Device having a quick coupling system for fastening an exchangeable head comprising: - a tool body with a cylinder, wherein a main piston is capable of being moved inside the cylinder under the effect of an injection of pressurised fluid into the interior of the cylinder, the tool body extending longitudinally along a tool axis; - the quick coupling system arranged at a free end of the tool body wherein the quick coupling system is with: an actuation unit, and a locking unit adapted to secure the exchangeable head to the tool body, wherein the locking unit is actuated by the actuation unit between a locking position and a release position, wherein in the locking position the locking unit is adapted to secure the exchangeable head to the tool body, such that transmission forces can be exchanged between the exchangeable head and the piston, and wherein in the released position the locking unit is adapted to release any force applied to the exchangeable head in order to remove the exchangeable head, and characterised in that the locking unit comprises a first and a second half ring (34a, 34b), wherein the half rings are radially movable between the locking position and the released position, and and in that the quick coupling system further comprises a sleeve slidingly arranged around the quick coupling system, the sleeve being movable along the tool axis, and the actuation unit is connected to the sleeve and adapted to be radially moved by the sleeve from a rest position to an active position, wherein in the rest position the half rings (34a, 34b) are in the locking position, and in the active position, the half rings (34a, 34b) are forced in the released position. - a tool body with a cylinder, wherein a main piston is capable of being moved inside the cylinder under the effect of an injection of pressurised fluid into the interior of the cylinder, the tool body extending longitudinally along a tool axis; - the quick coupling system arranged at a free end of the tool body wherein the quick coupling system is with: an actuation unit, and a locking unit adapted to secure the exchangeable head to the tool body, wherein the locking unit is actuated by the actuation unit between a locking position and a release position, wherein in the locking position the locking unit is adapted to secure the exchangeable head to the tool body, such that transmission forces can be exchanged between the exchangeable head and the piston, and wherein in the released position the locking unit is adapted to release any force applied to the exchangeable head in order to remove the exchangeable head, and characterised in that the locking unit comprises a first and a second half ring (34a, 34b), wherein the half rings are radially movable between the locking position and the released position, and and in that the quick coupling system further comprises a sleeve slidingly arranged around the quick coupling system, the sleeve being movable along the tool axis, and the actuation unit is connected to the sleeve and adapted to be radially moved by the sleeve from a rest position to an active position, wherein in the rest position the half rings (34a, 34b) are in the locking position, and in the active position, the half rings (34a, 34b) are forced in the released position.