A method of injection molding a catheter assembly, the method comprising providing a mold having an elongated cavity in the form of an external surface of the catheter assembly, providing a core pin in the longitudinal axis of the catheter assembly inside the cavity in the form of an inner lumen of the catheter assembly, where the core pin has a distal end that is fixed in place and a proximal free end, providing a first and a second molding member where each one of the first and the second molding members has a fixed end and a free end, in a radial direction of the elongated cavity, preparing the mold by arranging the free ends of the two molding members to support the core pin, injecting a liquid catheter material into the mold, letting the liquid material solidify.