Stainless steel can be satisfactorily brazed using silver brazing filler metal with the proper fluxes. Ordinary steel flux or borax will not successfully remove the scale formed on the surface when heated, and so will prohibit any bond between the braze material and the steel. The filler metal will ball up, resembling water drops on an oiled surface, and will not adhere. Special fluxes for stainless steel are available which, when used dry or in a water paste applied to the surface before heating, will eliminate this difficulty because they fuse and protect the steel from the formation of an oxide on the surface.

Low-melting silver braze alloy is preferred over those melting at higher temperatures because it reduces the tendency to form scale and also reduces warping. It is advisable to heat the rod and apply dry flux in addition to the original paste or dry powder on the steel itself. When brazing sheet metal, overheating the metal must be carefully avoided, because copper brazing alloys will penetrate entirely through the sheet following the grain boundaries, resulting in checks or cracks upon cooling. See SILVER ALLOY BRAZING.

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