Use this piece to keep a hinged thing closed, and easily open it again.

100% 3d printed, no other parts required. Useful only in low-load scenarios where not very much stress will be placed on the hinge.

There is a slot in the "bar" part of Swing_arm: to increase reliability of the part, I recommend you glue a small strip of a rubber band into this slot. The rubber band will act as a sort of gasket, creating a nice firm clasp.

To use this in your design, simply attach the Upper_body to one side (the lid of a box, for example) and the Lower_body to the other side (the box itself). All parts use a 0.3mm tolerance, which seems to be perfectly fine on my Replicator2.

I designed this piece using parameters for all the part dimensions. Please feel free to create your own copy of it, referencing this original design (on Onshape):

https://cad.onshape.com/documents/25a0030f578829beaae4c241/w/cbd25f7e0fa6d4bc3185259f/e/5ca28f4bab31b54132a18182?renderMode=0&uiState=63af009271939f621fa7809b