Metallics JFMB86 Screw 8-32 x 1 FH SL MS BR (Jar 100)

Yes. 8-32 is the thread used on receptacle and switch yokes, box screw holes, and plaster rings, so this 1 inch screw threads straight into them. The 1 inch length gives extra reach when a device sits proud of a deep-set or mud-ring box; for a flush device a shorter 8-32 is usually enough.

Brass. The JFMB86 is a brass machine screw, which is why electricians reach for it where a plated steel screw would corrode or where a non-ferrous fastener is wanted, such as damp locations and brass cover plates.

100 pieces per jar. It ships as a jar pack, which is the handy count for a van or shop bin rather than a bulk box, so one jar covers a run of device or plate installs without reordering mid job.

Use the flat head JFMB86 where the screw has to sit flush in a countersunk hole, such as a countersunk cover plate or a flush-mounted bracket. If the hole is not countersunk, a round or pan head is the better choice because it bears on the surface instead of trying to seat in a bevel. The slotted drive on this one takes a standard flat-blade electrician's screwdriver, no bit change needed.

It is a machine screw. The 8-32 thread is a straight machine thread meant to go into a tapped hole or a nut, not to cut its own thread in sheet metal. If you need to fasten into an untapped hole, you want a sheet metal or self-drilling screw instead, or you need to tap the hole 8-32 first.

Brass is conductive, so these are commonly used as bonding and terminal screws where a non-ferrous fastener is wanted. Note that a listed equipment grounding screw is normally identified green; the JFMB86 is a plain brass screw, so where your inspector requires a green-colored grounding screw, order that specific part instead.