Abstract: A pneumatic hand tool comprises a tool body communicable with an operating air source, a pneumatic motor supported by the tool body, and a control valve for controlling air flow to the motor. When the control valve is in an open condition the motor is operated to drive the tool. When the valve is in a closed condition it cuts off the supply of operating air to the motor. In the closed condition the control valve communicates with air at ambient atmospheric pressure so that source air leaking from the control valve is vented away from the motor to preclude unintended motor operation.