Nut, hex, nyloc, olive dipped, GR 4.8, STD, 6 x 1 mm, Fastbolt.

A nyloc nut, also referred to as a nylon-insert lock nut, polymer-insert lock nut, or elastic stop nut, is a kind of locknut with a nylon collar that increases friction on the screw thread. Olive-Drab produces a heavy olive drab chromate coating on zinc or cadmium plated surfaces. It provides the maximum salt spray and abrasion resistance of any type of chromate dip.