Metallics JFM142W Screws 6-32 x 3 WTPaint MS St-zn (Jar 100)

The JFM142W is a 6-32 UNC machine screw, 32 threads per inch, cut to the ANSI/ASME B1.1 thread standard. 6-32 is the thread used on outlet box, switch box and plaster ring tapped holes, so it threads straight into them. Note it is a machine screw, not a self-tapping screw, so the hole or nut must already be tapped.

At 3 inches of length, the JFM142W reaches a device box that has been set deep behind thick finish material, stacked plaster rings, tile, or a furred-out wall. The screws packed with a receptacle or switch are typically under an inch and will not reach once the box is recessed. Same 6-32 thread, just enough shank to span the gap.

No. The JFM142W is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. For a project with domestic sourcing requirements you will need a domestically produced 6-32 machine screw instead.

Only the head is white. The head color is white paint over a zinc-finished steel screw, so the shank stays plain zinc-plated. That is what you want behind a white cover plate or white device, where the head shows and the shank does not.

Flat head, so it countersinks flush into a prepped hole. Head width runs 0.238 to 0.262 in. with a head height of 0.069 to 0.083 in. If your plate or ring has a flat counterbore rather than a cone, the head will stand slightly proud by that height.

Slotted drive, so it takes a standard flat blade screwdriver. Slot width is 0.039 to 0.048 in. and slot depth 0.024 to 0.038 in., so pick a blade that fills the slot. Slotted heads need less downward pressure than Phillips to drive, but they cam out sideways easily, so hand driving or a slow-speed driver with a well-fitted bit beats an impact gun on a 3 inch screw.

Rated at 550 lb minimum tensile strength, with a hardness of Rockwell B70 to B100, made from AISI 1006 to 1022 low carbon steel. That is adequate for mounting devices, plates, covers and light fixture hardware in tapped holes. It is a plain carbon steel fastener, not a graded structural bolt, so for a heavy suspended load use the fixture manufacturer's specified hanging hardware instead.

A machine screw is a straight shank fastener with uniform external threads that goes into a hole or nut already tapped to match. It cuts no thread of its own. Because the threads are fully formed and continuous rather than widely spaced, the resulting joint is stronger than a spaced-thread screw. If nothing in your assembly is tapped, you need a self-tapping or sheet metal screw, or you need to add a nut.

They come 100 to a jar, and 100 count is the order minimum. The jar is the practical part for a service van, you can pull a handful without the screws spilling loose in a bin.

Zinc plating over steel is a mild corrosion barrier intended for dry indoor use, which is where device boxes and cover plates normally live. In damp, wet or coastal exposure the plating will eventually rust through, especially where the white head paint gets chipped by a screwdriver. For wet locations specify a stainless 6-32 machine screw.

Head and slot dimensions follow ASME B18.6.3-1998, the standard for inch-series machine screws, and the threads follow ANSI/ASME B1.1. If the spec on your drawing calls out B18.6.3 slotted flat head 6-32, the JFM142W meets that designation.