Metallics JFM40 8-32 x 5/8 in. Flat Head Slotted Machine Screws - Steel Zinc - Each

8-32 is the standard thread for electrical device and cover plate screws, and that is what the Metallics JFM40 is: 8-32 UNC thread, 32 threads per inch, 5/8 in. long, flat head with a slotted drive. The 5/8 in. length gives you more engagement than the short screws that ship with a device, which is what you want when you are pulling a plate up over a deep box or shimming out from a recessed yoke. The flat head sits flush in a countersunk plate hole rather than standing proud.

These are AISI 1006-1022 carbon steel with a zinc finish. Zinc plating is a mild corrosion coating meant for dry interior service, not weather exposure. For a wet location, an exterior panel, a rooftop disconnect, or anywhere washdown or salt air is in play, step up to a stainless 8-32 machine screw of the same length instead. Indoors in a panel, box, or enclosure, the zinc plated steel is the normal choice.

Yes. The thread is cut to ANSI/ASME B1.1, 8-32 UNC, so it mates with any standard 8-32 tapped hole or 8-32 nut, which is what device yokes, box ears, and most sheet metal enclosure flanges are tapped for. Confirm you have at least the 5/8 in. of clearance or thread depth behind the hole so the screw does not bottom out before the head seats.

The JFM40 is flagged ARRA compliant and Buy American compliant in the manufacturer data, with China listed as the country of origin. Institutional and government buyers working to a domestic-preference clause should take those compliance flags to their specifying authority, since the applicable clause varies by funding source and project type.

Pick the flat head, like the JFM40, when the part you are fastening has a countersunk or chamfered hole and the fastener has to finish flush: cover plates, trim rings, anything that gets touched or that another panel sits against. A round or pan head belongs on a flat, un-countersunk hole, where the head bears on the surface and you want the extra bearing area. Putting a flat head on a straight-drilled hole leaves it loose and standing proud.

The JFM40 comes in a jar of 100, and 100 count is the order minimum. That is the shop-stock format: one jar on the truck or the parts shelf covers a lot of plate and cover work. Jar weight is 0.2 lbs.

Slotted drive, which is the traditional electrical fastener drive and the only drive on the JFM40. It is fine by hand or with a low-speed driver and a properly sized flat blade, but a slot cams out easier than a Phillips or square drive under high torque or an off-axis bit. For high-volume driving on a device plate job, keep the clutch low and the blade fully seated in the 0.045 to 0.054 in. slot.