Metallics JNYN166G Nut 1/2-13 Hx Ny-Ins Locknut Galv (Jar 50)

It's a 1/2-13 nut, meaning a 1/2 inch nominal diameter with 13 threads per inch, which is the UNC coarse thread for that diameter. It will run onto any 1/2-13 bolt, rod, or threaded stud, including 1/2 inch coarse all-thread used for hanging electrical and mechanical supports.

Nylon insert. The JNYN166G is a hex nylon-insert locknut, so the resistance comes from an unthreaded nylon collar in the top of the nut that the bolt threads cut into. That gives you vibration resistance without a separate lock washer. Because the locking element is plastic, it is meant for ambient-temperature service and is best treated as a one-time-use fastener rather than something reused repeatedly.

The nut body is galvanized, so it has a zinc coating for general corrosion resistance and handles damp interior work, unheated spaces, and sheltered exterior use. For direct saltwater exposure or continuous wet service, stainless would be the better call. Keep in mind the nylon collar limits it to normal ambient temperature ranges.

Fifty nuts per jar. Metallics packs this 1/2-13 locknut in a jar rather than a loose bulk box, which is what you want on a service truck or a gang box where loose hardware ends up on the floor. One jar covers 50 connection points.

Order Metallics part number JNYN166G. That designation covers the 1/2-13 hex nylon-insert locknut in galvanized finish, packed 50 to a jar. There is a single model under that number, so no finish or pack suffix needs to be specified.

Yes, that's the point of the nylon collar. The insert grips the bolt threads and resists backing off under vibration, so you don't need to stack a split lock washer under it on 1/2 inch threaded rod or strut hardware. Use a flat washer if you need to spread load across a slotted channel or a soft surface, since the locknut itself does nothing for bearing area.