Old SNAP-AITM screws

Older SNAP-AITM modules (circa 2010) had four Philips screws for the field wiring (new modules (and really old modules) had/have captive screws). What size are these old screws? One was lost.

Do you mean these field termination screws?

Beno, those field termination screws are the captive screws on the more modern SNAP-AITM modules. Go back one generation of SNAP-AITM module and the Philips field termination screws found are like in this picture (and the specification I need)

Ah, thanks for the clarification.
The screw you seek is 6/32 thread and 3/8 long.