Metallics JBRHC15 Bolts 5/16-18 x 2-1/2 HXBT Br (Jar 100)

It's a 5/16-18 bolt: 18 threads per inch, with a measured outside diameter of 0.3065 to 0.3125 inch. That's standard 5/16 coarse (UNC) thread, so it mates with any 5/16-18 nut or tapped hole. Overall length is 2-1/2 inches.

Solid brass. The material is listed as brass and the head color as brass, not a plating over steel. That matters for grounding and bonding work, where electricians want brass or bronze hardware for conductivity and corrosion resistance rather than a plated steel bolt that will rust out in a damp vault or outdoor enclosure.

The JBRHC15 is flagged compliant for both Buy American and ARRA. Country of origin is China, so if your specification requires domestic melt and manufacture rather than the ARRA/Buy American compliance flag, verify against the exact clause in your contract documents before you submit.

The hex head measures 0.489 to 0.500 inch across the flats, so a 1/2 inch wrench or socket is the right size. Head height is 13/64 inch, with 0.14 inch of wrenching height, so keep that in mind if you're working in a counterbored or recessed spot.

They come 100 to a jar, and 100 count is the order minimum, so the jar is the smallest unit you can buy. Other sizes and quantities are available by request if 5/16-18 x 2-1/2 or a 100-piece jar isn't what the job needs.

Brass hex bolts like the JBRHC15 go where a steel fastener would corrode or where you need a conductive, non-magnetic connection: ground bus and ground plate mounting, bonding jumpers, cable lug terminations, switchgear and transformer connections, and damp or outdoor enclosures. Brass is softer than steel, so torque it to the lug or bus manufacturer's figure rather than pulling it down like a structural bolt.

The 2-1/2 inch length is measured under the head, so subtract your nut and washer stack from that to get usable grip. Practically, it handles a combined material thickness up to roughly 2 inches with a nut and a couple of washers left over. For thinner single-plate work a shorter 5/16-18 is the cleaner choice, and Metallics offers other lengths in the JBRHC series by request.

No. The jar holds 100 hex bolts only. Brass nuts and brass washers in 5/16 have to be ordered separately, and you'll want them in brass too so you aren't mixing dissimilar metals at a bonding connection.