Metallics RM100-5M Screws 1/4-20 x 3/4 RH CD MS St-Zn (5000 pcs)

The RM100-5M is a 1/4-20 x 3/4 inch round head machine screw, so it threads directly into any 1/4-20 tapped hole, channel nut, or spring nut. With 3/4 inch of length under the head you get enough engagement for a standard 1/4-20 strut nut or tapped flange while leaving the fastener short enough that it won't bottom out in a shallow box. Steel with zinc plating.

It's a machine screw, not a self-tapper. The 1/4-20 thread is a blunt-end machine thread that needs a mating tapped hole or a nut, so it will not cut its own threads in sheet steel. If the hole in your enclosure is unthreaded, you need a nut on the back side or a thread-cutting screw instead.

They're combination drive, so the head takes either a #2/#3 Phillips bit or a flat blade. That's handy on an electrical job where you're already carrying a 10-in-1 and don't want to swap bits between panel screws and strut hardware.

These are zinc plated steel, which is a dry-location and indoor-protected finish. It handles handling and storage corrosion, not standing water or weather. For exterior enclosures, damp or wet locations, or anything washed down, go to a stainless 1/4-20 machine screw rather than zinc plated carbon steel.

A round head sits fully on top of the surface with a domed crown and a flat bearing face, so it works for surface mounting straps, covers, and brackets where you don't need a flush finish. It will not sit flush in a countersunk hole, that calls for a flat head. Pan head is the lower-profile equivalent if clearance above the surface is tight.

It's a bulk pack of 5,000 pieces, which is a shop or truck-stock quantity rather than a job box. If you're standardizing on 1/4-20 x 3/4 round head combo machine screws across a facility or a multi-building electrical rough-in, one pack covers a lot of ground.