Certain types of drills and drivers can produce enough torque through reduction gearing that manufacturers include an overdrive clutch between the tool spindle and the motor. This is done to avoid scenarios where the tool can overpower the user or a component in the transmission of the tool could be damaged.
When a threshold torque is surpassed, the overdrive clutch can open and reduce or eliminate the torque that is transmitted through the clutch. By reducing the torque, the user can continue to hold the tool and/or can avoid possible damage to the transmission. Notwithstanding, the overdrive clutch can be relatively large, it typically includes many components and can be relatively complex. A relatively high part count and associated complexity can add additional costs to the tool.