Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2796373.

As I was building a small prusa style printer, I wanted the leveling screws a bit out of the way. This is the result. Fits for a alu heatbed 3mm thick. Goes over the corners and has a thight fit. Accepts a M3 nut. See pictures.

I printed these in Polycarbonate with a 0.6mm nozzle as I want to print ABS too with this one. If you just need to heat up to 80°C, ABS will do too (red ones in the picture).