Metallics JCB1 Bolts 1/4-20 X 3/4 Carriage Blt St-zn (Jar 100)

It is steel with a zinc finish, not stainless. Zinc plating handles dry interior and protected exterior work, like hanging conduit supports, strut, or equipment brackets. For continuous wet exposure, coastal air, or chemical contact, go with a 304/18-8 or 316 stainless carriage bolt in the same 1/4-20 x 3/4 size instead.

No. The JCB1 carriage bolt is not Buy American compliant and is not ARRA compliant, with multiple countries of origin. If your contract carries a domestic sourcing clause, you need a documented domestic-origin fastener instead.

The head is a mushroom (round) type measuring 0.563 to 0.594 inch across with a head height of 0.125 to 0.145 inch. Underneath it is the square neck that gives a carriage bolt its grip, so it seats and resists turning when you tighten the nut from the back side. In sheet metal or strut, use a washer behind the nut, since the low mushroom profile bears on a small area.

Yes. The JCB1 is manufactured to ASME B18.5-1990, the standard that governs round head square neck bolt dimensions, so head diameter, head height, and square neck size fall within that standard's limits. That is the figure to reference if a spec sheet asks for a dimensional standard on carriage bolts.

They ship in a jar of 100 pieces, and the jar is the minimum order unit, so 100 bolts is the smallest quantity. Jar weight is 753 g. Handy for a van or shop bin where loose fasteners get lost. Other sizes and quantities are available by request.

Metallics sells the JCB1 into the electrical, plumbing, heating, and air conditioning trades. Typical use is fastening hangers, strut, backing plates, panel and equipment brackets, and anywhere you want a smooth low-profile head on the exposed side with the nut tightened from behind.