Metallics JNYN166SS Nuts 1/2-13 Hx Ny-Ins Locknut SS (Jar 50)

It is a 1/2-13 nut, meaning 1/2 inch nominal diameter with 13 threads per inch, which is the standard UNC coarse pitch for 1/2 inch rod. Threads are cut to ANSI/ASME B1.1, so it runs onto standard 1/2-13 all-thread, hanger rod, or bolts. It will not fit 1/2-20 fine thread.

No. The nylon insert does the work a lockwasher would, gripping the bolt threads to resist loosening, so the JNYN166SS is used on its own. Metallics lists it for areas of high vibration and for electrical, plumbing, and heating and air conditioning work, which is exactly where a plain hex nut backs off.

No. The JNYN166SS is flagged as not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. If your contract carries domestic sourcing requirements, you will need a domestically produced nut instead.

The nut is 18-8 stainless steel, the general-purpose austenitic grade used for wet and outdoor service, so it holds up in damp mechanical rooms, rooftop equipment, and exterior strut runs. For saltwater or heavy chloride exposure, 316 stainless is the step up.

Across the flats the nut measures 0.736 to 0.752 inch, which takes a 3/4 inch wrench or socket. Overall height across the nut runs 0.579 to 0.609 inch. Note the nylon ring sits above the metal threads, so allow for that when figuring rod stick-out.

Yes. Dimensions conform to ASME B18.16.6, the standard covering prevailing-torque (nylon insert) hex lock nuts, and the threads to ANSI/ASME B1.1. Hardness is listed at Rockwell B95-C35. That combination is what a submittal reviewer looks for on a hex nylon insert locknut callout.

Each jar holds 50 nuts, and the order minimum is 50 each, so one jar is the smallest buy. Metallics notes other sizes and quantities are available by request if you need a different count or thread size.

The locking element is nylon, which limits the service temperature well below what the 18-8 stainless body alone could handle. For hot work near flues, boilers, or steam lines, use an all-metal prevailing-torque or jam nut arrangement rather than a nylon insert nut. The stainless body itself is listed for electrical, plumbing, and heating and air conditioning service.

Reuse is limited. The nylon ring deforms around the bolt threads the first time it is run on, so holding torque drops with each removal. For maintenance work where the joint gets opened repeatedly, plan on fresh nuts, which is one reason the JNYN166SS ships 50 to a jar.