Forming gas is also used to regenerate catalysts in glove boxes and as an atmosphere for annealing processes. It is sometimes used as a reducing agent for low- and high-temperature soldering and brazing, to remove oxidation of the joint without the use of flux. Quite often forming gas is used in furnaces during annealing or sintering for the thermal treatment of metals, because it reduces oxides on the metal surface.[4] Forming gas is a mixture of hydrogen (H2) and an inert gas (usually nitrogen, N2) that is used to reduce oxides on metal surfaces to water.