The invention relates to an interface between two parts of a tool system, in particular to a metal cutting tool (1). Said interface comprises a holder (3) provided with a cavity (31), an interchangeable head (5) which is arranged on the axial extension of the holder and provided with a projection (33) introducible into the cavity (31) and a clamping device (19) for fixing the interchangeable head (5) to the holder (3). The inventive interface is characterised in that the clamping device (19) is provided with a holding bolt (41) and an eccentric element (21) which axially displaces said bolt and is actuated through a peripheral surface (17) of the metal cutting tool (1).