If you need to choose between brazing or welding, there are a lot of moments where the brazing option will be the superior choice. As someone who has been welding for many years, I recently really enjoyed some of the benefits that the brazing technique can bring to the end result of especially joining two types of metals together.
Don’t get me wrong, for the large majority of the welding jobs, the classical way to weld will do just fine. This is not an article to dismiss regular welding rods. On the contrary! This article is meant to emphasize some of the benefits and specific use-cases of brazing. The intention is to help you choose between the two welding techniques more easily.
What Is The Difference Between Brazing And Welding?
Brazing is the act of ‘gluing’ two pieces of metal together with a filler metal which melts at a lower temperature than the parent metal, keeping it fully intact. Welding requires both filler and parent metals to join the parent metal. The difference is that welding does not ‘glue’, but alters the parent metal.
Welding uses a filler metal composition that is roughly the same as the parent metal. Thus making it necessary to alter all materials involved in order to join them together. This all can sound quite confusing to beginners. Let’s take gas welding as an example and explain it in a YouTube video:
Benefits Of Brazing Over Welding
Not always will you *need* to choose to braze over e.g. soldering or other types of welding. But if you are looking for specific characteristics, such as achieving extra strength in a metal joint or perhaps you want to keep the original metal as intact as humanly possible, brazing can be a good option for your needs. When it comes to defining the positive elements of brazing, overall differences include the following:
- Strength: Brazed stainless steel joints can withstand pressures of up to 130,000 psi without affecting much of the physical properties of the metal joint. If you’re in need of a stronger weld, brazing is the best option.
- Control: Filler metal will flow and fill up the joint easily, regardless of the shape of the joint gap. You can increase strength further by changing joint width, making the filler metal act as a ‘superglue’. However, there is an optimal gap size (see chart here), which means that making the gap wider will decrease the ultimate strength significantly.
- Aesthetics: The parent metals will not be affected, as the melting temperature during the welding process will be too low. Instead, only the filler metal will have been affected. This allows for a cleaner joint and therefore a much prettier looking end result.
- Energy efficiency: As brazing is a lower-temperature technique, less energy is required to heat up the welding rod, making the process comparatively energy efficient overall.
- Preserving the base metal: As explained, regular weld techniques will also heat up and alter the parent metal, while brazing allows only the filler metal to be affected. This preserves the base metal while still providing greater strength.
In order to bring across the point of these benefits, let’s go ahead and dive a little deeper in each one. I think these explanations will convince every strength-focused welder out there to at least give this technique a chance. Let’s start with the most important factor, which is the immense strength improvement over regular welds. Very impressive stuff to say the least!
1. Brazing Is Stronger Than Welding
This is undoubtedly the most important reason why anyone would choose to braze their materials over the more regularly used techniques. The American Welding Society (AWS) puts this very eloquently on their article on the benefits of brazing techniques:
“A properly designed and brazed assembly will be as strong as the base materials being joined. Period. That means, if the brazed component breaks (fails) in service, the failure will be in the base material, away from the brazed joint.”
– American Welding Society (AWS)
This is shown over and over again in practice. The weakness of the metal will never be in the newly created joint, but more often than not in the metal itself. This alone showcases the immense pressure this technique can withstand, as well as the overall qualities of the technique. Just check out this fun strength test on aluminum materials by a YouTuber named Mathias Wendel, to get an idea of the possibilities:
2. Brazing Provides Much More Control
The key to controlling your weld lies in the fact that the parent metal does not melt in the process. You do not require a secondary weld due to this, also making it a much quicker process. However, there are many more factors that contribute to greater control. Here are a few of the major ones:
- You can braze two different types of metals together, even with a third type of metal filling to close the joint;
- You can also braze non-metals (such as metalized ceramics) to a piece of metal, which is not possible in regular processes;
- Heat distortion is limited compared to regular welding processes, due to the uniform heat distribution of the metal being brazed;
- Brazed materials can be coated or clad for reasons of protection, this is not possible or much more difficult in regular welding processes.
And we could go on for a while, but I think by now you get a general idea of the benefits. If you’re looking for a specific application of your weld job, make sure to consider brazing as well!
3. Brazing Produces A Cleaner Joint
One of the often cited core benefits is the improvement in terms of looks. Welding undoubtedly leaves a scar in the metal due to the heat affecting the metal. While strength is often not impacted, the looks of the metal sure are. This can be an issue when the aesthetics of the end result are important to the welder.
Artists, manufacturers and even the regular DIY welder will appreciate an improved look of the metal joints, as long as the strength of the joint will not be impacted. This is certainly not the case with brazing, as we have discussed extensively earlier in this article.
4. Brazing Uses Less Energy Than Welding
Production of a serious amount of heat for welding jobs is not only wasteful to some extent, but it will also drive up the cost quite a bit. When a decreased temperature (and therefore a lesser amount of energy) is used, the production cost of metal forging will be reduced.
This is especially interesting on an industrial scale. Not only for the reduction of environmental impact, but also because of the aforementioned reduction in energy costs. While a single job will not impact your wallet a lot, if you weld intensively on an industrial scale, this does indeed make a real difference.
Apart from this, the lower temperatures and energy used will also decrease the likelihood of common welding issues, such as the distortion and embrittlement of the heat-affected zone. This further increases the quality of the end product, making the use-case for braze techniques all the more obvious.
5. Brazing Keeps The Base Metal Intact
We’ve casually mentioned it in the other benefits multiple times. But it deserves its own section, because it is such a key feature ánd key benefit. Because a filler metal is used with lower temperatures than the base metal (i.e. parent metal), the end result will be less damaged and better looking.
Keeping the base metal intact can be a very important feature for different types of welding jobs, as sometimes the original metal can be brittle or weak already. These are the moments where braze techniques will outshine everything else. The filler metal strengthens and fortifies the base metals to be joined together. In the end, you’ll end up with one happy, strong and high-quality metal object. Perfect!
Disadvantages Of Brazing?
Of course, brazing also has its disadvantages. Not all welding jobs are suitable for brazing. Furthermore, it is possible that brazed joints can be damaged more easily in higher temperatures. On industrial scales, a high level of cleanliness of the base metal is required for brazing.
But these are merely small disadvantages when compared to the many advantages of the technique we discussed today in this article. If you’re still not convinced after reading, I want to challenge every reader to convince me that brazing is an inferior welding technique! Please, show me I’m wrong! I’d love my views to be challenged, but please argument your case well and convince me that other techniques are better. I’d love to hear your views in the comments below this article.
If you happen to be looking for some awesome welding gear, I also have a dedicated overview page for recommended gear right here. It’s where you will also find categories related to braze outfits and tools. So make sure to check out that overview page on your way out. Weld on!