Metallics JG8HC4 Bolts 1/4-20 X 2 G8 Hxbt St-zn (Jar 100)

The JG8HC4 is a 1/4-20 hex bolt, 2 inches long, with 20 threads per inch (coarse UNC) and a shank outside diameter of 0.2450 to 0.2500 inch. Any 1/4-20 UNC nut or tapped 1/4-20 hole will take it. Match the nut grade to the bolt: a Grade 8 bolt paired with a low-grade nut will strip the nut before the bolt reaches its rated load.

Grade 8 buys you tensile strength, not corrosion resistance. The JG8HC4 is heat-treated medium carbon steel rated 150,000 psi minimum tensile and 130,000 psi minimum yield, at Rockwell C33-39 hardness, which is above what a Grade 5 can do. For routine strut and hanger work a Grade 5 is normally sufficient; reach for Grade 8 where the connection sees high clamp load, vibration, or shear, such as equipment anchoring, seismic bracing hardware, or fleet and automotive repair. Note that higher hardness also means less ductility, so Grade 8 is not the right choice where you want a fastener to stretch rather than snap.

Fastener length on the JG8HC4 is 2 inches, measured under the head on a standard hex bolt. Add up your material stack plus washers plus the nut height to confirm you have enough thread engagement left; at this length a 1/4-20 bolt is partially threaded, so if your grip is short the unthreaded shank can sit in the nut and prevent full tightening. For thin stacks, a shorter length in the same series is the better pick.

No. The JG8HC4 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 bolt will not satisfy it and you need a domestically produced Grade 8 hex bolt instead.

Head width across flats measures 0.428 to 0.438 inch on the JG8HC4, so a 7/16 inch wrench or socket is the fit. It is a standard hex head, drivable with an open end, box end, or socket in tight electrical enclosures.

The JG8HC4 is steel with a zinc finish. Zinc plating handles indoor and sheltered conditions and incidental moisture, but it is a sacrificial coating, not stainless. For continuous wet exposure, coastal air, or chemical environments, specify hot-dip galvanized or stainless instead. Also avoid bolting zinc-plated steel directly to aluminum or copper in a wet location, since the dissimilar metals will drive galvanic corrosion.

The JG8HC4 ships as a jar of 100 bolts, and 100 in the jar unit is the order minimum, so it is sold by the full jar rather than by the piece. Metallics lists other sizes and quantities in the G8HC and JG8HC line by request.

Medium carbon steel in the AISI 1021 to 1045 range, quenched and tempered to Grade 8 properties. That heat treatment is what gets it to Rockwell C33-39 and 150,000 psi minimum tensile. One practical consequence: do not weld or re-heat these bolts, since heating undoes the temper and drops the strength you specified them for.