An arrangement contains a brake piston for operating at least one disk brake pad and a nut-and-screw unit for producing an axial thrust, from the rear to the front, of the piston containing a nut arranged in the piston's interior, and secured thereto to prevent rotation, and mounted therein to slide axially, whose front axial end face interacts with an internal section facing the piston's front wall to push the piston axially towards the front when the screw is rotatably driven in the unscrewing direction, and the screw containing a front section screwed into the nut, an intermediate radial flange and a rear section, wherein the piston screw contain centering elements that interact with one another when the screw is in a predetermined front axial mounting position in relation to the piston in order to center the rear section of the screw radially in relation to the piston.