Metallics JRM127 10-24 x 3 in. Round Head Combo Machine Screws - Steel Zinc - Each

The Metallics JRM127 is a 10-24 thread with 24 threads per inch, which is the machine screw thread used throughout electrical boxes, device rings and fixture straps. It mates with any 10-24 tapped hole or 10-24 nut. At 3 inches long it is meant for deep builds, not flush device mounting.

Either one. The JRM127 head carries both a slot and a Phillips recess in the same head, so you can drive it with a flat blade or a #2 Phillips. The slot runs 0.05 to 0.06 inch wide and 0.065 to 0.087 inch deep; the Phillips recess is 0.182 to 0.195 inch across and 0.093 to 0.119 inch deep. On a service call that means one screw works with whatever driver is already in your hand.

No. The JRM127 is not Buy American compliant and not ARRA compliant, and country of origin is listed as multiple. On a federally funded project with domestic sourcing requirements you will need a domestically produced fastener instead.

Three inches of 10-24 gives you room to reach through thick plaster, stacked extension rings, or a deep mud ring and still get enough thread engagement in the box ears. If your buildout is under an inch, a shorter 10-24 is the better choice; this one is for the deep ones.

The JRM127 is zinc plated steel, made from AISI 1006 to 1022 low carbon steel. Zinc plating handles dry interior and protected locations well. For wet exterior, corrosive, or coastal work, specify a stainless machine screw of the same 10-24 x 3 size rather than zinc.

They ship in a jar of 100, and 100 is the order minimum. For a stocked service van or an MRO shelf that is one jar per bin location; the filled jar weighs 1.97 lbs.

Tensile strength is 60,000 psi minimum with a case hardness of Rockwell B70 to B100. That is standard low carbon steel machine screw strength, fine for mounting devices, straps, plates and light fixture hardware. It is not a structural or high strength bolt substitute.

Metallics built the JRM line for the electrical, plumbing, and heating and air conditioning trades. The combo head is the reason: one screw covers both slotted and Phillips drivers, which is why it ends up in electrician and mechanical service stock rather than general hardware bins.