The simple object to test the maximum overhang 3D printer can deal with. The angles are, top to bottom:

90°
80°
90°
70°
90°
60°
90°

180°

90°
55°
90°
50°
90°
45°
90°
40°
90°
35°
90°
30°
90°

In short, the bottom part is 80,70,60 that should work on every machine and the top part is 55-30 in 5° steps so you can then find what overhead angles you can "live with", what the "good" ones are and what angles are unprintable.

EDIT:
I have now added also a test_overhang_flat.stl after imho valid comment that overhang on the round and flat surface is not same, so here's the one to test the flat overhang.

One side (right) is 60, 55, 50, 45° (with 90° in between) and other side (left) is 40,35,30,25,20° (with 90° in between).

Print the object - without support

There is also stl with only "TOP" part that is problematic so with overhang below 60° if you do not want to print the whole object as you know machine will work ok with up to 60°.