Metallics JG8HC582 Bolts 5/8-11 X 2 G8 Hxbt St-zn (Jar 25)

It's a 5/8-11 bolt, 2 inches long, so 11 threads per inch, which is the standard coarse (UNC) pitch for 5/8 inch. Any 5/8-11 coarse nut or tapped hole will thread onto it. Shank outside diameter runs 0.6170 to 0.6250 inch.

This is a Grade 8 cap screw with 150,000 psi minimum tensile and 130,000 psi minimum yield, hardness Rockwell C33-39. Grade 5 of the same diameter runs well below that, which is why Grade 8 gets specified for automotive, fleet, and heavy equipment work where the joint is carrying real load. Material is medium carbon steel per AISI 1021-1045, heat treated.

Metallics lists the JG8HC582 as both Buy American compliant and ARRA compliant. Country of origin is shown as multiple, so if your contract requires a single named origin, specify that at the time of order.

The finish here is zinc over steel, which handles normal indoor and sheltered outdoor exposure. It is not stainless. For constant moisture, salt spray, or direct weather on a long-life installation, zinc plating will eventually surface rust, so a hot dip galvanized or stainless fastener is the better call there (note that stainless does not come in Grade 8 strength).

They ship 25 to a jar, and 25 each is the order minimum, so the jar is the smallest unit. Total packed weight is 2513 g.

At 2 inches of length under the head, a Grade 8 bolt this size is partially threaded, so figure your total clamp stack plus enough thread to fully engage the nut (roughly one diameter, about 5/8 inch, of thread in the nut). If your grip is much past an inch, step up to a longer length. Metallics offers other lengths and quantities in the G8HC and JG8HC series by request.

Same Grade 8 zinc plated hex bolt, different pack. The JG prefix, as on JG8HC582, is the jar pack of 25. Both numbers sit in the same G8HC and JG8HC series, so the bolt spec does not change with the pack.