Single-zone tube furnace with double-layer steel casing and air cooling keeping surface temperature below 60掳C. Features high purity ceramic fiber insulation for maximum energy saving, special refractory electrostatic coating on liner, and heating elements on support tubes for free radiation. Split cover with interlock protection cuts power when door opens during heating. Maximum temperature 1200掳C (inert gas required to resist deformation), vacuum heating up to 1000掳C. Heating rate 20掳C/min maximum. Total heating zone length 410mm with constant temperature zone of 150mm (卤2掳C).