Soldering and welding - the differences

Especially in the advanced way of metalworking soldering and welding often look very similar. Where exactly the difference between the two connection techniques lies and what differences in the durability of the connection exist, you will learn in detail in this post.

Similarities between soldering and welding

Both brazing and welding are used to join metals together. When soldering, it refers to the so-called "brazing". Brazing always takes place in a temperature range of at least 450° C, usually higher, whereas soft soldering takes place in temperature ranges of around 180° C to 250° C.

In both cases, a so-called "cohesive" compound is formed, which is also conductive. The two materials are firmly connected. The great similarity of both methods can be seen for example in so-called flame soldering.


Additional material and temperature range


During welding, both workpiece ends are heated to the point where they begin to melt. The so-called "solidus temperature" (temperature below which a metallic structure is firm and stable) is exceeded.

An additional melting material (the so-called welding wire or welding electrode) is added additionally to improve the connection (not to them at all) make!)


When brazing, however, the solder makes the actual connection. The workpieces are not heated so much that the solidus temperature is exceeded, but only so far that the solder used liquefies.

For every metal and every alloy you have to use suitable solders and fluxes (see brass for example).

When soldering so the solder represents the bridge between the two pieces of metal, while welding the metal is directly connected.


You can only weld the same materials together. If you want to combine different metals, you always have to solder. Since the solder makes the bridge between the two metals, soldering can also be used for alloys that are different (however, both parts must be metals).

Differences in durability

Welds can cause problems because of the high temperatures - such as distortions or distortions. Also, the local hardness of the metal can be changed by a transformation of the structure at the weld. This is especially true for workpieces of small thickness.

Brazing produces a very stable bond, which in many cases can compete with welds in terms of durability if it is done properly (especially in gap brazing). In the industrial sector, soldering is often cheaper and much less expensive than welding.

Tips & Tricks

While they need some experience for brazing, if you have a little practice this is certainly easier and less expensive than welding.