This zinc-plated hex nut is made of heat treated steel and has a nylon-filled collar at its back end. When a screw reaches the collar, the threads and nylon form a tight, frictional fit, restricting movement of the screw when it is subjected to vibration. Common structural applications include engines, turbines, hydraulic cylinders, railroads and aerospace. For use with Class 10 bolts with a minimum tensile strength of 1040 square N/mm as well as in temperatures of 250 degrees (F) or below. (MNLN16C10)