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Lets Nail 5 Welding Joints With Ease

New to welding? Let’s talk about the most common ways you can join those pieces of metal back together using welding joints.

Welding is an art in itself. You need a steady hand, patience and the knowledge of the best technique and practice to use to receive the best possible outcome. Every job is different, therefore every job requires a different joint and approach.

A “Weld Joint” is essentially how you are connecting the pieces of metal together or how they are aligned with each other. Each joint has a specific purpose and design which affects the quality and cost of the welding project. This is why you should focus and learn about each of the welding joints we will talk about so you can have the skill to select the most appropriate welding joints for your projects. So let’s get started!

There are five basic welding joints commonly used in the industry, according to the AWS. These are:

Welding joints
Image sourced from https://weldingpros.net/

These 5 welding joints basically resemble what their names say. So let’s look into these welding joints in more depth.

Butt Welding Joints

A butt joint, also called a butt weld, is a joint where you place two pieces of metal together on the same plane and they are joined side by side by a weld. A butt weld is the most common of the welding joints you will find used in the fabrication of structures and pipe systems. You can perform the butt joint in many different variations to achieve the desired result. Each variation serves a different purpose, each with varying factors such as the shape of the groove, and the layering and width of the gap.

Butt Welding Joints Examples

Below are some typical examples of butt joints:

  • Square
  • Single or double bevel
  • Single or double J
  • Single or double V
  • Single or double U

The surface of the metal that gets melted during welding is called the “faying” surface. These surfaces can be shaped before welding to increase strength in the weld, this is called edge preparation.

Other reasons for edge preparation include:

  • Deeper weld penetration
  • Smoother appearance
  • Increased strength
  • Certain codes and standards to meet
  • Type of metal being used

The thicker the metal you are dealing with, the weld joint design used will change to ensure a secure and sound weld. For example, a square butt joint could make full penetration welds on thin sections and materials, but it wouldn’t be the best choice on thicker sections as you risk the strength and soundness of the weld.

When it comes to butt welding joints, common defects may include burn-through, porosity, cracking or incomplete penetration. However, these can be avoided by modifying the welding variables.

Tee Welding Joints

As the name says, tee welding joints are formed when two pieces intersect at a 90° angle, resulting in a ‘T’ shape. A tee joint can also be performed when a tube or pipe needs to be welding onto a base plate. When using tee welding joints, it’s important you have provided effective penetration into the roof of the weld.

Tee Welding Joints Examples

A tee joint can be performed in a variety of styles such as:

  • Plug weld
  • Slot weld
  • Bevel-groove weld
  • Fillet weld
  • J-groove weld
  • Flare-bevel-groove weld

A groove is not typically needed when using a tee joint, unless the base metal is thick or when the welding on both sides cannot support the load the joint is undertaking. A common defect that occurs with tee welding joints is lamellar tearing, due to restriction experienced by the joint. To prevent this, welders will often place a stopper to prevent joint deformities. 

Corner Welding Joints

Corner welding joints are kind of similar to a tee joint, but as the name suggests, the joins are met in a corner, rather than in the middle like a tee joint. Corner joints can be performed in an open or closed form.

Corner joints are very commonly used with sheet metal work, for construction of frames, boxes, and other shapes. An outer corner joint can be done up in two different ways; to form a V-groove (A), or to form a square butt joint (B).

Corner Joint comparison types
Corner Welding Joints Examples

Commonly used examples for corner welding joints are:

  • Square groove
  • Fillet weld
  • J groove weld
  • V groove weld
  • Spot weld
  • Edge weld
  • Corner flanging edges
  • Flare V groove weld

Lap Welding Joints

A lap joint is formed when two pieces of metal are placed in an overlapping pattern on top of each other. So basically a step up from the butt joints! A lap joint is great for connecting two pieces with different material thickness. Your welds can be placed on one or both sides depending on the function the joint needs to have.

A lap joint is also very commonly used in sheet metal work, but rarely used with thicker materials due to the potential of lamellar tearing or corrosion in the overlapping of materials.

Lap Welding Joints Examples

The common welds used with lap joints are:

  • Fillet weld
  • J groove weld
  • Bevel groove weld
  • Plug weld
  • Slot weld
  • Spot weld

Edge Welding Joints

Finally, we have our edge joint. An edge joint is formed by the metal surfaces being placed together so that the edges are even. The edge joint can have one or both the plates bent at an angle. The purpose of an edge weld joint is to join parts together to allow the internal stresses over the joint to be distributed.

Edge welding joints are commonly used with flanged edges with sheet metal work or when adjacent pieces must be attached.

When working with edge joints it is important to note that everything will influence the final weld. As the metal is usually thin and if the finished weld requires a high quality finish, then the filler metal, welding process, joint design, penetration, rate of travel, deposition rate, heat input and rate of cooling all need to be highly considered.

Edge Welding Joints Examples

The common weld types with edge joints are:

  • Edge welding joint
  • Bevel groove weld
  • V groove weld
  • J groove weld
  • U groove weld
  • Corner flange
  • Edge flange

Due to overlapping parts, this type of joint is more prone to corrosion. Welders must keep in mind other defects like slag inclusion, lack of fusion and porosity, which can also occur.

Conclusion And Summary of Welding Joints

Hopefully after reading a basic overview on the different welding joints, you can better understand why the need for all the different types and in what circumstances your would use them. As I said at the beginning, welding is an art and every job is different, therefore every job requires a different joint and approach. Welders today are expected to understand the types of force being applied to each component and need to determine the best joint design to prevent the forces causing a structural failure. An improper choice or configuration of a weld joint can cause weld and material defects, such as cracking or lamination, therefore, skilled welders must know how to adjust variables to avoid these defects. 

If you want to look into becoming a professional welder, take a look at this program with the Universal Technical Institute that can provide you with the training you need to get there in just 36 weeks. Learning to work with different welding joints and types can take lots of practice. Even in some cases, requires the completion of a formal training program, such as the Welding Technology training program offered at Universal Technical Institute (UTI).

So slowly start learning today to perform the different welds, and before you know it, you’ll be on the road to welding greatness!

Want to learn about something else!? Take a look at out other Quick Guides to plasma cutting and welding.

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