Don’t understand what you are asking. The standard 19” rack screw is a 10/32 thread and I know that Mid Atlantic sells Phillips head screws that are black and come in jars of 1000 or so. They also sell square bit rack screws that are the same for use in high security locations. Older racks sometimes used 10/24 thread and real old RCA racks used #8/24 screws.
I have old RCA racks that use 12-24 screws