A pneumatic torque wrench is a planetary torque multiplier or a gearbox that is mated to a pneumatic air motor. At the end of the gearbox is a reaction device that is used to absorb the torque and allows the tool operator to use it with very little effort. The torque output is adjusted by controlling the air pressure. The pneumatic torque wrench is sometimes confused with a standard impact wrench, due to their similar appearance. A pneumatic torque wrench is driven by continuous gearing, and not by the Hammers of an impacting wrench. A pneumatic torque wrench has very little vibration, and excellent repeatability and accuracy.
