Abstract: A Bourdon tube sensing element for a fluid-filled temperature gauge is made by inserting strips of silicone rubber into a partially flattened tube, especially one of beryllium copper, which is shaped on a fixture or mandrel. The shaped tube is subjected to a heat treatment during which the silicone rubber expands and deforms the tube. After heat treatment, the tube is cooled retaining its shape and the silicone rubber contracts from the inner surface of the tube to form a small passage between the silicone rubber and the tube so that the pressure of the fluid may be uniformly applied to the interior walls of the tube.