Manufactures normally don't include anything like this and the working space is normally pretty limited, I printed in PLA with 100% infill at 0.3 layer ress , it is quiet strong and was able to remove a very VERY old tap mixer.
the tolerance in the central hole is quiet thight because I wanted the maximun torque, feel free to modify the file and increase the tolerance around 0.1-0.2 mm
hope it helps someone as much as it helped me.
The author marked this model as their own original creation.