Welding vs. Soldering – What are the Differences?


In Brief: Welding vs. Soldering

The primary difference between Soldering and welding is the use of filler metal. Soldering uses a filler wire or flux for the joining of the two jobs whereas the welding process includes the melting of the two jobs to creating a joint. Welding finds its applications in industrial processes, automotive, equipment construction, etc. whereas soldering is used in electrical contacts, plumbing or metalwork at low temperatures.

Soldering and welding are two joining processes used to adequately append metal together, processes which use adhesives, screws nails and other means as such are often not suited for metal works.

The processes are used for various purposes in a number of industries. The processes do have some commonality but differ in basic functioning.

Jobs have to be prepared beforehand regardless of the process used for joining metals.

The most important aspect of preparation is cleaning the joint area.

If not cleaned properly the joints can be subject to a structural defect.

Another important parameter would be heated, the metals in both cases should be heated to proper temperatures to form a strong joint.

Overview of Welding

Welding is the process of joining two or more metals through melting metals present in the joint in an effort to make the two pieces work as one object.

In the process of welding, an arc is created by the use of a power supply or a gas.

The arc is then used to created high amounts of heat which melts the metals in the area of the joint. When the joint cools down, a joint is formed.

A point to note is that the two metals to be welded need to be similar in characteristics, specifically melting points.

Welding is used in a variety of applications from domestic to industrial uses.

Welder processes are often cheaper and can be used for a number of purposes with a single machine, this brings value to the process and the machine.

The welding process can be used for virtually all metals like stainless steel, mild steel, aluminum, and metal alloys.

There are a number of types of welding processes such as TIG welding, MIG welding, stick welding, or arc welding.

All of these processes are differentiated on the basis of applications. All the processes are still based on the same theory but differ in practical implementation.

The welding processes can also be categorized on the basis of sources used, the welding processes can be segregated as gas welding and arc welding.

There is certain equipment that is required for welding, these often differ based on that type of welding the user wants to do.

Starting with gas welding, this type of welding uses fuel to create heat and high temperatures to melt the metals.

The apparatus for gas welding includes a fuel gas cylinder, oxygen cylinder, and a welding torch.

The other type of welding is arc welding which uses electricity to raise temperatures and create ample heat.

The usual apparatus for this type of welding includes a MIG or TIG or Plasma welding gun, an electric power source, optional filler wire.


  • Stronger joints in comparison
  • Variety in applications
  • Cost-effective
  • Can be used for high temperatures
  • Easier to clean up post-process


  • Not suitable for thinner metals
  • Demands skill

Welding is often used for relatively thicker materials due to their capacity of producing higher amounts of heat.

Welding is roughly done at about 6000 to 8000 degrees Fahrenheit.

With all this capacity of the welding process, the welding process does require some skill to perform.

Appropriate welding gear is also necessary as welding can be dangerous if not done correctly.

Overview of Soldering

The process of soldering involves the joining of two metals by applying solder to the joint or metal sections.

A soldering iron is used to melt the solder, which is a filler metal, at low temperatures of up to 850 degrees Fahrenheit.

The solder in a job is placed exactly where the materials are to be joined. Solder can be solid in the form of a wire or also be utilized in a paste form, called a flux, to be precise.

The process of soldering requires a soldering iron and a solder material or a flux.

Some filler metals that are mostly used for the soldering process include combinations of aluminum, copper, lead, silver, tin and zinc alloys.

Soldering has two main types named as iron soldering and wave soldering. Iron soldering is one of the oldest and the easiest joining processes.

It involves a soldering iron with a copper tip, this tip stores and transfers heat to the joint which in turn forms the solder.

The process of wave soldering is most commonly used in joints of electronic components and circuit board manufacturing.

Continuous circulation of solder waves is put into contact with the joint to form the solder.

The process of wave soldering can be performed very quickly and can often be automated in a wave machine that can include the processes of creating flux, preheating, soldering and removing flux residue on a conveyor that keeps the process going continuously.


  • Involves low temperature and heat
  • Dissimilar materials can be welded
  • Thinner metals can be welded effectively
  • Requires less skill
  • Faster to perform


  • It cannot be used to struggle large sections.
  • Joint strength is low in comparison

Soldering’s most common use is to join electrical contacts.

It is also used in plumbing and metalwork requiring low temperatures.

It is useful for various metals, including gold, silver, copper, brass, and iron.

The soldering process involves the preparation of the metal, heating the metal ends, melting solder in the joint area, cleaning the metal and cooling the metal.

Key Differences between Welding & Soldering

There are a few glaring differences between the two processes of soldering and welding that a user should know so as to apply the correct technique to the job.

In welding, the metal workpieces and the metal base are heated and subsequently melted, whereas in soldering the only requirement is to weld the solder or the filler metal, no heating of the workpieces takes place.

The temperature ranges in the processes are also substantially different.

Where welding processes require up to 6,500 degrees Fahrenheit to melt the metals, the soldering process requires about 840 degrees Fahrenheit to melt the filler metal.

Mechanical properties of base metals are very likely to be subjected to a change in the area of the joint, largely due to the heating and cooling of the metals during a weld.

In soldering, mechanical properties don’t change at all.

The process of welding requires more skill as compared to soldering, this is due to the high temperatures involved and multiple parameters that the user has to set prior to the process.


Both processes of joining are the most commonly used forms of joining metal. However, soldering and welding have different applications.

The first basic difference in the functioning of the processes is that in the process of soldering only the solder is heated, not the workpieces themselves like welding.

The process of welding has a characteristic high temperature which enables it to weld thicker materials as compared to the process of soldering which is more effective in welding thinner materials.

The properties of a metal can also be changed during the process due to the high amounts of heat involved in the welding process.

The factors like the type materials are its metal or non-metal, the purpose of the joint, and the size of the structure all are crucial to the selection of the process that is the best to use.

The key differences lie in the heat used, skill requirements and compatible metals, all of which play a role in deciding where to use the processes.

About Joyce Brown

Joyce writes on how things work and product reviews, especially related to solar energy. She holds a degree in renewable energy and is passionate about making the world a better place. She is a hardcore vegan and loves to cook.