Abstract: The process makes it possible to manufacture any zip fasteners, i.e. to mold sets of locking members of any length, of the staggered or slit type, the upper stop members, the coupling and the box in a single operation. The apparatus for injection moulding all these components comprises a two part injection moulding tool wherein strips with recesses for the forming of locking members are applied to both the lower and the upper part of the tool and the lower strips can be moved vertically. The transverse slide has in addition to recesses for the upper stop members and the recess for the coupling a mold part for the box, in which is located a mold body which can be displaced within the plane of the slide. In order to form locking members with slits the lower part of the tool is provided with a device to remove the insert which forms the slit from the slit when the finished zip fastener member is removed.