The invention relates to a device and a method for producing a non-cylindrical inner surface (10) of a bore (4) comprising machining tools (9) which are arranged along the circumference of the bore (4) and can be radially advanced towards the inner surface (10) of the bore (4). The device comprises a primary advancing system (14) which comprises an axially movable advancing rod (13) for actuating the machining tools (9), thus exerting a primary force (F
Z ) onto at least one machining tool (9), the at least one machining tool (9) being radially advanceable towards the bore (4) by means of said primary force. The primary force (F
Z ) is dynamically superimposed with a secondary force which is generated by a secondary advancing system (16) that forms an integral unit together with the primary advancing system (14) or can be constructed in a modular manner. The secondary advancing system (16) is activated dependent on a current rotational movement and/or a stroke movement of the primary advancing system (14), a current tool position, or a specified advancing force, or the secondary advancing system is activated at a specified time. In the process, the tool is already widened by the primary advancement.