Metallics JBBH78 Bolts 3/4-10 x 2-1/4 HXBT Sbr (Jar 50)

Silicon bronze. That is the reason to specify them: silicon bronze resists corrosion in wet and buried conditions and is the standard choice for grounding and bonding work where a plated steel bolt would corrode out. The material conforms to ASTM F468, the spec covering nonferrous bolts and screws for general use.

Yes. The JBBH78 is 3/4-10, meaning 10 threads per inch, which is standard UNC coarse for a 3/4 inch diameter, and the threads are cut to ANSI/ASME B1.1. Any 3/4-10 nut, tapped ground bar, or clamp body will take it. Mate it with a bronze or brass nut rather than plated steel if the joint is outdoors or in contact with soil, to avoid a dissimilar metal couple.

No. The JBBH78 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. If your contract carries a domestic-sourcing clause, this bolt will not satisfy it and you need a domestically produced silicon bronze fastener instead.

The JBBH78 ships as a jar of 50 bolts, and 50 each is the order minimum, so it is sold by the jar rather than the piece. Other sizes and quantities are available by request if 50 of this size is not what the job needs.

Metallics lists the field application as the electrical, plumbing, heating and air conditioning industries. In practice that means grounding and bonding connections, bronze pipe and valve flange work, and any damp or corrosive location where an electrician or plumber needs a nonferrous bolt. The 2-1/4 inch length suits clamping through a lug plus a bar or a pair of moderately thick flanged parts.

Both fall under the Metallics BBH and JBBH series of silicon bronze hex bolts. The JBBH prefix is the jar-packed presentation, which is how the JBBH78 ships, 50 bolts to a jar. The bolt itself is the same 3/4-10 x 2-1/4 silicon bronze hex bolt; the packaging is what the prefix tells you. Order by MPN JBBH78 to get the jar.

The finish is bronze, which is the natural color of the silicon bronze the bolt is made from rather than a coating, so there is nothing to chip or wear through. It visually matches bronze ground clamps, bronze lugs and brass hardware, and because it is nonferrous throughout it will not rust-streak an exposed installation.

A full jar runs 19.95 lbs, with the packed jar measuring 4.5 in by 4.5 in by 7.25 in. Worth knowing before you plan to carry several jars onto a roof or into a vault.