Folding corners (180°) for aluminum tubes 20x20

Folding corners (180°) for aluminum tubes 20x20, with hole for cable passage (6mm) in two possible versions.

FILE

P20x20 GM B (without cable hole) bolt side
P20x20 GM D (without cable hole) nut side
P20x20 GM C1B (with type A cable hole) bolt side
P20x20 GM C1D (with type A cable hole) nut side
P20x20 GM C2B (with type B cable hole) bolt side
P20x20 GM C2D (with type B cable hole) nut side

I used 5mm bolts and nuts, but in the next version I suppose to make it, without bolts and nuts, printable in place.

Extension of my previous project.
https://www.thingiverse.com/thing:6710864

Last, but not least.