The invention relates to a hydraulic unit for a mobile hydraulic tool with a hydraulic piston hydraulically adjustable between a starting position and an end position and a piston rod that is connected to the hydraulic piston and has a tool holder for a tool insert. In order to provide a hydraulic unit for a mobile hydraulic tool that enables the use of tool inserts with different load bearing capacity, it is provided that a pressure control valve connecting the pressure chamber to a cylinder chamber and limiting the pressure acting on a hydraulic piston on the pressure chamber side is arranged on the hydraulic piston and is connected to the piston rod such that a response pressure of the pressure control valve can be adjusted by the piston rod.