Abstract: Impact tool and method for a hammer device that includes impact tool housing and tubular piston structured and arranged for axial displacement in impact tool housing via pressure medium. Tubular piston has essentially radial pressure surfaces structured and arranged on opposite portions of tubular piston to be acted on with pressure medium. Grooves are formed in impact tool housing that are structured and arranged for a reversal of a direction of a pressure medium impingement on pressure surfaces and discharge or recirculation of medium. Grooves include a control recess formed in tubular piston and at least two control grooves for a shift of pressure medium impingement on pressure surfaces that are arranged axially offset in impact tool housing. A controller is structured and arranged to alternatively activate one of the at least two control grooves via connection channels.