Hydraulic impact wrench is a powerful, lightweight impact wrench that excels in hard to reach places and confining areas. It is used for tightening the bolts are separate hand-held machine connected to the main hydraulic tank by flexible tubes. The torque is actuated by the rotary impact mechanism. The wrench-driving unit consists of the gear motor driving the impact mechanism. The throttle screw located in the wrench handle makes the control of the tightening moment.