Metallics JFM97 10-24 x 2-1/2 in. Flat Head Slotted Machine Screws - Steel Zinc - Each

The Metallics JFM97 is a 10-24 UNC screw with 24 threads per inch, cut to ANSI/ASME B1.1. That is the same 10-24 thread used on standard outlet box and device mounting holes, so it threads straight into box ears, mud rings and plaster rings. At 2-1/2 inches long it is meant for deep-set boxes or thick build-ups where a standard 1-inch box screw runs out of reach.

Flat head, so it needs a countersunk hole to finish flush. The head measures 0.333 to 0.362 in. across and 0.098 to 0.116 in. high, built to ASME B18.6.3-1998, which is the standard 82 degree flat head profile. If your hole is drilled straight through with no countersink, the head will stand proud and you want a round or pan head instead.

1050 lb minimum tensile on the JFM97, with the steel running Rockwell B70-B100 hardness and made from AISI 1006-1022 low carbon steel. That is ordinary commercial machine screw strength, fine for mounting devices, covers, straps and light brackets. It is not a structural or high strength fastener, so do not substitute it where a graded bolt is called out on the drawing.

Zinc plated carbon steel, which is a dry-location and protected-location finish. Plated steel will corrode in wet, washdown or coastal exposure. For exterior boxes, roof penetrations or anything that stays damp, use a stainless machine screw in the same 10-24 x 2-1/2 size instead.

They ship in a jar, 100 count, and 100 is the order minimum. So it is a jar at a time rather than a loose handful, which suits a service van or shop stock rather than a one-screw repair. Jar weight is 1.89 lbs.

Slotted drive, with a slot 0.05 to 0.06 in. wide and 0.034 to 0.053 in. deep. A slot that shallow and narrow cams out easily under a power driver, so it is a hand screwdriver fastener in practice. If your crew drives everything with impacts, specify a Phillips or combination head machine screw instead.

The JFM97 is flagged compliant for both ARRA and Buy American in the manufacturer data, with country of origin China. If your contract runs under a stricter domestic sourcing clause than the ARRA flag covers, verify against the specific clause on your project before you submit.

A machine screw has a uniform machine thread (10-24 UNC here) and no point that cuts its own hole. It goes into an already-threaded hole or through a hole into a nut. Sheet metal and self-tapping screws form their own thread in unthreaded material. So the JFM97 is the right choice for box ears, device straps, and tapped brackets, and the wrong choice for driving into bare sheet or a drilled pilot with no threads.

The FM and FMP series from Metallics covers other lengths and pack quantities beyond the 2-1/2 in. JFM97, available by request. If you are standardizing a building on one 10-24 screw, order the series by the length you need rather than cutting these down.