An assortment of zinc-plated nylon insert stop nuts from Hillman. Nylon insert stop nuts are hexagonal nuts used with bolts and washers of the same material, finish, and grade. The interior nylon ring creates rotational resistance when displaced by a mating male threaded fastener, thus preventing loosening. The nylon insert also helps resist vibration and adds extra corrosion resistance. This assortment features variants running #6-32 thru 1/2"-13 including both fine and coarse thread sizes. Full assortments of #595 contain fourteen (14) refills comprised of Hillman item numbers #596 - #609.