Metallics JSHC516212 5/16-18 x 2-1/2 in. Socket Head Hex Cap Screws - Alloy Steel Black - Each

Yes. The Metallics JSHC516212 alloy steel socket head cap screw is rated at 180,000 psi minimum tensile and 162,000 psi minimum yield, which is above what equivalent-size Grade 5 or Grade 8 hex head cap screws provide. Because it is internally wrenched with a hex key rather than turned by a wrench on the head, it also needs less clearance around the head. Hardness is Rockwell C39.

Size the counterbore off the head: the head measures 0.457 to 0.469 in. across and 0.306 to 0.312 in. high on this 5/16-18 screw. A counterbore a little over 0.469 in. diameter and at least 0.312 in. deep lets the head sit flush or below the surface. The screw is made to ASME B18.3-2012, so those head dimensions follow the standard socket head cap screw series.

Yes. The thread is 5/16 with 18 threads per inch in the UN form, which is standard 5/16-18 UNC. It mates with any 5/16-18 tapped hole, nut, or strut channel nut. It will not fit a 5/16-24 fine thread.

No. The JSHC516212 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. For a federally funded job with domestic sourcing requirements, you will need a domestically produced socket head cap screw instead.

It takes a 1/4 in. hex key. The head is a socket type with a hex drive, with 0.151 in. of key engagement depth, so a full-length hex bit or key seats properly without camming out. There is no external wrenching surface, so you need the key, not a socket wrench.

They ship in a jar, with a minimum order quantity of 100 pieces. That is the buying unit, so plan on a full jar rather than loose counts if you only need a handful for one bracket.

The material is alloy steel with a black finish, which is a bare or oxide-type finish rather than a plated corrosion coating. It is intended for electrical, plumbing, and HVAC work in dry or protected interior locations. For wet, exterior, or washdown areas, choose a plated or stainless socket head cap screw.

At 2-1/2 in. long on a 5/16 diameter, it is well past 3 times the nominal diameter, and screws at or above 3D are subject to tensile strength, yield strength, elongation, and reduction of area testing. Elongation is 10 percent minimum and reduction of area 33 percent minimum on machined specimens. That matters if you are specifying fasteners for a structural or seismic bracing detail.

Order it as Metallics JSHC516212, part of the SHC socket head cap screw series. Metallics offers other diameters, lengths, and pack quantities in the same series on request if 5/16-18 x 2-1/2 in. is not the size you need.