Does any one know how to calculate the horsepower on an impact gun/wrench? Or can anyone at least give me an average horesepower range of an impact gun? The manufacter only give the torque. Also the manufacter only give the free speed of the gun? What would the RPM speed of the impact gun be if lets say your removing a lug nut off a car. Could I asssume that the blows per minute is equivalent to RPM under load? I need this information for my senior project in college. thanks?