The most versatile of all electric heating elements, the tubular heater is capable of being formed into virtually any configuration. The range of ratings, sizes, materials and terminations available makes the tubular heater adaptable to many industrial, commercial and scientific applications. The basic design consists of a helical coil of nickel-chromium resistance wire precisely centered in a metal sheath. This coil is surrounded by magnesium oxide powder which is vibration loaded to insure even density throughout the length of the heater. This entire assembly is then roll reduced or swaged to the finished diameter, compacting the MgO and "centering" the coil in the center of the heater. A sealant is applied at the terminal end to retard moisture absorption during the initial period of storage.