Metallics JHTB95 Bolts 5/16-18 x 5 Hx Tap Blt St-zn (Jar 50)

It's a 5/16-18 hex tap bolt, 5 inches long. The 18 threads per inch is the standard UNC coarse pitch for 5/16 diameter, so it mates with 5/16-18 nuts, channel nuts, and tapped holes. Threads run the full length on a tap bolt, which is what separates it from a hex cap screw with a plain shank.

Tensile strength is 60,000 psi minimum with a hardness of Rockwell B69 to B100. That is general-purpose low-carbon fastener strength, fine for mounting boxes, strut, brackets, and equipment supports. It is not a high-strength structural bolt, so if your drawing calls out a specific grade for a load-bearing or seismic connection, specify that grade instead.

Both ARRA and Buy American are flagged compliant on this bolt, which is what a government, school, or municipal procurement file usually needs documented. Country of origin is listed as multiple, so if your contract requires a single named origin on the submittal, confirm the origin on the lot you receive.

The hex head measures 0.484 to 0.500 inch across the flats, so a 1/2 inch wrench or socket is the right tool. Across corners it runs 0.552 to 0.577 inch, which matters if you're driving it inside a tight strut channel or a box where clearance is short.

The bolt is steel with a zinc finish, which handles general indoor and protected exterior service. For wet, washdown, coastal, or chemically aggressive locations, step up to the stainless version of the series (JSHTB) rather than zinc-plated steel.

They ship 50 to a jar, and 50 each is the order minimum. The jar pack is the reason this one works well on a service van or a stockroom shelf, and other sizes and quantities can be requested.

Threads are made to IFI-199 (2014), the industry inch thread spec, at 18 TPI. Any standard 5/16-18 nut, strut channel nut, or tapped 5/16-18 hole will take it without chasing threads.

A 5 inch length is for stacking through thick assemblies, through-bolting timber or layered backing, or sandwiching strut plus a standoff and bracket. Because a tap bolt is threaded the full 5 inches, you can set the nut anywhere along it rather than being locked to one grip range. If your grip is only an inch or two, a shorter bolt in the same HTB series saves you cutting off excess thread.