Metallics JSPM16SS 10-24 x 1/2 in. Pan Head Slotted Machine Screws - 18-8 Stainless - Each

The Metallics JSPM16SS is a 10-24 UNC thread screw, which is the standard thread used on steel outlet boxes, device mounting ears and cover plates in North American electrical work. The thread is 24 threads per inch in coarse UNC form, so it mates with any tapped 10-24 hole.

Yes. The screws are 18-8 stainless, an austenitic stainless that resists rust in damp, washdown and coastal exposure, which is why it gets specified for exterior enclosures, pool rooms, food plants and marine work in place of zinc plated steel.

No. A machine screw has a straight machine thread and no cutting point, so it needs an existing tapped hole or a nut. On untapped sheet metal you want a self-tapping sheet metal screw or a #10-24 tapped clip or nut behind the panel. Standard tap for this thread is a 10-24 UNC.

They take a slotted driver, and the specified driver size is #2. Slot width runs 0.05 to 0.06 inch with a slot depth of 0.053 to 0.068 inch, so a standard medium flat blade seats properly. Note these are not Phillips or combo head, so if your crew drives everything with a #2 Phillips bit you will want a flat tip on the gun.

Head width measures 0.357 to 0.373 inch with a head height of 0.099 to 0.11 inch, built to ASME B18.6.3-2010. That low profile and broad bearing surface is what lets a pan head sit over a slightly oversized or slotted mounting hole without pulling through, while staying flat enough to clear a cover plate.

Pan head is the right call when the surface is flat and not countersunk: the head bears on top of the material and clamps a bracket, strap or plate down. Use a flat head only where the hole is actually chamfered or countersunk for it, otherwise the conical head will rock and never seat. These are pan head, built to ASME B18.6.3-2010 dimensions.

Tensile strength is listed at 80,000 psi minimum with hardness at Rockwell BBS-B9S. Metallics notes that tensile values for stainless screws are approximations, since there is no single performance standard for stainless machine screws. If you need a certified strength grade for a structural connection, a graded steel fastener is the correct choice; these are specified for corrosion resistance in general mounting work.

They come in a jar of 100, and 100 count is the order minimum. Jar packaging is practical for a shop bench or a service van drawer rather than loose bagged counts. Jar weight is listed at 0.55 lbs.

Metallics lists the JSPM16SS as both Buy American compliant and ARRA compliant, with country of origin recorded as multiple. That matters on federally funded, municipal and institutional work where fastener sourcing gets audited alongside the larger material submittals.