The Difference Between Soldering, Brazing and Welding

September 28, 2018

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To the average person the terms soldering, brazing, and welding, which describe the process of joining of two or more metals, may appear synonymous. We're here to tell you that there are differences between these processes...

1. Temperature Range

The main difference being the temperature! You see when we talk about soldering it can refer to both hard and soft soldering. Solder alloys with melting temperatures below 840°F are considered to be soft and any soldering done above 840°F is referred to as brazing or “hard soldering”; also called silver soldering when a silver alloy is used. As for welding the process occurs much higher up on the scale at 6000°C and up.

2. Equipment Used

The second difference is the tool being used. Due to the high temperatures required for brazing, a torch or furnace is needed. Soft soldering can be done with a regular soldering iron or heat gun, as you would in electronics work. Many production lines will also use wave solder baths or special ovens for their electronics soldering. Welding, on the other hand, is commonly performed with a MIG, TIG or ARC welder.

3. Joining Process

The final difference is the process by which the metals are joined. For soft and hard soldering the process will be the same; the solder has a lower melting point than the metal it is being applied to. The solder simply melts and bonds to the work pieces in a process called wetting. In welding however the actual work pieces are melted together and a filler metal is added to form a weld pool. This process joins the metals through fusion and the joint formed becomes stronger than the original base material.

Now let's take a closer look at these three metal joining processes individually.

Soldering

Soldering or soft soldering is the least invasive method of metal joining. It occurs at relatively low temperatures compared to brazing and welding. All electronics work falls under this category.

Melting temperatures below 450°C / 840°F

Uses a soldering iron, hot air gun, desoldering gun, or preheater

Reversible through desoldering

Brazing

Brazing or hard soldering uses higher temperature solder alloys that require a torch to melt them. This is for more industrial applications including plumbing, jewelry, and dentistry.

Melting temperatures above 450°C / 840°F

Uses a butane or acelytlene torch to melt solder

Reversible but not as easily as soft soldering joints.

Welding

Welding is a fundamentally different process than soldering or brazing because the workpiece itself is being melted and fused together with the parts. It is not reversible like the other two methods.

Melting temperatures around 5500°C / 10,000°F

Uses a MIG, TIG, or ARC welder.

Irreversible process where workpieces are fused together.

Quick Review

Remember that temperature range is the determining factor between soldering, brazing, and welding. If you are unsure which method to use just look at what temp is required for the job.

Second, the melting range of the solder depends on the type of alloy used. Different mixtures of metals will have different melting points and therefore different heat requirements.

Finally, the higher the melting point of the alloy, the stronger the joint will usually be!

Well that’s it and if you have any questions or comments please leave them below and be sure to check out our YouTube channel for more soldering tips and tricks!

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