Metallics JSHC58212 5/8-11 x 2-1/2 in. Socket Head Hex Cap Screws - Alloy Steel Black - Each

They are 5/8-11 by 2-1/2 inches long, cut as a UN (unified national) thread at 11 threads per inch. That is the standard coarse pitch for 5/8 inch diameter, so it mates with 5/8-11 tapped holes and standard 5/8 coarse nuts.

In most cases yes, and that is the point of it. The 5/8-11 alloy steel socket head cap screw runs 170,000 psi minimum tensile and 153,000 psi minimum yield, higher than Grade 5 or Grade 8 hex head cap screws of the same size, and because it is wrenched internally with a hex key it needs less surface area around the head or a smaller counterbore. The tradeoff is access: you need clearance for a hex key straight down the axis rather than a wrench swing on the side.

No. The JSHC58212 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your contract carries a domestic sourcing clause, this part will not satisfy it and you need a domestically produced socket head cap screw instead.

No. The JSHC58212 is alloy steel with a black finish, which is a black oxide type appearance over bare alloy, not a plated or galvanized coating. Keep it to dry interior work such as panel, strut, equipment and machinery fastening. For wet or exterior locations pick a zinc plated or stainless fastener instead.

They ship in a jar, with a minimum of 25 each. So the smallest buy is a 25 piece jar rather than a single screw, which is usually how an electrical or mechanical shop stocks a common 5/8-11 length.

Yes. The screws run Rockwell C37 hardness with 153,000 psi minimum yield, well above the hardness of mild structural steel, so threads bite and hold in tapped steel. Ductility is specified too: 10 percent minimum elongation and 33 percent minimum reduction of area on machined specimens, so the fastener is not brittle at that hardness.

It is an internal hex (Allen) drive, not an external hex head, so it is driven with a hex key or hex bit rather than a wrench or socket. The socket in the head is 0.307 in. deep, which is enough engagement for a full-length key or a hex impact bit without camming out at this diameter.

Metallics lists them for the electrical, plumbing, heating and air conditioning trades, which is mounting panels, enclosures, pumps, compressors, hangers and equipment bases into tapped steel. The socket head suits tight spots where there is no room to swing a wrench but there is straight-line access from above.