A method of manufacturing a clamping ring for a cold-expansion joining system includes providing an extruded pipe part made of a cross-linked polymeric material where, while extruding the pipe part, the inner diameter is formed bigger than the outer diameter of a flexible cross-linked polymeric pipe onto which the clamping ring is positioned before making a pipe connection; providing an injection molded annular part having an inner diameter formed smaller than the inner diameter of the extruded part; and bonding the parts together to form a clamping ring having an inward protruding stop edge at one of its ends. The embodiments further relate to a clamping ring formed from an extruded pipe part made of a cross-linked polymeric material and an injection molded annular part bonded together to form a unitary structure including an inward protruding stop edge at one of its ends.