Metallics JHHN38 Nuts 3/8-16 Hvy Hx Nut St-zn (Jar 100)

Grade 2 steel, with hardness listed at Rockwell B68 to C32. Grade 2 is the general purpose grade and is matched to Grade 2 bolts and rod for ordinary hanging and support work. If your drawing calls for Grade 5 or Grade 8 mating hardware, or specifies a structural connection, this nut is not the right match for it.

No. The JHHN38 is listed as not Buy American compliant and not ARRA compliant, with country of origin shown as multiple. On a federally funded or Buy America specified project you will need a domestically sourced heavy hex nut instead.

A heavy hex nut is wider across the flats and thicker than a finished hex nut of the same thread, so it spreads load over more bearing area and gives more thread engagement. On the JHHN38 the flats measure 0.669 to 0.688 inch and height runs 0.341 to 0.377 inch. Use it where you want a larger bearing face against strut, channel, or a washer; a standard hex nut is fine for light trim work and fits a smaller wrench.

The JHHN38 is steel with a zinc finish, which handles indoor and normally dry or occasionally damp conditions. Zinc plating is a sacrificial coating, not a marine-grade one, so for constant wet exposure, corrosive wash-down areas, or coastal work step up to hot dip galvanized or 18-8 stainless in the same 3/8-16 heavy hex pattern.

They ship in a jar of 100 pieces, and the jar is the order minimum, so 100 is the smallest buy. Shipping weight on the jar is 2.86 lbs. Metallics notes other sizes and quantities are available by request if 3/8-16 is not the size you need.

Metallics lists the JHHN series for electrical, plumbing, heating and air conditioning work. In practice that is rod hanging, strut and channel assemblies, pipe and duct supports, and anchor work where a 3/8-16 thread is in play and you want a wider bearing face than a finished hex nut gives.