This is a snap lock I created to hold some cabinet doors. You print out a male and a female, and you mount one on each object, and they snap together.

The snap lock is very tight so you might want to carve them out a bit you you are using them in a place where they should not snap so hard.

I only tried them i PLA, so I do not know how they would behave in other materials. I printed them using 30% fill. I think less would work just as fine or better.