Had to remove eight 3 1/2" dia coaxial bolts from pockets in bedplates, which had been in place since 1972 and were stuck fast. Two men on 6' tubes on both ends of a 3/4" tee bar couldn't shift any of them. This impact wrench got them out in 50 mins, one of the bolts taking 30 minutes to remove as the compressor couldn't keep up.The instructions state 175lb as the operating pressure, although we were at 125lbs.You will need a 100 series tail for the wrench and a 100 series socket for your compressor.