9.5mm Square Hole M5 Screw Insert (License Plate, etc, inc Fiat 500/500ee)

thingiverse

The license plate on my new-to-me Fiat 500e was missing the inserts for the lower bolts that retain the plate. The holes were 9.5mm square and I didn't have any square bolts. Instead I made these inserts. Print as loaded, no supports. I print two at a time to keep them from overheating as it's pretty small. After printing, break off the support (there's a handy flat spot that prints on the bed). Then get one side in the hole, push good and hard to the side and then in, and with a decent POP, in it goes. I was able to drive M5 bolts directly into these without issue. I printed mine in PETg but imagine other materials would work. If it's too tight, take a tiny bit of horizontal expansion out or scale a few percent. I wanted a snug fit, so I print as is and push harder to install.