Depends on who made the case.
To get something that works rather than is perfect :-
M1.4 x 2 most Rad lugs. Most need either a stop spacer machined in or an extra long head to bring it level with the case.
M1.6 x 3 or M2 x 3 for crown guard screws
The dificult bit on both is the head diameter, much smaller than DIN std spec.
As for screw bars, I've got at least six variations of thread, diameter, thread length etc. etc.
I even have two cases from the same factory, one SS and one Ti, that have differing, non-interchangable screw bars. Probably the reason so many get the threads stripped.