Why need less torque while unscrew the bolt?

Less torque is needed when unscrewing a bolt because the initial tension and friction that hold the bolt in place are reduced as the bolt is loosened. Additionally, the mechanical advantage provided by the threads of the bolt allows for easier removal, requiring less force. Using excessive torque can lead to stripping the threads or damaging the bolt and surrounding materials. Therefore, a gentle, controlled application of torque helps ensure safe and effective removal.