As I didn't see anything published here, here is how I measured the torque requirements and what the motors can deliver.

The ID is 5mm, the common diam of Nema17 and extruder shaft.
Use a flat M3 grub screw, drill to 2.5mm, no need to tap.
I added a steel shim but it is not really necessary.

Drill a 1mm in the flange, thread in a piece of spectra or fishing line (about 20cm), from the inside of the pulley, then a knot. Make a loop for the scale at the free end.

As for its use, the picture is self explanatory. For motor, it will wind up the thread, for other measures wind up some turns and pull.

The pulley has a 2cm diam, so what you read on the scale is the torque in kgf.cm multiply by g if you are picky or simply by 10 to get it in N.cm.

Now you can measure the torque you need to move your table, gantry, extruder etc... and what your motot can deliver and adjust its current accordingly.
OK, its static, keep that in mind when adjusting your motor current.