Metallics JCB4 Bolts 1/4-20 X 2 Carriage Blt St-zn (Jar 100)

It's 1/4-20, meaning 20 threads per inch, right hand thread, so any standard 1/4-20 hex nut, nylon insert lock nut, or 1/4-20 threaded insert mates with it. Nuts and washers are not part of the jar, so order them separately if you don't have them on the truck.

Zinc plated steel is a dry-to-mildly-damp duty finish. It's fine inside mechanical rooms, ceilings, and covered areas, but direct weather exposure, coastal air, treated lumber, or wash-down areas will eat the plating and then the steel. For those conditions go to a stainless carriage bolt (18-8 or 316) in the same 1/4-20 x 2 size instead.

No. The JCB4 is not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. If your project has domestic sourcing requirements, this bolt will not satisfy them and you'll need a domestically manufactured fastener.

They ship 100 pieces to a jar, and the jar is the order minimum, so the smallest quantity is 100. Total jar weight is 1293 g. Metallics notes other sizes and quantities are available by request.

The JCB4 is rated 60,000 psi minimum tensile and 36,000 psi minimum yield, with a hardness of Rockwell B70 to B100. That is the low-carbon commercial grade range, which is right for hanging strut, mounting brackets, panelboard backing, and general trade bracketry. It is not a high-strength bolt, so if a drawing calls out a graded fastener for a structural or seismic connection, this isn't the part.

The head is a mushroom (round, domed) profile with a square shoulder beneath it. That means a low, smooth head on the finished side with nothing to snag and no socket to tamper with, and the square shoulder locks the bolt so you can tighten from one side with a single wrench. A hex bolt needs a wrench on both ends; a lag screw threads into the material and can't be re-tensioned the same way. Use a carriage bolt where you can reach both faces and want a clean exposed head.

Head width runs 0.563 to 0.594 inch (about 9/16) and head height is 0.125 to 0.145 inch. So the head sits just over an eighth of an inch proud of the surface and spans a little over half an inch, which matters if you are bolting through a slotted strut channel or need the head to clear a panel cover or trim piece.

Dimensions conform to ASME B18.5-1990, the standard covering round head bolts including carriage bolts. That is the spec to reference if a submittal or inspector asks what the head geometry and shoulder are built to.

Metallics lists it for the electrical, plumbing, heating, and air conditioning industries. In practice that's strut and channel assemblies, hanger and bracket mounting, equipment stands, backboards and plywood backing for panels, and general MRO fastening where you want a low smooth head on the visible side. Keeping a jar of 100 on the shelf covers most 1/4-20 bracket work on a building.