The vacuum ovens provide a space where the pressure is below the atmospheric pressure always. A particular environment where the atoms have the chance to travel trajectories longer before colliding, rarefied, clean, non-polluting and with the possibility to work in the absence of oxygen. The vacuum ovens are mainly used in the heat treatment of steels and various alloys for operations of quenching, tempering, annealing. They are used for brazing processes that can weld several pieces using filler metal without deformation of the final piece. Also used in sintering processes in which the pieces formed from powders of metals or ceramics pressed, are brought to the phase of coalescence at very high temperature and from this to the final form with a controlled cooling.