The different types of welding joints

Welding joints are a crucial part of developing safe, secure structures. Welding joints are essential in creating a functional and durable product, and choosing the right type of welding joint for the job can make all the difference. The right welding joint not only improves the longevity of a structure but also improves the stress on a structure and load distribution.

In this blog, we’ll talk you through the main types of welding joints, the advantages and disadvantages of each and when to use them.

If you’re in need of professional welding services, our experts at Salamander Fabrication can craft high-quality, long-lasting projects. 

What Are Welding Joints?

A welding joint is the spot at which two pieces of metal are joined together when welded. There are a number of different types of welding joints, and the appropriate choice depends on a number of factors, including the thickness of the metal, accessibility, weight, etc. Choosing the right welding joint is crucial to ensure the stability and durability of your project and can help reduce the need for repairs in the long run. 

1. Butt Joint

A butt joint is one of the most common types of welding joints that is created by aligning two pieces of metal end to end and then welding along the joint. This welding style creates one continuous surface and allows for metals to be joined with and without any edge preparation.  

Butt joint welds are most commonly used in steel fabrication, in the fabrication of structures, such as bridges and parking garages, as well as piping systems. They are also used in the transportation industry for the manufacturing of car frames and exhaust systems.

Advantages

When the correct welding technique is used, a butt joint is a strong weld that proves highly durable for use across a range of materials. It also produces a smooth, cleaner joint, which means less prep and clean-up are required. 

Disadvantages

Whilst this is a reliable welding joint, it needs skilled application in order to be effective. The materials must be accurately aligned to create one even and equal surface. Poor penetration when welding can also make the joint insecure and cause it to weaken easily. 

2. Lap Joint

A lap joint gets its name from the process of welding overlapping edges of two pieces of metal. This process is commonly used when joining thin materials or materials of different thicknesses to ensure stability. 

This form of joint requires little edge preparation, making it a speedy and cost-effective option. This makes this welding joint type a popular choice for sheet metal fabrication and manufacturing production lines. 

Advantages

Overlapping sheets for metal is easy to assemble and doesn’t require as much precision as other techniques. The minimal joint prep also allows for faster work with results that create sturdy welds even on thin materials.  

Disadvantages

The main disadvantage for manufacturers is that overlapping metals for this technique uses more materials, but this is often offset by the speed and simplicity of the welding process, which allows for more daily production.

In some cases, corrosion can occur if moisture becomes trapped in the overlapping area, so extra attention is needed during the assembly process.

3. T-Joint 

A T-joint is exactly what it sounds like: the process of metal being welded together to form a T shape. One piece of metal is placed in the centre of a piece of flat metal and then welded on either side to create a solid structure. 

This joint is commonly used when creating structural supports like beams or steel frames.

Advantages

The T-joint is ideal for structures that can support heavy loads, making this type of welding joint popular in the construction industry. It can also be used on metals of large sizes, like beams and still create a sturdy joint. 

Disadvantages

The main issues that arise from this type of joint arise from the welding process. Skilled construction welders should carry out any welding on structural metals to avoid defects that can damage the integrity of a building or structure. The stress from any weight is also concentrated at the weld, so precision welding is essential.

4. Corner Joint

A corner joint is when two pieces of metal are joined at each corner to create a singular L-shaped structure. Commonly used for box or frame structures, corner joints are used to create two separate right-angle shapes and then welded together to create one single rectangular structure.

Corner joints can be welded on the inner or outer side of the structure or on both sides if the needs to be extra sturdy. Metal cabinets and industrial containers or agricultural enclosures commonly use corner joints.

Advantages

The biggest advantage of corner joint welding is the flexibility to weld both inner and outer corners. This can simplify the manufacturing process and also ensure a clean finish with hidden welding should inner corner joints be chosen. 

Disadvantages 

There is often extra preparation involved in corner joint welding, and there can often be edge prep needed for thicker materials. It may also take more time and precision to weld inner corners due to the difficult angle.  

5. Edge Joint

The final welding joint on our list is an edge joint, which is formed when metals are placed beside each other and then welded together along the same edge. This technique is usually only used for thinner materials or items that are for lighter duty. For this reason, edge joints are commonly used for decorative parts or seams of larger structures.

Advantages

Edge joints are fast and easy to create, and there’s little to no prep needed to join two materials together. This means that the production rate can be greatly increased compared to other processes that require more expert application, like T joints.

Disadvantages 

The downside to edge joints is that they can only be used for light loads and can’t be used for any structures due to the low strength of the weld. Whilst fine for decorative items or additional welding across products, edge joint welding should never be used as the base for any structure. 

How do you choose the right welding joint for your project?

To choose the right welding joint for your project, ensure you consider the following factors:

• Materials: Assess the materials you will use in your weld. This will indicate what strength of weld joint you need. For example, if you’re using thicker materials, you might need to use a butt joint as they have good mechanical strength.

• Welding process: You should also consider the welding process when you choose a weld joint. This is because some joints are more suitable for welding in certain positions than others.

• Accessibility: Evaluate what the process of your weld will entail before choosing your weld joint. For example, if you have poor weld area accessibility, it’s best to pick a weld joint that is easier to access, such as the butt joint.

Explore our full-service sheet metal fabrication

Here at Salamander, we’ve been part of a variety of different sheet metal fabrication projects. So when it comes to choosing the right materials, from the most suitable type of metal right down to the correct welding joint, we know exactly what will work best for your specific project.

Using our variety of sheet metal fabrication services, including welding and CAD design, as well as laser cutting, we’ll get to work on providing you with a high-quality, cost-effective result that exceeds your expectations.
For more information about our services here at Salamander Fabrications, speak to a member of our expert team today.