This Ingersoll Rand air impact wrench was introduced over 25 years ago and has been continuously refined. It offers the sheer power and performance to tackle tough jobs with ease. Drive (in.): 1/2, Average Air Consumption (CFM): 4.2, CFM at Load: 22, Speed - No Load (RPM): 8,000, Blows Per Minute (BPM): 1,200, Max. Torque (ft.-lbs.): 425, Working Torque (ft.-lb.): 25 - 230, Inlet Size (in.): 1/4, Min. Hose Size (in.): 3/8, Hammer Mechanism: Twin, Standard Bolt Capacity (in.): 9/16, Variable Speed: Yes