Steel thumb bolt

3D-printed screws and threads are not perfect and also not very sturdy, even when printed with more perimeters and increased fill. 

Therefore I've designed this bolt and nut where a real steel M5 nut and M5x20 hex-head screw are used.

Assembly is easy - insert a bolt or nut into the corresponding plug and glue it to the base part. I have used super-glue and it works well.

Only the bolt-plug needs supports, but it would probably work without them. 

The bottom fill pattern is set to concentric for aesthetic purposes.