Metallics JFM109 10-24 x 1-1/4 in. Flat Head Slotted Machine Screws - Steel Zinc - Each

Yes. The JFM109 is a 10-24 UNC thread, 24 threads per inch, cut to ANSI/ASME B1.1. That is the same 10-24 thread used on outlet box, switch box and mud ring tapped holes, so it threads straight in. Length is 1-1/4 inch, which is longer than a stock box screw, so it is the one to reach for when you are mounting a device through a thick plaster ring, extension or spacer stack.

That is what the flat head is for. Head width measures 0.333 to 0.362 inch and head height 0.098 to 0.116 inch, built to ASME B18.6.3-1998, so it seats in a standard 82 degree countersink for a #10 flat head and finishes flush with the surface. If you need the head to sit proud on a flat, un-countersunk surface, a pan or round head is the better choice.

No. The JFM109 is flagged as not Buy American compliant and not ARRA compliant, with country of origin listed as multiple. On a federally funded project with domestic sourcing requirements, you need a domestically produced fastener instead.

They ship 100 to a jar, and 100 is the order minimum, so the jar is the buying unit rather than loose pieces. Jar weight is 0.99 lbs. For a crew stocking a van or a shop restocking a bin, one jar covers a typical device-mounting run.

Zinc plated carbon steel is a dry, indoor-duty finish. The JFM109 is steel with a zinc finish, which handles normal interior electrical, plumbing and HVAC work fine, but it will corrode in wet, exterior or washdown locations. For those, specify a stainless machine screw in the same 10-24 x 1-1/4 size instead.

Rated at 1050 lb minimum tensile, with hardness in the Rockwell B70 to B100 range and steel to AISI 1006-1022. That is standard low-carbon commercial machine screw material, fine for mounting devices, covers, plates, brackets and straps. It is not a structural or high-strength grade, so anything carrying real load wants a graded bolt instead.