Difference Between Soldering and Welding: Full Notch Comparisons

Fabrication procedures are relatively standard, but very few know about the difference between soldering and welding. Although both of them are similar in application, their procedures are slightly different. Comparatively, welding joints are stronger than the soldering ones.

It is necessary to have some basic knowledge about the procedures before doing it alone. Soldering uses the technique of melting of the soldering rod, while welding focuses on the heating of the metals or materials to join.

The former uses a filler, which is mandatory, while the latter may or may not use an additional material. Both soldering and welding have their applications in many industries. The procedure of welding is complex than soldering and thus requires professional or previous experience in the field. 

Below is a detailed description of the procedure of soldering and welding. For better understanding, along with the differences, we have also mentioned the types that each of the procedures has. 

Difference Between Soldering and Welding: Face to Face Comparisons

What is Soldering?

Although a joining process of any metallic items, it uses another material within a melting point of 450C. To understand the process, below mentioned points would be helpful:

  • During the soldering procedure, the actual material does not melt
  • Requires a proper arrangement of the joining materials, say in an even surface
  • The state of the additional material in the process is in liquid form
  • On cooling, the additional material hardens and results in a joined state of the base material
  • Both the materials used in the process result from metallurgy and reacts to hardens by forming intermetallic components

While soldering a metallic alloy, say tin and lead, a hot iron is used as additional material for the process. As the iron cools, it binds the alloy together with an electrical association.

Types of Soldering

Soldering techniques are of different types depending on the temperature used for the additional material. As the temperature increases, the soldering results achieve their different forms. Based on this, the strength of soldering is of the following types:

Soft Soldering Technique

Here, the melting point of additional material is the lowest. Besides, the temperature ranges from 90 C to 450 C, and thus the thermal stress is quite less. As a result, the joints are not strong enough to hold mechanical usages. 

Hard Soldering Technique

Silver soldering is the process where silver is the additional metal. Although the process is similar to soft soldering but requires a temperature of more than 450 C. Further, it uses a blowtorch to achieve this higher temperature.

However, it is crucial to ensure that there is no reaction with oxygen, or else it will result in combustion during the process. 

Brazing

Similar to the process of hard soldering, but the difference lies in the melting point. Instead of melting, the metal is allowed to heat up. As both the materials heat up sufficiently, the additional metal binds both of them together.

Here, joining two or metals is possible, but the additional or filler metal must have a lower melting point than the base metals. 

What is Welding?

For manufacturing electrical items, it is essential to join one or more metals together through the process of fabrication. However, in order to ensure that the two parts join each other securely, a different technique is applicable.

This is known as welding, wherewith the support of heat, two parts fuse. But the process completes once the fused area cools down. These parts are usually of metals or thermoplastic. For more details, look into the following points:

  • The joining parts are called the base or parent metals
  • The fusion requires an additional or filler metal
  • In some cases, fillers are not required, as well
  • Weldment requires certain environmental conditions based on the type of materials
  • These conditions can be either heating or pressing. Some also use electricity, gas, etc

Types of Welding

As per the difference in conditions, welding techniques are of various types. Let us discuss each of them in brief. 

Arc Welding

In this process, the metals fuse with the help of an electric arc, which provides heat from the electric power. As the power heats up the metal surface, the metals fuse together. For preventing combustion, a gas is used as a shield so that the metals do not cause combustion. 

Friction Welding

Here, the metals fuse through friction between them and do not require melting. With the induction of friction in metals, they fuse from the heat generated and do not require any additional filler. As the materials soften, they join and create a bond. 

Electron Welding

When a beam of electrons hits the metal surface at high speed, it changes into heat. This heat fuses the metal parts together in the process. However, it is necessary to avoid any kind of air in the vicinity. Thus, a vacuum is a necessity here to prevent the electrons lose their direction. 

Laser Welding

Often used to join thermoplastics like polyethylene, polyvinyl chloride, polyesters, etc. Here the pieces connect each other when a strong laser hits them. On contacting the surface, they tend to generate heat, which causes the fusion.

Laser welding is easier and faster than others and thus is useful in industrial usage. 

Resistance Welding

For joining two pieces together, two electrodes or rotating wheels generate the heat. It is mostly used in vehicle manufacturing industries. 

Difference Between Soldering and Welding: By Features

Many people use the term soldering and welding interchangeably. However, there are quite a few differences between soldering and welding. Some of them are as follows:

Strength

Both of them are joining techniques and require a good amount of time and effort. However, welding joints are much stronger in terms of its fusion and durability of the joined parts. Perfectly welded materials are as strong as both the base materials.

