Metallics JG5HSF383 Bolt 3/8-16 x 3 Ind Hx Hd Serr Fla (Jar 50)

No. The JG5HSF383 has a serrated flange head, so the flange spreads the load like an integrated washer and the serrations bite into the mating surface to resist loosening from vibration. That's one less loose part on a strut or panel job. Keep in mind the serrations will mar a finished or painted surface, so if appearance matters use a plain hex bolt with a finish washer instead.

Fifty bolts, supplied in a jar. The jar pack is handy for a service van or a shop bin since you can scoop out what you need and reseal it, rather than dealing with a split carton. If you're consuming 3/8-16 x 3 bolts in volume on one job, order multiple jars.

Yes, that's the usual application for this Metallics fastener, which is carried as an electrical fastener. The 3/8-16 thread matches the common hardware used with strut channel nuts and equipment mounting brackets, and the 3 inch length gives enough reach to pass through channel plus a bracket or spacer. Confirm your channel nut is 3/8-16 rather than 1/2-13 before ordering.

Indented hex head means the top of the hex is formed with a shallow dished recess from the cold-heading process. It doesn't change how you drive it, you still use a standard 3/8-16 hex bolt socket or wrench on the flats. It's a manufacturing characteristic of the head, not a drive feature.