Brazing versus Soldering

Brazing versus Soldering



Welding Challenged asks:  "Are both soldering processes? Silver soldering being a specific process, where brazing is a more generic term? Isn't brazing normally a melted bronze soldering process? An oxy-acet. torch being necessary to achieve the temps necessary to get the bronze(?) to flow without(!) melting the parent metals? Thanks for helping a welding challenged person."

Tin Man answers:

Brazing may be done with a variety of the following metals: brass, bronze, silver, aluminum, copper....etc. Silver soldering is differentiated by temperature into two processes: soft soldering at temps below 650F using lead-cadmium-antimony-silver alloys , and hard soldering above 850F using copper, tin, nickel, zinc, silver alloys.

Alloying silver with other metals changes the melting point, adhesion and wetting characteristics, and tensile strength. Of all the brazing alloys, the silver solders have the greatest strength and the broadest applications.

Braze-welding is another term which covers joining one group of similar alloys, having different melting points. Joining at a point where the parent metal does not melt is brazing, whereas joining its neighbor, which has a slightly lower melting point, actually melts it, and welding now occurs.

IE: brazing using a brass alloy (yellow brass) on nickel brass is truly brazing for the NiBrass does not melt, but to braze a yellow brass faucet casting with the same brazing material causes the faucet base metal to melt, hence braze-welding or brass welding . You see, it's all based on melting points.

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