bought a cabinet, didn't have a key... I made one. it works. I used it then to go to the flea market and find a similar sized key that I could cut down with a dremel to match and now I have a metal key. Of course you could print it in metal if you have a really expensive printer.

Printed it in PLA, break off the support used to keep the PLA from becoming toxic nozzle glue, put the shaft of the key into the handle, the little protrusion snaps into a matching divot inside the handle and keeps it from spinning.... and then will hopefully let it spin before breaking off if you happen to jam it.