The role of a flux in joining processes is typically dual: dissolving of the oxides on the metal surface, which facilitates wetting by molten metal, and acting as an oxygen barrier by coating the hot surface, preventing its oxidation. In some applications molten flux also serves as a heat transfer medium, facilitating heating of the joint by the soldering tool or molten solder.
303 :- For use in braze welding & brazing of copper & steel. Also used for braze welding on cast iron & fusion welding of copper, brass & bronze.
602 :- For low temperature silver brazing, provides quality joints in station less, copper, brass & bronzes.
801 :- Specially formulated for soldering stainless steel, monel & nickel & can also be used for copper, brass & tin. This flux can be used on most metals (excluding aluminium, magnesium & die cast). Commonly used in radiator repairs, plumbing & industry.