Metallics JG8HC50 Bolts 1/2-13 x 2-3/4 G8 HXBT St-zn (Jar 25)

It's a 1/2-13 x 2-3/4 inch hex cap screw: 1/2 inch nominal diameter, 13 threads per inch (UNC coarse), 2-3/4 inches of length under the head. Match it with a 1/2-13 nut or a tapped 1/2-13 hole; it will not thread into a 1/2-20 fine-thread hole.

Yes, and that is the point of the JG8HC50. It's a Grade 8 medium carbon steel cap screw, heat treated, with 150,000 psi minimum tensile and 130,000 psi minimum yield, hardness Rockwell C33-39. That's a step up from Grade 5 in a bolt of the same 1/2-13 thread, so it drops into the same hole and nut while carrying more load. Note that Grade 8 is harder and less ductile, so torque it to Grade 8 values, not the Grade 5 figures.

No. The JG8HC50 hex cap screws are not Buy American compliant and are not ARRA compliant, with country of origin listed as multiple. If your contract carries a domestic sourcing clause, you need a documented domestic fastener instead.

They ship in a jar of 25, and 25 each is the order minimum, so a single piece or a count of ten isn't an option. Metallics also offers other sizes and quantities of the G8HC/JG8HC hex cap screws by request if 25 of this length isn't what the job needs.

The finish is zinc plating over steel, which handles indoor, mechanical room, and sheltered conditions well. For direct weather exposure, salt spray, or coastal work it is a mild protection only, and plated Grade 8 fasteners should not be used where hydrogen embrittlement or constant wetting is a concern. For sustained outdoor or corrosive duty, specify stainless or hot dip galvanized hardware instead.

Grade 8 belongs where the joint sees high clamp load or shock: automotive and fleet work, equipment mounting, machinery and structural steel connections where Grade 5 doesn't carry enough tensile. For light duty strut, enclosure, and general electrical mounting, a Grade 2 or Grade 5 zinc bolt is usually the sensible call, since a 150,000 psi fastener adds nothing to a joint that never approaches that load.

Medium carbon steel in the AISI 1021 to 1045 range, heat treated to reach Grade 8 properties and finishing at Rockwell C33-39. That hardness is why they hold 150,000 psi minimum tensile, and also why they should not be field welded, bent, or re-heated.

Standard hex head cap screws in 1/2-13, so a 3/4 inch socket or wrench across the flats is what fits a typical 1/2 inch hex bolt head. There's no washer, nut, or driver bit in the jar, just the 25 bolts, so order nuts and washers separately if the connection needs them.