Coupling fitting, having a pipeline and having a connector sleeve, wherein the coupling fitting has the following further features: - a radially outwardly pointing, encircling bead which is spaced apart from the end of the pipeline by a predetermined dimension, - a first end of the connector sleeve which is pushed onto the pipeline is arranged in the region of the bead of the pipeline and has a first inner diameter such that a gap is present between the outer diameter of the bead and the first inner diameter of the sleeve, and a second end of the connector sleeve has a second inner diameter which corresponds to the inner diameter of the pipeline, and the first inner diameter transitions into the second inner diameter in a transition region between the bead and the end of the pipeline, such that the sleeve is pushed onto the end of the pipeline only as far as a point at which the end of the pipeline fits no further into the second diameter of the sleeve, - an elastic ring-shaped seal, which is arranged both between the end of the pipeline and the bead and between the pushed-on sleeve and the pipeline, - a connecting ring which is arranged in a region which is axially dimensioned such that it covers the pushed-on first end of the sleeve both in the direction of the non-pushed-on second end of the sleeve and in the opposite direction by a predetermined dimension and is produced in a plastics injection-molding process, wherein the material of the connecting ring is, owing to the injection pressure, pre-pressed through the gap as far as the elastic seal and, secondly, the injected material is pressed around the pipeline behind the bead of the pipeline in a direction pointing away from the pipeline end, such that a shoulder is formed which extends inwardly as far as the pipeline. - a radially outwardly pointing, encircling bead which is spaced apart from the end of the pipeline by a predetermined dimension, - a first end of the connector sleeve which is pushed onto the pipeline is arranged in the region of the bead of the pipeline and has a first inner diameter such that a gap is present between the outer diameter of the bead and the first inner diameter of the sleeve, and a second end of the connector sleeve has a second inner diameter which corresponds to the inner diameter of the pipeline, and the first inner diameter transitions into the second inner diameter in a transition region between the bead and the end of the pipeline, such that the sleeve is pushed onto the end of the pipeline only as far as a point at which the end of the pipeline fits no further into the second diameter of the sleeve, - an elastic ring-shaped seal, which is arranged both between the end of the pipeline and the bead and between the pushed-on sleeve and the pipeline, - a connecting ring which is arranged in a region which is axially dimensioned such that it covers the pushed-on first end of the sleeve both in the direction of the non-pushed-on second end of the sleeve and in the opposite direction by a predetermined dimension and is produced in a plastics injection-molding process, wherein the material of the connecting ring is, owing to the injection pressure, pre-pressed through the gap as far as the elastic seal and, secondly, the injected material is pressed around the pipeline behind the bead of the pipeline in a direction pointing away from the pipeline end, such that a shoulder is formed which extends inwardly as far as the pipeline.