The top lock nuts are manufactured from low-carbon steel to meet Grade A performance specifications. These kinds of prevailing torque lock nuts are designed for use in non-critical applications with Grade 2 or Grade 5 hex bolts, or other customized bolts. 

The lock nuts can be supplied with various of finishes or customer-specific coatings.

There are many kinds of hex top lock nut.
Prevailing torque differentiates a locknut from a free spinning nut based on a value of how much torque is required during installation before clamp loading. For example, on a nylon-insert nut, it is the torque needed to overcome the resistance of the nylon dragging across the mating thread. This torque value is usually not very high relative to final installation torque. Tolerance ranges for torque are specified in some standards such as (ISO, DIN, IFI, ASME, SAE, AN-, MS-, NAS- NASM-). We attach the torque table below in specification.

A lock nut is a kind of nut which resists loosening when properly threaded onto a bolt. Nut and bolt fasteners are much common in industry and home applications. Many are universal in application, while others work best under certain circumstances.

We also have nylock hex nut, and other kinds lock nuts.

Lock nut is widely used in machinery and other industries.