Metallics JG8HC19 Bolts 3/8-16 X 1/2 G8 Hxbt St-zn (Jar 100)

Yes. The Metallics JG8HC19 is a 3/8-16 bolt, meaning 16 threads per inch on a 3/8 inch nominal diameter, which is the standard UNC coarse pitch for that size. Measured shank diameter runs 0.3690 to 0.3750 inch, so it drops into any 3/8-16 tapped hole or nut. Use a Grade 8 nut if you want the joint to develop the bolt's full strength.

Grade 8 buys you tensile strength. These are medium carbon steel, heat treated, rated 150,000 psi minimum tensile and 130,000 psi minimum yield, with a hardness of Rockwell C33-39. Grade 5 cannot reach those numbers. If the joint is vibration loaded or carrying high clamp loads, which is why these are common in automotive and fleet work, Grade 8 is the right call. For general low-load mounting, a Grade 5 or an 18-8 stainless bolt is usually enough and will handle corrosion better.

No. The JG8HC19 Grade 8 hex bolt is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your contract carries a domestic sourcing clause, this part will not satisfy it and you need a domestically produced fastener instead.

Not much, and that is the point of this size. The JG8HC19 is 3/8-16 by 1/2 inch overall under the head, so it suits thin stacked material, bolting a bracket to a tapped boss, or any hole where a longer bolt would bottom out or protrude. If you are clamping two pieces of structural steel, you need a longer bolt in the same series.

The JG8HC19 is steel with a zinc finish, which handles indoor and sheltered conditions and incidental moisture. Zinc plating is a sacrificial coating, not a marine one, so for continuous wet exposure, washdown areas, or coastal sites you want stainless or hot dip galvanized instead. Note too that Grade 8 fasteners are more sensitive to hydrogen embrittlement than lower grades, so avoid stacking additional plating on them.

They ship in a jar of 100, and 100 count is the order minimum. That packaging suits a service truck or a shop bin rather than a one-off repair, so plan on a full jar per order.

Material conforms to AISI 1021 through 1045, a medium carbon steel range, then heat treated to reach Grade 8 properties. That is what gets the bolt to Rockwell C33-39 hardness. One practical consequence: do not weld these. Heat treated medium carbon fasteners lose their temper and you are left with a bolt that no longer meets Grade 8.

Yes. The G8HC and JG8HC series covers other sizes and quantities beyond the 3/8-16 x 1/2 inch jar of 100, available by request. Give the diameter, thread pitch, and length you need and the matching part in the series can be sourced.