The Hillman Group 4359 1/2-20 Stainless Steel Stop Nut (Nylon Insert) (3-Pack)<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Nylon Insert Lock Nuts have a captive undersized nylon washer that creates friction with the mating threads to prevent loosening</li><li>Helps resist the effects of vibration and other forces</li><li>Stainless steels are used for their corrosion resistance， high-temperature strength， scaling resistance and low-temperature toughness</li></ul></div><img src="http://ecx.images-amazon.com/images/I/51-tjAu92qL.jpg" noproxy>