Brazing vs Welding vs Soldering: What’s the Difference in Torches?

brazing steel and brass

Soldering, brazing, and welding all generally aim to do the same thing – join together two metals. There are differences among the three processes however in terms of heating temperatures as well as different use cases for each that we will briefly discuss.

Welding

The two metals being joined together, most often with a filler metal, must be similar. Two different metals can’t be melted together to strong a tight bond at high temperatures otherwise. In other words, if you need to join copper and aluminum for example, you should use a brazing torch.

There are a number of different types of welding such as laser, electronic beam and metal insert gas (MIG) welding. They all aim to either join together two metals or, conversely, to melt through them and slice them apart.

Brazing

Brazing uses a hot flame and filler metal to join two pieces of metal together as well. The metals, however, can be dissimilar.

This is because rather than melting together the metals into a pool, brazing involves using a filler metal to join the two pieces of metal together.

This filler (alloy) is called flux and is a liquid that melts at relatively low temperatures that flows over the two pieces being bonded together. Flux has the added benefit of cleaning the metal surfaces to facilitate a tighter bond.

Brazing is great for joining dissimilar metals but welding actually forms stronger bonds between two (alike) metals.

Brazing is widely used by plumbers , auto mechanics, and even by cooks and artists who work with bronze structures.

Soldering

This is the lower temperature version ( < 840 degrees) of the two aforementioned techniques that are used to join together (usually) smaller metal parts via filler metals.  Its typically used by those working on computer motherboards so low heat is used to keep from potentially damaging the computer’s sensitive parts.

The bonds are obviously not as strong but the point is to connect together small electrical components, not 4 inch think aluminum rods.

Brazing is used in numerous automotive applications, jet engines, cookware and utensils, and HVAC systems, to name a few.