NOVELTY - The mold part comprises two part elements (1, 2) from electrical conductive composite material that consists of plastic and electrical conductive filler, where graphite is used as filler. The part element comprises contact surfaces (3, 4) and the filler is bounded in a thermoplastic plastic. The part elements are welded together at its contact surfaces. Conductive- and/or property changing additive is used as filler. The mold part is produced by injection molding technique, injection stamping technique or hot-pressing technique. The mold part comprises two identical part elements.    USE - Mold part useful for producing highly conductive articles for a wide variety fields such as electrical contact plates for electrolysis purposes or bipolar plates for fuel cell applications.    ADVANTAGE - The mold part can be produced with high electrical and thermal conductivity and chemical resistance, high porosity and very low ductility.    DETAILED DESCRIPTION - The mold part comprises two part elements (1, 2) from electrical conductive composite material that consists of plastic and electrical conductive filler, where graphite is used as filler. The part element comprises contact surfaces (3, 4) and the filler is bounded in a thermoplastic plastic. The part elements are welded together at its contact surfaces. Conductive- and/or property changing additive is used as filler. The mold part is produced by injection molding technique, injection stamping technique or hot-pressing technique. The mold part comprises two identical part elements. The part element is a bipolar-half plate for polymer electrolyte membrane fuel cell. The filler portion of the composite material is 20-95 wt.%. INDEPENDENT CLAIMS are included for:    (1) a method for joining mold parts having part elements; and    (2) a device for the production of a mold part.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a mold part.    Part elements (1, 2)    Contact surface. (3, 4)