Needle holder (20) is slidable in a sleeve (30) with a proximal end opening and distal and neck (32) between needle retracted and extended positions. The holder can be permanently locked with the needle in the sleeve by an annular projection with flexible segments (36) extending from the sleeve interior about its proximal end. Each segment is angled to expand under pressure. A groove (26) in the holder distal end receives the segments to lock holder and sleeve together due to segment expansion in the groove. The sleeve pref. has a proximal end inward annular support (38) for the holder.
