Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4389740. This hinge uses an M4 screw (30mm or longer) as the hinge pin, and has 4 countersunk mounting holes which also suit M4 screws. The assembled hinge is 30mm x 40mm x 18mm. When the hinge is folded back, it gives 25mm clearance between the two mounting surfaces (e.g. to clear handles etc) The mounting holes are spaced 20mm apart, and positioned 13mm from the edge of the panel where the hinge is fixed. This is symmetrical, so you just print the same STL twice to get the two halves of the hinge. I used an M4 x 30mm screw for the hinge pin (without a nut).