Summary

This model is a remix of the sanding block proposed by micmac2a and Joew1120:
https://www.thingiverse.com/thing:4639552
https://www.thingiverse.com/thing:4793489

In this version the printed screw has been modified to support more torque and be stronger. To that end the screw is longer, has a larger diameter and use a different threading. The tolerance between the base and the screw is also smaller.
This also makes the model easier to print as the small features are bigger.
From my experience it make a good job of strengthening the part and i couldn't waste the new treading by hand.

EDIT: Following the comments of people having difficulties with the printed screw i added two new files: "Screw 0.8 clearance" and "Screw 1.2 clearance". Those files are designed to be used if your printer tends to over extrude. The clearance of the original "Screw" file is 0.4mm. It is better to use those files that to rescale the whole part as here only the threaded part is modified. Just be reminded that your assembly will be strongest when the screw just fits in the threaded hole with minimal clearance.