Metallics BBH37 Bolts 1/2-13 X 4 Hex Head CS Sbr (Jar 50)

The BBH37 is a 1/2-13 bolt, 13 threads per inch, cut to ANSI/ASME B1.1 Unified coarse thread. Any standard 1/2-13 UNC nut or tapped hole will take it. For a bronze installation, pair it with silicon bronze nuts so you are not mixing metals at the joint.

Solid silicon bronze, not a plated steel bolt. The bronze finish is the base metal itself, made to ASTM F468, which is the spec covering nonferrous bolts for general use. That matters where you need corrosion resistance in wet, marine, or chemically aggressive locations, and where a plated fastener would eventually rust through the coating.

That is the intended use. Metallics lists this bolt for the electrical, plumbing, heating and air conditioning trades, and silicon bronze is chosen in those trades because it conducts, resists corrosion, and will not set up galvanic trouble against bronze or copper hardware. If you are bolting to galvanized steel or aluminum in a dry interior run, a plated steel or stainless fastener is the more common and cheaper pick.

No on both counts. The BBH37 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. If your project has a domestic sourcing clause, this bolt will not satisfy it and you need a domestically produced silicon bronze fastener instead.

Shank length on the BBH37 is 4 inches measured under the head, so your total grip is 4 inches minus the nut and washers. Head height runs 0.302 to 0.323 inches and sits on top of the material, it is not part of the grip.

They ship 50 to the pack, and 50 each is the order minimum, so a jar is the smallest quantity. Other sizes and quantities in the BBH and JBBH series can be had by request.

The packed jar of BBH37 bolts weighs 12.7 lbs and measures 7.25 by 6.75 by 3.25 inches. Worth knowing if you are ordering several jars to a jobsite box or carrying them up a ladder in a bag.