In contrast, the soldered joints are not strong enough. It is because there is no mechanical bond between the base materials and the filler.

Temperature

Soldering requires around 450 C to continue the process whereas; welding requires more than 450 C. Soldering thus, requires comparatively less temperature than welding. 

Additional Material

In the soldering procedure, the additional material must join the other two parts. But in welding, it is not mandatory to use an additional material. Welding only requires the source of heat, which melts the parts and fuses them.

But in soldering, the additional filler is an important bond that adjoins the other two materials together. 

Heat Requirement

Welding requires heating of the joining materials, but soldering does not require heating. Welding two metals or thermoplastic is possible only when there is some amount of heat.

However, this heat can be from different sources like a laser, electrons, friction, etc. Soldering is the process where the filler melts and joins the base material.

Change in Properties

Soldering only joins the metals with each other and does not change their properties. But, during welding, there are certain changes in the mechanical properties of the joining metal.  

Combustion

During welding, there are chances that the base materials may cause combustion due to their contact with air. One of the essential precautions necessary for welding is the prevention of any chemical process with oxygen. In contrast, no such precautionary measures are necessary during soldering. 

Wetting

Soldering requires flux to protect the base material, but in welding, its usage is not necessary. However, some people consider using it just as a precaution so that there is no harm on the base material’s surface. 

Heat Source

A soldering iron is sufficient to fuse two metals in soldering. But in welding, heat generation can be through various other options, including resistance, friction, gas, laser, etc. 

Change of Shape

Due to an increased heating and high heat source in welding, there are chances of a change in shape in the base materials in both welding and soldering. But the degree of deformation is higher in soldering than in welding. 

Fillers

In soldering, the requirement of fillers is a must. But in welding, it is optional. Usually, welding occurs through the generation of heat from an external source. The heat produced by this source enhances the base materials to join together. 

Cooling

The cooling of soldering material is faster than the welding ones. Welding guns take time to cool as they use a high amount of heat during the process. Some of them cool either through an external air source, while others require a water cooling process.

Soldering irons cools down quite fast and is ready to use in the next spot within no time. 

Types

Soldering includes either hard or soft soldering. Brazing is a type of soldering technique where the base material heats up instead of melting. Welding, on the other hand, can be of various types.

They are ranging from gas or arc welding, friction, electron, laser, and resistance. Welding uses any source of heat from an external source to fuse the metals. 

Process

Using a soldering rod to fuse different types of metals, the process is known as soldering. As the solder melts, the metals join together with the strong electrical bond. Welding, on the other hand, melts the base metal instead of the additional one.

On cooling, the weldment is stronger than the base material. Here the base materials are usually the same. For example, it isn’t easy to weld copper with steel. 

Vacuum

Welding by electrons requires a space where there is no oxygen, and thus, a vacuum is necessary. But there is no such requirement while soldering. 

Speed of Heat

There is no exact consistency of heat required in soldering. However, in electron welding, the electrons’ speed must be high, which will result in the generation of heat on hitting the metal surface. 

Applications

Soldering is for joining metallic pieces together and thus has a wider application. Its mechanism is useful in electronics, air conditioners, plumbing, TV, radio, etc. Further, it is useful in joining wires and cables to power outlets. 

Welding, on the other hand, has its applications based on its types. Such as:

  • Arc welding is useful in manufacturing industries, shipbuilding, railroads, and other repairing sectors
  • Friction welding finds its uses in those producing rollers, tubes, shafts, and similar other products. These are usually found in oil fields, aeronautics, etc
  • Electron welding applications are in defense, medical, nuclear plans, oil fields, and aircraft manufacturers
  • Laser welding is useful while joining parts of automobiles
  • Industries that manufacture nuts, bolts, tanks, boilers, etc., use resistance welding techniques

Installation Skills

Soldering is not a complex technique, but the user must know the specifications of using a soldering rod. Basic knowledge of using skills is sufficient for soldering. On the other hand, welding is a complex procedure and requires professionals or experienced workers to perform it. 

Conclusion

As we approach the end of the article, we hope you are well-enlightened about the difference between soldering and welding. People often tend to confuse between the two or use it as a similar term. But the difference in their procedure makes them widely used all over the world.

Almost all major industry sectors engage in welding procedures, especially those involved in automobiles or automotive industries. Soldering is used mostly in electronic products where there is often the requirement to join wires and cables.

The soldering process uses a soldering rod, which, when it melts, joins the base metals together. Welding, in contrast, heats the metals and utilizes this heat to fuse the metals. If you are involved in either of the techniques, ensure using protective gear to prevent hazardous accidents. 

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