Metallics JBRHC42 Bolts 5/16-18 x 3/4 HXBT Br (Jar 100)

Solid brass. The JBRHC42 hex bolt lists brass as the material, and the head color is brass as well, so there is no plating over a steel core to wear through. That is why it gets used for grounding and bonding connections, where a brass bolt into a brass or copper lug keeps the dissimilar-metal problem out of the joint.

It is a 5/16-18 bolt, 18 threads per inch, which is the standard UNC coarse pitch for 5/16 diameter. Any standard 5/16-18 nut or tapped 5/16-18 hole will accept it. Measured thread outside diameter runs 0.3065 to 0.3125 in.

The hex head measures 0.489 to 0.500 in. across the flats, so a 1/2 in. wrench or socket is the one to grab. Head height is 13/64 in., with 0.14 in. of wrenching height, so keep that in mind if the bolt sits in a recess or counterbored pocket where a thin-wall socket is needed.

It ships as a jar of 100 bolts, and 100 count is the order minimum, so you are buying by the jar rather than by the piece. The filled jar weighs 1179 g. For service trucks and shop stock that works out well; one jar covers a lot of ground-bar and enclosure work before you reorder.

The record flags the JBRHC42 as both Buy American compliant and ARRA compliant, while the country of origin is listed as China. If your project specification requires domestic melt and manufacture rather than the compliance flag alone, have your specifying authority confirm which standard the job is written to before you commit the material.

The jar contains bolts only. No nuts, washers, or lugs are included, so order 5/16-18 nuts and any flat or lock washers you need as separate line items. For a grounding connection, match them in brass as well so you are not putting a zinc-plated steel nut against a brass bolt in a damp enclosure.

For grounding and bonding, brass is the choice. It is conductive, it resists corrosion in damp and outdoor enclosures, and it pairs with copper ground bars and bronze lugs without setting up the galvanic action you get between copper and plated steel. Use plated or stainless steel instead when the connection is purely structural and you need higher tensile strength, since brass is the softer material of the two. The JBRHC42 is solid brass through the head.

Yes. The JBRHC series is offered in other sizes and quantities by request, so if a 3/4 in. length is too short for your stack-up or a jar of 100 is more than the job needs, ask for the size and pack you want rather than buying around it.