Metallics JFM144 6-32 x 4 in. Flat Head Slotted Machine Screws - Steel Zinc - Each

Yes. The Metallics JFM144 is a 6-32 UNC screw with 32 threads per inch, cut to ANSI/ASME B1.1, which is the thread used for receptacle, switch and device mounting in standard outlet boxes. At 4 inches long it is meant for deep-set work, such as reaching a device through thick plaster, stacked mud rings or an extension ring, not for a flush box where a 1-inch screw is enough.

No. The JFM144 is listed as not Buy American compliant and not ARRA compliant, with country of origin reported as multiple. If your contract carries a domestic sourcing clause, this screw will not satisfy it and you need a documented domestic fastener instead.

It is a flat head, so it is made to seat in an 82-degree countersink and finish flush with the surface. The head measures 0.238 to 0.262 in. across and 0.069 to 0.083 in. high, dimensioned to ASME B18.6.3-1998, so it drops into any standard #6 flat head countersink. If you need the head to sit on top of the material instead, use a round or pan head rather than this one.

They ship in a jar, with a minimum order of 100 pieces. So the buying unit is a 100-count jar rather than a single screw, which is the usual way an electrical contractor or MRO stockroom carries this size.

The JFM144 carries a 550 lb minimum tensile strength, with a hardness of Rockwell B70 to B100, made from AISI 1006 to 1022 low carbon steel. That is a plain unhardened commercial screw, fine for mounting devices, plates, covers and sheet metal assemblies, but it is not a graded structural fastener and should not be substituted for one on a load-bearing connection.

Zinc plated carbon steel gives moderate indoor corrosion protection only. For wet, washdown, coastal or chemically exposed work, move to a stainless 6-32 flat head slotted screw in the same length instead. Note too that hardness and tensile figures quoted for stainless machine screws are guides only, since there is no national standard for those performance requirements on stainless machine screws.

It is stocked for the electrical, plumbing, heating and air conditioning trades. The long length covers deep device mounting, standoff and through-bolting situations where a standard device screw cannot reach, and the yellow zinc version of these screws is common in electronics assembly work.

1.28 lbs is the stated product weight for the jar. Light enough to add to any order without changing freight, which matters if you are stocking several thread sizes of the FM and FMP series machine screws at once.