This is a set of 3D shapes to make sockets for 3mm machine screws. Lengths are 5mm, 10mm, 15mm and 20mm. You can import these in your 3D design to use as Boolean Cutters or add as Shapes to PrusaSlicer 2.4 (or newer) to use as Negative Volume. If you add them to the Gallery in PrusaSlicer they’re always available for your prints.

I learned about these from a video by Thomas Sanladerer. Indeed, I adapted them from his design, for which I am grateful. As Thomas points out, 3D printing threads for screws as small as 3mm is difficult. This design lets the screw cut its own threads as you turn it.