Abstract: A mold assembly (100) for making tubular articles. The mold assembly includes a core plate (210), core inserts (230) mounted to the core plate (210) by fasteners (B), a cavity plate (410) with holes (413) through its thickness and cavity inserts (420) mounted to the cavity plate (410). Each core insert (230) has a molding surface (234a) and an engagement taper (233) between the molding surface and its mounting surface (236). At least part of the engagement taper (233) is located closer to the mounting surface (236) than it is to the molding surface (234a) for inhibiting the core insert (230) from tipping when the engagement taper (233) is engaged to move or slide the core insert (230) along the core plate (210).