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The Difference Between Soldering And Welding

Difference Between Soldering And Welding

The metal fabrication sector makes extensive use of both welding and soldering. Metal pieces are joined together by applying heat using both welding and soldering. Welding and soldering will be compared in this article by considering several variables, including metalling temperature, heat source, flux use, deformation, etc. However, it is helpful to understand the fundamentals of welding and soldering before discussing how they differ.

What is Welding?

Welding is a fabrication technique that involves applying high heat to melt the parts, allowing them to cool, and then fusing them to unite materials (metals or thermoplastics).

The two objects are fused during welding by applying heat and a filler substance. The filler material might pool between the bonded items when heated to a melting temperature. Weld, the end product, is a solid joint. Numerous welding procedures, such as gas welding, arc welding, resistance welding, forge welding, etc., are categorized according to the techniques used to join objects.

What is Soldering?

Soldering is a fabrication technique for fusing two objects by melting and injecting a filler substance into the joint. Compared to the base metal or adjacent metals, the filler used in soldering has a lower melting point. In contrast to welding, the base metal or workpiece is not melted during the soldering process.

Solder (filler metal) is melted during the soldering process using heat from a soldering iron. Around 316 °C is the temperature at which the solder is heated past its melting point, causing it to melt, and forming the soldering joint when it cools. Strong joints are primarily made on electrical and electronic circuit boards via soldering. Flux, a substance used in the soldering process, reinforces and enhances the joint's mechanical and electrical qualities.

Three main types of soldering can be made based on the temperature range:

  • Soft soldering (between 90 and 450 °C).
  • Hard (or silver) soldering at temperatures greater than 450 °C.
  • Brazing (over 450 °C).

Difference Between Soldering and Welding

The main distinctions between soldering and welding are outlined in the following table.

Factors That Differ




The method of combining materials—often metals or thermoplastics—is by melting the components under pressure, allowing them to cool, and then fusing them.

Soldering is a connecting technique that involves melting a filler substance (solder) to combine several types of metals.

Fusion Of Base Metal

The base metals are fused to form a joint during welding.

A filler substance creates the junction rather than the base metals fusing in soldering.


The ideal temperature for welding is much higher than 3800 °C. Typically, the base metal's melting point is above the welding temperature.

Below the melting point of the base metal, soldering is done at a very low temperature. Less than 400 °C is the normal soldering temperature.

The Joint's Strength

The welds are sturdy enough to support the weight. In most cases, the welding connection is stronger than the base metal.

Because soldering joints are less strong than welding joints, they cannot support the load.

Filler Material

The use of filler material is not required throughout the welding process. The type of welding determines whether fillers are required.

A filler substance (also known as solder) is necessary for soldering.

High-Temperature Effects

The joint, after welding, can tolerate high temperatures.

The soldered joint begins to degrade as the temperature rises since it cannot resist high temperatures.

Flux Is Needed

The use of flux is optional when welding.

It is necessary to use flux when soldering.

Heat Source

Heat is typically generated during welding via electric arcs, resistance, gas flames, plasma, laser beams, etc.

Soldering irons, electrical resistance, ovens, ultrasounds, and other heat sources are frequently used for soldering.

Workpiece Deformation

The workpiece deforms significantly when welding.

The possibility of base metal deformation during soldering is extremely low.


The welding process causes a significant amount of distortion to the piece.

The soldering process does not cause any distortion to the base metal.

Alteration To The Base Metal's Microstructure

The base metals' microstructure, or characteristics, has changed.

The basic metal's microstructure remains unchanged.

Fusing Of Different Metals

The joining of different metals is challenging in welding.

Soldering makes it simple to join metals that are not compatible.

Fusing Together Thin Sheets

The joining of thin metal sheets is particularly challenging due to the high temperatures used in the welding process.

Thin sheets can be quickly bonded with soldering.

Tensile Power

A welding joint has a tensile strength of more than 200 mega Pascals.

A soldering joint has a tensile strength of under 75 mega Pascals.

Workpiece Heating And Melting.

In the welding process, the base metals or workpieces are heated and melted.

Melting and heating of workpieces or base metals are not necessary for soldering.

Heat Treatment Is Required

Heat treatments are always necessary for welding.

In soldering, heat treatments are never necessary.


The workpieces don't need to be heated before welding.

Preheating the workpiece before soldering is not required, however, it may result in a high-quality bond.

Need A Qualified Operator

It requires specialized skills to weld.

Soldering does not require any specialized expertise.

Power Use

Welding uses more energy.

Low power consumption is used in soldering


Most mechanical industries, including those that make cars, airplanes, and ships, require welding.

For designing circuit boards and other purposes, soldering is mostly employed in the electrical and electronic sectors.


In this post, we've outlined a few key differences between welding and soldering that are sufficient to show their usefulness for various purposes. Both soldering and welding are techniques for joining metallic components. The primary difference between welding and soldering is the melting of the base metal, which is not the case with soldering.
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