a process for producing a heating element comprising a heating wire wound as a bifilar spiral and arranged in a plastic part that can be welded to a plastic pipe by supplying electric current to radially outwardly extending wire ends of the heating wire . the process can be implemented with little effort , and the apparatus for carrying out the process enables functionally reliable production of the heating element . the heating wire is arranged in a bifilar spiral groove in a surface of an injection mold with the windings of the heating wire spaced a distance corresponding to the radial spacing of the individual windings of the spiral groove . after closing the injection mold , plastic is introduced into preferably radial connecting grooves between the windings of the spiral groove so that the plastic at least partially surrounds the heating wire in the vicinity of the connecting grooves .