Metallics JFM117 8-32 x ª4 in. Flat Head Slotted Machine Screws - Steel Zinc - Each

It's an 8-32 UNC thread, 32 threads per inch, cut to ANSI/ASME B1.1. That means it threads straight into any standard 8-32 tapped hole or 8-32 nut, which is the common size for device yokes, switch and receptacle mounting, and panel hardware.

Yes, that's what the flat head is for. The JFM117 head measures 0.285 to 0.312 in. across with a head height of 0.084 to 0.1 in., built to ASME B18.6.3-1998, so it seats flush in a standard 82-degree countersink for a #8 flat head screw. If your plate or box isn't countersunk, you want a round or pan head instead so the head bears on the surface.

No. The JFM117 is marked not Buy American compliant and not ARRA compliant, with multiple countries of origin. If your contract carries a Buy American or ARRA domestic-sourcing clause, these will not pass submittal and you need a domestically produced fastener instead.

These are steel with a zinc finish, which is a plating meant for dry indoor and protected use, the electrical, plumbing and HVAC work the series is built for. Zinc plating gives light corrosion resistance only. For wet locations, exterior boxes, or coastal and washdown environments, go with a stainless steel machine screw in the same 8-32 size rather than zinc plated steel.

They ship in a jar of 100, and 100 is the order minimum, so the smallest purchase is one full jar. That's the practical buy for a service van or a shop drawer where 8-32 flat heads get consumed constantly. Metallics notes other sizes and quantities can be arranged by request.

A machine screw such as the JFM117 has a straight, uniform 8-32 UNC thread with a blunt end. It needs a pre-tapped hole or a nut, it will not form its own thread. Self-tapping and sheet metal screws have a sharper, coarser thread that cuts into unthreaded material. If you're fastening into an existing threaded boss, device strap, or a nut, a machine screw is correct. If you're going into bare sheet or an unthreaded hole, pick a tapping screw.

Two standards apply to the FM and FMP series flat head slotted screws: dimensions to ASME B18.6.3-1998 and threads to ANSI/ASME B1.1, with material per AISI 1006 to 1022. That's enough to satisfy a spec line calling for standard slotted flat head machine screws. Note that the hardness and tensile figures Metallics publishes for stainless machine screws are guides only, since there is no national standard for those stainless performance values.