Abstract: An electron discharge device such as an X-ray tube having a filamentary cathode arranged to discharge electrons onto an adjacent anode wherein the filament is an elongated member fixed at its ends to respective filament support posts which are each mounted within a metal eyelet fastened within the bore of a nonconductive sleeve, respective lead wires being connected to opposite ends of the posts by flexible metal connectors whereby upon applications of heat to the assembly mechanical and thermal stresses, as might normally cause distortion of the parts and particularly of the filament, will be absorbed by the connectors.