<p>I'm working on a gadget a bit like a jewelry box. I want the lid on a hinge. Are 3d printed hinges robust enough for daily use long term? Perhaps with a metal pin?</p>
<p>I want to incorporate the hinge into the design but my thinking is that it would be a waste of time if the hinge will break as I'd need to reprint the whole gadget.</p>

More detailed information would be valuable. A hinge the size of a soft drink can is going to be stronger than that of a pencil, generally speaking.
A substantial portion of determining the strength of a specific printed object relies on the layer orientation and of the material from which the object is printed.
Consider to examine others' creations on sites such as Thingiverse and PrusaPrinters to see how the result fare against your objectives. I've noted that the better designs will have substantial wall thickness to the barrel portion of the hinge. Additionally, if one can print the hinge with the cylinder axis oriented vertically, the layer lines will "encompass" the pivot. This provides the better strength characteristic of the layer.
The pin aspect is not as important when considering strength, although a 3D printed pin can be weak if printed vertically.