Metallics JG8HC763 Bolts 7/16-14 x 3 G8 HXBT St-zn (Jar 50 )

It is a 7/16-14 hex cap screw, 3 inches long. The 14 threads per inch is the UNC coarse pitch for 7/16 diameter, so any standard 7/16-14 coarse nut or tapped hole mates with it. Shank outside diameter runs 0.4305 to 0.4375 in.

Across-flats width on the hex head measures 0.612 to 0.625 in., which is a 5/8 in. wrench or socket. Head height is 19/64 in., so it sits low enough for most counterbored or tight-clearance work.

They ship 50 to a jar, and 50 each is the order minimum, so the jar is the buying unit rather than individual pieces. Total jar weight is 1724 g. Metallics does list other sizes and quantities as available by request.

The finish is zinc plate over medium carbon steel, which handles indoor and sheltered exterior service but is not a marine or chronically wet-location coating. For standing water, washdown, or coastal exposure, go to a stainless or hot-dip galvanized fastener instead. Note that a Grade 8 strength level has no stainless equivalent, so if you need both the strength and the corrosion resistance the substitution is not one-for-one.

Metallics flags this Grade 8 hex bolt as compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your project needs documentation tied to a single mill or country, request the certification with the order.

Material is AISI 1021 to 1045 medium carbon steel, heat treated to reach Grade 8 hardness of Rockwell C33-39. Do not weld it. Welding or torch-heating a heat-treated Grade 8 destroys the temper and drops the fastener well below its 150,000 psi rating. If the joint needs welding, use a weldable low-carbon stud instead.

Length is measured 3 inches from under the head to the tip on this hex cap screw, and head height adds another 19/64 in. above the surface. Stack your material thickness plus washers plus nut height against that 3 inches; you want at least a thread or two past the nut when it is tight.