Just some added details to avoid confusion and buying the wrong stuff.... There are basically two ways of joining metal using heat - welding and soldering. WELDING entails heating the "parent" metal of both parts to be joined until they melt and flow together (usually adding filler material in the form of welding rods). The most common types of WELDING are "Shielded Metal Arc Welding (SMAW or stick)", "MIG" and "TIG". WELDING is mostly confined to joining like metals (steel to steel, stainless to stainless, cast iron to cast iron, aluminium to aluminium, etc) but can be used for dissimilar metals - if you really know what you're doing....! SOLDERING differs very much from welding in that the parent metals are not melted but only heated sufficiently for (a) the SOLDER to melt and (be) for rmetallurgical bonds to form between the solder and the parent metals. (Essentially a sort of "gluing" process with the solder being the glue). The term "soldering" originally referred to the PROCESS itself irrespective of what metal was used as the "solder". It didn't really matter what it was as long as (a) its melting temperature was less than that of either parent metal and (b) it was metallurgically compatible. However, over time the term "soldering" has become associated with the joining of NON-FERROUS metals (copper, brass, bronze, gold, silver, etc) mostly using various alloys of lead, copper, tin, silver, gold and even ALUMINIUM as solder. Because joining of ferrous metals by means of a SOLDERING (as opposed to WELDING - see above) process has typically been done using a copper based alloy (brass or bronze brazing rods) as solder this has been generally become known as brazing with the term "brazing rod" being reserved for the brass/bronze rods used.
There are several methods available for joining metals, including brazing and soldering. What is the difference between brazing and soldering? Let’s explore the distinctions plus comparative advantages as well as common applications. This discussion will deepen your understanding of metal joining and help you identify the optimal approach for your application. HOW BRAZING AND SOLDERING WORK Brazing and soldering join materials, usually metals, together by flowing a filler metal into the joint. In both cases the filler metal has a lower melting point than the base metals being joined. And for both metal joining processes, capillary, or the ability of a liquid to be drawn through a narrow gap, is the driving force. Gaps can vary, but in general they tend to be in the range of .002-.005" for best results. So what is the difference between brazing and soldering? The American Welding Society (AWS) defines brazing as a group of joining processes that produce coalescence of materials by heating them to the brazing temperature and by using a filler metal (solder) having a liquidus above 840°F (450°C) and below the solidus of the base metals. Soldering has the same AWS definition as brazing, except that the filler metal used has a liquidus below 840°F (450°C) and below the solidus of the base metals. Soldering can be considered the low-temperature cousin to brazing. Comparative Advantages. Although there are similarities between brazing and soldering, the temperature difference between the processes yields different behavior. Base metals involved in soldering are typically stronger than the solder itself; under the stress and fatigue of service, failure may occur through the solder joint. This means a that a soldered assembly may exhibit less joint strength and lower fatigue resistance than a brazed assemb
