Metallics JG8HC214 Bolts 3/8-16 X 1-1/4 G8 Hxbt St-zn (Jar 100)

It is a fine thread bolt. The JG8HC214 runs 16 threads per inch on a 3/8 diameter shank, which is UNF fine thread rather than the more common 3/8-16 coarse callout you see on standard hardware. Measured shank diameter is 0.3690 to 0.3750 inch. If your nuts or tapped holes are 3/8-16, these will thread in; if they are a different pitch, they will not start.

Grade 8 is the step up. The JG8HC214 is rated at 150,000 psi minimum tensile and 130,000 psi minimum yield, with a hardness of Rockwell C33-39, made from medium carbon steel heat treated to those numbers. Grade 5 tops out well below that, which is why Grade 8 gets specified on automotive and fleet work and anywhere the joint load exceeds what a Grade 5 can carry.

No. The JG8HC214 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. On a federally funded job carrying domestic sourcing requirements, you need a domestically produced fastener instead.

Head width across the flats measures 0.551 to 0.562 inch, which is a 9/16 inch socket or wrench. That is the standard hex size for a 3/8 bolt, so a normal 9/16 impact socket drives these.

The JG8HC214 is steel with a zinc finish, which handles indoor and sheltered conditions and incidental moisture. Zinc plating is a sacrificial coating, not stainless, so in constant wet, washdown, coastal or chemically aggressive service it will eventually corrode. For buried, submerged or exterior-exposed structural work, specify stainless or hot dip galvanized instead.

These ship as a jar of 100 pieces, and the jar is the minimum order unit, so 100 is the smallest quantity. Jar packaging keeps the count together in a van or on a shelf rather than loose in a bin. Metallics lists other sizes and quantities in the G8HC and JG8HC series by request.

Yes, Metallics lists this bolt for the electrical, plumbing, heating and air conditioning trades, and it is a plain hex cap screw so it works in strut nuts, beam clamps, hanger hardware and equipment mounting that takes a 3/8-16 fastener. The Grade 8 rating is more than most hanger loads require, so it is usually chosen where a single anchor point carries real load or where the spec calls out Grade 8 specifically.

Medium carbon steel in the AISI 1021 to 1045 range, heat treated to reach Grade 8 properties, then zinc plated. That material and heat treat is what puts the hardness at Rockwell C33-39. Note that hardened fasteners at this level should not be welded or re-heated, since that destroys the heat treat.