Assembly group for a press fitting, having: - a substantially cylindrical ferrule with a pressing region; and - a stop ring which is secured to a first axial end of the ferrule and delimits the pressing region in an axial direction of the ferrule, wherein the stop ring has the following: - a first internal contour on a side opposite the pressing region, for attaching the assembly group to a fitting body of the press fitting; - a first circular segment and a second circular segment, adjacent thereto, that extends over a smaller part of the first internal contour than the first circular segment; - a cross section, which is constant in the region of the first circular segment, with a bevel having a clear inside diameter that decreases from the side opposite the pressing region in the axial direction of the assembly group; and - an element which is arranged in the region of the second circular segment and projects inwards beyond the constant cross section of the first circular segment, characterized in that - the element arranged in the region of the second circular segment has an insertion chamfer, and - an inclination angle of the insertion chamfer is greater than an inclination angle of the bevel, in each case with respect to the axis of symmetry (A S) of the assembly group, and/or a surface of the insertion chamfer is arranged so as to be offset inwards in a radial direction with respect to a corresponding surface of the bevel, such that when the assembly group is attached to the fitting body, the element causes an axis of symmetry (A S) of the ferrule to be tilted relative to a central axis (A F) of the fitting body. - a substantially cylindrical ferrule with a pressing region; and - a stop ring which is secured to a first axial end of the ferrule and delimits the pressing region in an axial direction of the ferrule, wherein the stop ring has the following: - a first internal contour on a side opposite the pressing region, for attaching the assembly group to a fitting body of the press fitting; - a first circular segment and a second circular segment, adjacent thereto, that extends over a smaller part of the first internal contour than the first circular segment; - a cross section, which is constant in the region of the first circular segment, with a bevel having a clear inside diameter that decreases from the side opposite the pressing region in the axial direction of the assembly group; and - an element which is arranged in the region of the second circular segment and projects inwards beyond the constant cross section of the first circular segment, - a first internal contour on a side opposite the pressing region, for attaching the assembly group to a fitting body of the press fitting; - a first circular segment and a second circular segment, adjacent thereto, that extends over a smaller part of the first internal contour than the first circular segment; - a cross section, which is constant in the region of the first circular segment, with a bevel having a clear inside diameter that decreases from the side opposite the pressing region in the axial direction of the assembly group; and - an element which is arranged in the region of the second circular segment and projects inwards beyond the constant cross section of the first circular segment, - the element arranged in the region of the second circular segment has an insertion chamfer, and - an inclination angle of the insertion chamfer is greater than an inclination angle of the bevel, in each case with respect to the axis of symmetry (A S) of the assembly group, and/or a surface of the insertion chamfer is arranged so as to be offset inwards in a radial direction with respect to a corresponding surface of the bevel, such that when the assembly group is attached to the fitting body, the element causes an axis of symmetry (A S) of the ferrule to be tilted relative to a central axis (A F) of the fitting body.