A hollow body composed of an electrically conducting material and extending longitudinally along an axis is connected at one axial end to a connection element composed of an electrically conducting material and extending along the axis. A first thread is provided on the hollow body at the one axial end running about the axis, while a second thread is provided on the connection element running about the axis, so that the second thread is mechanically supported by the first thread. An insulation-material extent between the first thread and the second thread electrically isolates the hollow body from the connection element.