To Find :
The torque of the stud.
Solution :
We know, torque can be calculated by force and distance between the center and force applied.
So,
[tex]\tau = F\times R\\\\\tau = 40 \times 0.5 \ N .\ m\\\\\tau = 20 \ N .\ m[/tex]
Therefore, the torque on the stud is 20 N m .