I don't know, I just saw 'em and file 'em til they are right! I've never measured them!
Actually, I have one here that I'm redoing. It has a sight notch (the dovetail is not raised...yet) that is.... .055" deep.
I did this one like 20 years ago. If I were doing it now starting from scratch, I think I'd make it a little shallower, but it's fine.