Metallics JSHC58312 5/8-11 x 3-1/2 in. Socket Head Hex Cap Screws - Alloy Steel Black - Each

The JSHC58312 is an alloy steel socket head cap screw rated at 170,000 psi minimum tensile and 153,000 psi minimum yield, with a hardness of Rockwell C37. Metallics states the socket head design supplies greater tensile strength than equivalent sizes of Grade 5 or Grade 8 hex head cap screws, and because it's internally wrenched it needs less surface area or counterbore clearance than a hex head of the same diameter.

It's a 5/8-11 UN thread, 11 threads per inch, which is the standard coarse (UNC) pitch for 5/8 inch fasteners. It will thread into any 5/8-11 tapped hole or nut. Overall screw length is 3-1/2 inches.

No. It is not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. If your contract carries a domestic-content clause, this screw won't satisfy it and you'll need a domestically produced fastener instead.

Socket head with an internal hex (Allen) drive, so you wrench it with a hex key or hex bit socket rather than a wrench on the outside of the head. The hex socket is 0.307 in. deep, so use a key with enough straight length to seat fully and avoid rounding the socket at the torque these screws are capable of.

The JSHC58312 is alloy steel with a plain black finish. That's a bare or black-oxide type surface, not a plated or galvanized coating, so it offers little corrosion protection on its own. For exposed outdoor, rooftop, or damp locations, use a plated or stainless fastener, or coat the assembly. Indoors and in dry enclosures the black alloy screw is the usual choice where high strength matters.

They ship in a jar pack with an order minimum of 25 each, so the smallest purchase is 25 screws. Metallics notes other sizes and quantities are available by request if 5/8-11 x 3-1/2 in. isn't the size you need.

Metallics lists them for the electrical, plumbing, heating and air conditioning trades, which covers anchoring equipment feet, strut and channel connections, pump and motor bases, and machinery mounting where the joint needs high clamp load in a tight footprint. The internally wrenched head is what lets you use them in recessed or close-quarters locations a hex head wrench can't reach.