I'm currently making an enclosure from 4040 extrusions and couldn't find any hinge that would meet my satisfaction, so I've made one. It's completely functional with a very little play, since the tolerances are pretty small (check the drawing). You can install it by using M6 countersunk screws (and T-slot nut for extrusions of course).

I'll attach the .3mf file if you'd like to edit it for your needs.

I have printed it standing, with a smaller brim, just to be sure it doesn't fall. After printing, you may have to apply a very little force to break up any string between the 2 parts.