HILLMAN 1/4-20 in. Zinc-Plated Steel USS Nylon Lock Nut 100 pk

Zinc-Plated Nylon Insert Stop Nuts are ideal for securely fastening a bolt when connecting materials. Use these hexagonal nuts with bolts and washers of the same material, finish, and grade. The nylon ring inside the nut 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.