightening against a bearing surface in order for the locking mechanism to work. This type is not recommended for use on fragile parts. A few common types of free spinning lock nuts include: serrated flange, spring head, and surface-bearing