Advantages and disadvantages of welding as a joining method

Welding replaced mechanical fasteners as the joining method of choice in the 20th century. But as technology advances, companies are looking away from using welding as their primary joining method. You are reading this article because you want to know whether you should use welding, or look at other joining methods.

You’re in luck. As industrial adhesive manufacturers, we often come across instances where manufacturing companies are deciding whether to use welding or not. We know that there are certain advantages and disadvantages to welding.

This article will discuss both the advantages and disadvantages of welding. But just so you are aware, we will be discussing metal-to-metal joining in this article. Whilst you can weld plastic too, plastic welding is different and we would never recommend plastic welding where you require a strong joint.

By the end of this article, you will have a better understanding of metal-to-metal welding. You will become more informed about this joining method. We aim to help you make an informed decision about using welding for your application.

What are the advantages of welding?

Before we dive into the advantages of welding, we should clarify that we are comparing welding against other joining methods such as mechanical fasteners and structural adhesives. These are the two main alternatives to welding.

Now to find out why welding has been so popular over the years.

Welding creates a high-strength joint

Although some structural adhesives are fast catching up, no other joining method can achieve such high strength as welding. This is because the welder melts the two metal surfaces and interlinks the two substrates. 

Sometimes, the weld joint is so strong it becomes stronger than the metal itself. So if you want the highest-strength joint possible, welding is the joining method capable of achieving such high strengths.

Welding causes a high strength bond

Welding creates a permanent joint

Whilst having a reversible joint is sometimes beneficial, a permanent joint means the metals cannot be removed once joined. A permanent joint gives you the peace of mind that no one or nothing can tamper with your joint to cause it to come apart.

The only way the joint can come apart is if you designed the joint incorrectly, causing joint failure.

Welding doesn’t cause structural damage

With most types of mechanical fasteners, you will need to drill holes into the metal to secure them. These holes can cause structural damage and can even cause corrosion in the long term.

On the other hand, welding will not cause structural damage. You do not need to pre-drill holes into the metal. Therefore, welding does not increase the risk of metal corroding and will not weaken the metal.

Rivets can stretch the metal

What are the disadvantages of welding?

This section will discuss the disadvantages of welding as a joining method against mechanical fasteners and structural adhesives.

You will struggle to find qualified welders

Welding requires qualified workers. But there is a severe shortage of skilled welders at the moment. Coded welders are not only expensive, but they are hard to find too. 

Mechanical fasteners and structural adhesives do not require the same level of skilled labour. Unless you are Din 6701/2304 certified, then you may have to train the operative who is applying the adhesive. However, welding is the only joining method that requires highly-skilled labour.

Qualified welders are hard to find

Welded joints can’t withstand vibrations

Welded joints will not have much flexibility. So, if the joint is going to experience a lot of movement (like in a transportation/automotive application), you may experience joint failure. 

This is because metal isn’t a flexible material. When there are vibrations caused by the moving vehicle, the metal (and the weld) will not be able to absorb any of that movement. This means that the vibrations aren’t dampened.

On the other hand, structural adhesives can have high strength as well as flexibility. This means the adhesive absorbs any vibrations or impact rather than putting a strain on the metal. 

Mechanical fasteners will have the same problem as welding. They aren’t able to flex when experiencing movement. Sometimes, the stress can cause the mechanical fastener to ‘stretch’ the metal around the hole.

In summary, welding will not be able to absorb any vibrations or impact. It is not the ideal joining method where the joint will experience movement (or dynamic load).

Welding can distort the metal

The heating and cooling process from welding can cause the metal to distort. Whilst most experienced and coded welders should know how to avoid welding distortion, it is still a potential risk.

Welding distortion is a problem for two reasons:

  1. It can cause a weak joint
  2. It can affect the aesthetics

Welding is the only joining method that requires a severe amount of heat. Therefore, it is the only joining method that will cause the metal to distort in this manner.

Should you use welding for your application?

So now you know the advantages and disadvantages of welding, you want to know whether you should use welding or look at an alternative joining method.

As industrial adhesive manufacturers, we cannot answer that question for you. We would say that if you are able to find the labour and don’t have a joint that will experience a lot of movement, you should definitely explore welding further. 

However, if you don’t have the money or resource to find a highly skilled welder or you have a join that is going to experience movement, we would suggest looking at alternative joining methods.

As we have already mentioned, mechanical fasteners and structural adhesives are the two most common alternatives to welding.

Have a read of the article below to find out more about the alternatives to welding.

Want to learn more about the alternatives to welding? Find out here