A locking component (100,200,300,400) for locking a catheter proximal end onto a stem (16,56) of a medical device. The locking component has upper and lower parts (104,102204,202) that self-secure to each other, preferably in a first position partially open but still assembled, and a second position, locked fully together. The locking component has a compression surface (106,206) to compress the catheter lumen wall against the stem at a location axially offset from the protuberance(s) along the stem of the medical device. A method is disclosed for mechanically securing a catheter to a medical device that can involve placing the pre-assembled locking component along the catheter prior to securing the proximal catheter end to the stem of the medical device and then moving the locking component into position around the stem and then pressing it together into its second locked position, compressing the catheter lumen wall against the stem.
