I know the formula T=F*D but having problems wrapping my head around this problem. I want to direct couple a stepper motor with a .5"D shaft to a .75"D ballscrew. The motor has 400 oz inch torque but since the motor shaft is .5"D or .25" radius How do I calculate the Torque at .25" radius? I would think the force at .25" would be greater than the torque at 2"D In this case is the torque at .25 also the force F? Please provide the math in your answer.