Metallics JSRM154 10-24 x 6 in. Round Head Slotted Machine Screws - 18-8 Stainless - Each

The Metallics JSRM154 is a 10-24 thread, 24 threads per inch, which is the standard machine screw thread used on steel device boxes, fixture straps and most electrical mounting hardware. If the hole in your box or strap takes a standard 10-24 ground screw or fixture screw, this threads straight in. At 6 inches long it is meant for deep mounting situations, not flush box work.

18-8 stainless is the standard austenitic grade used for general corrosion resistance, so these hold up in damp and outdoor locations where a plated steel screw would rust. It is not the grade for salt spray or coastal marine exposure, where 316 stainless is the usual step up. Note the tradeoff: stainless gives you corrosion resistance, not high strength. The JSRM154 is rated 80,000 psi tensile minimum with hardness of Rockwell B85 to B95, well below a hardened alloy steel screw.

Head height runs 0.123 to 0.137 in. and head width 0.334 to 0.359 in. on this 10-24 round head screw. So figure roughly an eighth of an inch of domed head sitting proud of the surface and a little over a third of an inch of bearing diameter. That matters two ways: the round head will not sit flush in a countersunk hole (you want a flat head for that), and the 0.334 in. minimum head diameter has to be larger than the hole you are pulling against.

These come in a jar, with a minimum order of 50 count. The jar of 50 weighs 3.33 lbs. That is a stocking quantity for a van or a shop drawer rather than a single-screw pickup, which suits MRO and electrical contractor buying.

The record carries both an ARRA compliant and a Buy American compliant flag on this screw, with country of origin listed as China. On federally funded work those two things need reconciling against your project's specific clause before you submit it, because the governing requirement varies by contract.

Treat the 80,000 psi minimum as an approximation, not a certified performance grade. There is no single standard setting performance requirements for stainless machine screws, so the number is given as a guide. The screws are built to SAE material standards with hardness in the Rockwell B85 to B95 range. If your submittal needs a certified proof load, a graded carbon steel fastener is the path, not stainless.