Metallics JPMP40BR Screw 10-24 x 1 PN PH MS BR (Jar 100)

Yes, that's its intended use. The 10-24 thread matches the tapped holes in standard steel electrical boxes, plaster rings and fixture straps, and the 1 inch length gives you reach when you're going through a ring or an extension. If you only need to hold a device flush to a flat box ear, a shorter 10-24 screw is tidier; the 1 inch length is for stacked or recessed conditions.

Thread pitch, and they do not interchange. A 10-24 has 24 threads per inch and is the thread found in most steel outlet boxes and device rings; 10-32 has 32 threads per inch and shows up in rack rails, some fixture canopies and tapped plates. Forcing one into the other strips the tapped hole, so match the pitch to the hole before you order.

Yes. The designation PN PH means pan head with a Phillips drive, so it seats flat against the surface with a low rounded crown and drives with a Phillips bit, typically a #2 for a #10 screw.

The BR in the 10-24 x 1 pan head Phillips machine screw call-out is brass. That matters where you need a non-ferrous, non-sparking fastener or want to match brass hardware and bonding points rather than use plated steel.

100 pieces per jar, and the jar is the pack type, so you order it as one container rather than loose counts. That's a sensible shelf quantity for a service van or an MRO crib where 10-24 machine screws get used across many boxes and plates.

It's a brass 10-24 x 1 pan head machine screw, non-ferrous and conductive, and 10-24 is the thread used in bonding holes on steel boxes. Be aware that listed equipment grounding screws are usually specified green and marked as such; if your inspection requires an identified green grounding screw, order one specifically rather than substituting this brass screw.