Metallics JCB8 Bolts 1/2-13 X 6 Carriage Blt St-zn (Jar 25)

The JCB8 is a 1/2-13 carriage bolt, so it takes a standard 1/2-13 UNC nut. Thread pitch is 13 threads per inch, and the shank measures 0.492 to 0.515 inches across. Nuts and washers are not part of the jar, so order them separately.

Overall length is 6 inches measured from under the head, so the usable grip is 6 inches minus whatever the nut and washer take up. For through-bolting a double 2x timber beam or a bracket onto a 4x post it has length to spare; for thinner assemblies you will have excess thread sticking out and may want a shorter bolt.

Zinc plated steel handles covered and dry locations and brief weather exposure, but plating is sacrificial and will corrode in sustained wet service or against modern pressure treated lumber and in coastal air. For a deck ledger, gate post, or anything exposed, specify hot dip galvanized or stainless instead.

Metallics lists the JCB8 as both ARRA compliant and Buy American compliant. Country of origin is recorded as multiple, so if your contract requires documented origin on a specific lot, request the certification for the lot being shipped.

Mushroom head, 1.032 to 1.094 inches across the top and 0.250 to 0.270 inches high. That wide low dome spreads load on wood without a washer under the head and sits nearly flush, which matters on a handrail, gate, or any surface someone will brush against.

They ship as a jar of 25 pieces, and 25 count is the order minimum, so a single jar is the smallest purchase. Other sizes and quantities can be arranged on request.

Dimensions follow ASME B18.5-1990, the round head bolt standard. That means head diameter, head height, square neck, and thread dimensions are to spec, so the JCB8 interchanges with any other 1/2-13 x 6 carriage bolt built to the same standard.

Carriage bolts like the JCB8 are made for wood: the square neck under the mushroom head embeds in the material so one wrench on the nut does the job, and the smooth dome leaves no sharp head exposed. Through steel channel, strut, or sheet metal there is nothing for the neck to bite into, so the bolt spins and you end up holding the head anyway. Use a hex head bolt or a strut-specific fastener for metal-to-metal work.