Metallics JSHC516134 5/16-18 x 1-3/4 in. Socket Head Hex Cap Screws - Alloy Steel Black - Each

It's a 5/16-18 UN thread at 18 threads per inch, so it threads into any standard 5/16-18 UNC tapped hole or nut. Shank length is 1-3/4 inches. Dimensions follow ASME B18.3-2012, the inch socket cap screw standard, so head geometry matches what a counterbore drilled to that standard expects.

The alloy steel socket head cap screw rates 180,000 psi minimum tensile and 162,000 psi minimum yield, higher than equivalent sizes of Grade 5 or Grade 8 hex head cap screws, and it does it in less bearing surface because the drive is internal. Hardness is Rockwell C39. For structural brackets, machine mounting, and equipment anchoring where a hex head won't fit the pocket, this is the swap.

No. The JSHC516134 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your project carries a domestic-sourcing clause, this part won't satisfy it and you'll need a documented domestic fastener.

It takes a hex (Allen) key, not a wrench on the outside of the head. Socket depth is 0.151 inches. Drive type is hex and head type is socket, so you'll want a good-quality key or hex bit socket fully seated before torquing, since at Rockwell C39 hardness the fastener will outlast a worn key.

They ship in a jar of 100 pieces, and 100 is the order minimum. Jar weight is listed at 4.36 lbs. Other sizes and quantities are available by request if 1-3/4 inch length doesn't suit the job.

The finish is black on alloy steel, which is a plain oxide-type appearance rather than a corrosion barrier like zinc or stainless. Treat these as indoor or protected-location fasteners for electrical, plumbing, and HVAC work. For exposed exterior or wet mechanical rooms, specify a zinc-plated or stainless socket cap screw instead.