A ``zigzag'' type of spring for supporting current‐carrying filaments is described and compared with the tungsten helical type of spring. The zigzag spring is particularly useful when a combination of high current‐carrying capacity and low spring constant is desired. Designs and stress analyses are deduced both for the helical and the zigzag spring, to meet a wide range of requirements. An approximation is given for the elastic limit of molybdenum and the rolling and annealing of molybdenum sheets for tube parts are discussed.