Tubothal Heating Element Kanthal´s outstanding metallic element heaters for use inside all types of radiant tubes, ideally Kanthal APM. Available in standard dimensions from 68 to 170 mm diameter 2.6 - 6.6 in. Power up to 40 kW/metre length, 12.2 kW/ft. The use of APM wire is the reason for the high performance of the TUBOTHAL elements. The life at 1000°C 1830°F furnance temperature is more than double that of NiCr wire.