Device and process for covering an insert with plastic

An insert(10) is placed in a molding tool having a core and a mandrel(20) with centering pin(22). The centering pin and mandrel are held in the tool which allows them to move axially towards the insert and simultaneously rotate as they are screwed into an opening(18) in the insert. At the free end of the centering pin(22) facing the insert there is a self-cutting thread(32) for screwing into the tapered insert opening(18). During screwing in and out of the pin the mandrel rotates through 30-180[deg], preferably 45[deg]. The mandrel and centering pin may be spring-loaded in the axial direction. Pegs(19) at the front end(16) of the insert(10) facing the tool supporting the insert on the core when screwed into the latter. For sealing around the outlet area of the mandrel and centering pin the end face of the tool facing the insert has compression lips. Recesses for receiving contact pins(12,14) are also located in the end face of the tool. Rotational and axial movement of the mandrel and centering pin is by an ejection system(30). The insert is shaped(38) to prevent rotation. An independent claim is included for a process molding plastic around an insert, in particular a multi-pole electrical plug, in which the insert is pressed against the tool by screwing a centering pin on a tool mandrel into the insert.