An electrical plug connector comprises an insulating plastic base and a first and second series of elongate metal contact security respective opposite major faces of the base by an in-molding step so that respective back surfaces of the contacts and parts of their side surfaces are embedded in the plastic material while connecting surfaces are exposed for engagement with a complementary connector. During the in-molding process a cavity is formed between the two series of contacts at a rear end of the base by a mold member supporting rear ends of the contacts of respective series in spaced apart, parallel relation while front ends of the contacts are supported by attachment to respective carrier strips. A plug is force fitted into the cavity subsequent to molding supporting the rear ends of the contacts. Leading, front ends of the contacts have laterally extending anchoring portions and tapering, inwardly extending tips completely covered by the plastic material to ensure double securement to the base.