Brazing vs Welding: What’s the difference?

There are two main ways to join metals – brazing and welding. These words, however, are often naively interchanged, which can be confusing. Whilst both join metals, there are some fundamental differences between the two.

As one of the UK’s leading suppliers of aluminium and steel, we believe we're best placed to explain how brazing and welding work, and the differences between them. Read on to learn more!

Get in touch to order your metal online today

Brazing: What is it and how does it work?

Let’s start with brazing.

What is brazing?

Brazing is a metal joining process where two or more metals are joined together by melting and flowing a filler metal into the joint. The filler metal will have a lower melting point than the adjoining metal.

How does brazing work?

The brazing process works where the filler metal flows into the joint between the close-fitting parts by capillary action – the ability of a liquid to flow in narrow spaces without the support of or in opposition to external forces like gravity.

The filler metal is then heated to slightly above its melting point while protected by a flux (a chemical cleaning and purifying agent). This can then flow over the base metal, which is then cooled to join the workpieces together.

Welding: What is it and how does it work?

So, how does welding differ to brazing?

What is welding?

Welding is a fabrication process whereby two or more metals are fused together through heat and/or pressure, with the joining occurring as the parts cool.

How does welding work?

Welding works through fusion – the term for joining metals with similar melting points. Due to their high melting points, a weld pool (a pool of molten metal) is formed. This pool cools to form a joint that’s stronger than the base metal, and the heat pressure can assist the welding.

Welding also requires a shield protecting the filler metal from being contaminated or oxidised, as this would cause iron oxide and will rust the metal.

The differences between brazing and welding

The heat source

Brazing works by using a torch, furnace, dipped or resistance as heat sources, with temperatures clearing 450°C.

Welding, on the other hand, uses electricity as the heat source, with temperatures reaching in excess of 5,500°C.

Melting point temperature of the filler metal

For brazing, the filler metal used to join the metals together has a lower melting point than the adjoining metal. For welding, the filler metal has a higher melting point.

Brazing uses capillary action whereas welding uses fusion

Because of the different melting points, brazing depends on capillary action – how the alloys of the melted filler metal are able to flow between the two metal parts.

Welding uses fusion – how all the metals are heated to melting point so that they can be joined together.

Use of fabricators

With brazing, the fabricator (i.e. the individual responsible for joining the metal) would not melt the base metal in brazing.

By contrast, fabricators melt the base metal and each workpiece together when welding.

Types of brazing and welding techniques

There are a number of techniques for brazing and welding, and these can be broken down into the following sub-techniques.

Brazing sub-techniques

Types of brazing techniques include:

• Vacuum brazing
• Silver brazing
• Furnace brazing
• Torch brazing
• Dip brazing

Welding sub-techniques

There are a number of welding sub-techniques, such as:

• Glass welding
• Electric resistance welding
• Electroslag welding
• Shielded metal arc welding
• Submerged arc welding
• Flux-cored arc welding
• Gas metal arc welding
• Gas tungsten arc welding
• Oxy-fuel welding
• Plastic welding

Clickmetal is specialists in the online supply of stainless steel and aluminium

Clickmetal specialise in the online supply of aluminium and other nonferrous metals. We trim down all metal to your required size and deliver across the United Kingdom to both the trade and domestic customers.

Choose from our huge range of aluminium, stainless steel, mild steel, and galvanised steel. Order online today for bespoke sizing and quick, nationwide delivery.

To learn more about how we can supply the metal for your next brazing or welding project, contact us today by calling our friendly team on 01794 526090.