Metallics JG5HC20 Bolts 5/16-18 x 4 G5 HXBT St-zn (Jar 50)

It's a 5/16-18 coarse thread bolt, 18 threads per inch, with a measured shank diameter of 0.3065 to 0.3125 inch. Across the flats the hex head runs 0.489 to 0.500 inch, so a 1/2 inch wrench or socket drives it. Head height is 13/64 inch, with 0.14 inch of wrenching height on the flats.

Bolts only. The jar contains 50 hex bolts, no nuts and no washers, so add 5/16-18 hex nuts and 5/16 flat or lock washers to the order if the connection needs them. Thread is standard 5/16-18, so any off-the-shelf nut in that size mates with it.

No. The JG5HC20 bolts are not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. If your contract carries a domestic sourcing clause, these will not pass, and you'll need a domestically produced Grade 5 bolt instead.

The finish is zinc plating over steel, which is a general purpose indoor and sheltered-outdoor coating. It handles mechanical rooms, equipment pads and truck work fine. For constant wet exposure, coastal air or direct ground contact, go to hot dip galvanized or stainless instead, because plated zinc is thin and will eventually rust through at scratches and cut threads.

No. They ship as a jar of 50 pieces, and 50 each is the order minimum, so that's the smallest quantity. Metallics does list other sizes and pack quantities in the G5HC and JG5HC series by request if 50 of this length isn't what you need.

Head geometry follows ASME B18.2.1-2012, the standard hex bolt dimension spec, so the 0.489 to 0.500 inch head width and 13/64 inch head height are to spec and will clear counterbores and sockets sized for a standard 5/16 hex bolt. Steel is in the AISI 1008 to 1026 range.

Yes, Metallics lists the G5HC and JG5HC Grade 5 hex bolts for the electrical, plumbing, heating and air conditioning trades. Typical use is hanging or anchoring equipment, strut and bracket connections, and bolting motors to bases where a plated medium carbon steel bolt is acceptable.