types of welding joints

5 Types of Welding Joints

Welding is a craft that can be pretty challenging to grasp fully. It requires a lot of training, patience, and creativity. To get the job done in the right and best way possible, a welder needs to have a deep knowledge of the various styles and techniques used in this profession. Knowing the different types of welding joints is also a vital part of the training process. 

The AWS (American Welding Society) describes a welding joint as the way or manner workpieces are being fused. There are numerous welding applications, and all these applications require varying welding types, positions, and joints to achieve the best result. 

The joint welding design also determines the quality level and cost of welding two workpieces. Choosing the best joint design for a job needs a high-level skill and focus. 

The five basic types of welding joints in the welding industry, acknowledged by the American Welding Society, are; Tee joint, Lap joint, Corner joint, Edge joint, and Butt joint. These types of joints are used in different welding applications and for other welding processes so the welder can deliver high-quality welds. 

Without the proper guide, understanding the concept behind ‘welding joints’ and their applications can be tricky. Not too worry! This should help you out to a large extent. 

Tee Joint 

Tee joints are made when two workpieces meet at 90-degree. A piece’s edge is joined together with the other piece’s center, forming the T – shape. This type of joint is considered a form of a fillet weld, and it can be designed also when a welder welds a pipe onto a plate. Considering this joint type, the welder must ascertain that there is deep penetration into the weld roof. 

There are several welding methods a welder can adopt to design a Tee joint. It includes the fillet weld, melts through the weld, plug weld, bevel-groove weld, J-groove weld, and slot weld. 

Tee-joints are not commonly designed with grooves. Except when the piece is very thick, and the welding on the sides cannot hold the load the joint has to withstand. 

Lamellar tearing is a common defect that usually occurs with Tee joints, and this is due to joint restriction. The welder will have to place a stopper to avoid any deformity of the joint. 

Lap Joint 

Lap joints are refined versions of a butt joint. A welder can get a lap joint by placing two metal pieces on top of each other in an overlapping position. These joints are primarily used when two materials of different thickness levels are to be fused. Welding can be done on both sides or just one side. 

A lap joint is not often used on thick materials but is used a lot on sheet metals. Likely hiccups when using this type of weld joint include Lamellar tearing, just like in Tee joints, and corrosion due to the overlapping work-pieces. 

Like the other joints, these hiccups can also be averted. The welder can modify variables and use the proper welding technique. 

Corner Joint 

This joint is quite similar to the Tee joint. The significant difference is the positioning of the metal. In designing a Tee joint, the metal is placed at the center of the piece. For a corner joint design, the metal meets at the edge or corner in a closed or open manner, thereby forming the L-shape. 

These joints are broadly utilized in the sheet-metal industry to construct boxes, frames, and so many other applications. Two ways are used to fit up the outside of a corner joint. It can take either firm a V-groove or a square-butt groove. 

The ways to form a corner joint are J-groove, spot edge, V-groove, square or butt groove, corner flange, J-groove, and fillet. 

Edge Jointing 

For a welder to get an edge joint, the two workpieces will be placed together to ensure equal edges. The two pieces or one of the pieces can be formed by bending them at the desired angle. 

A weld joint’s primary purpose is to join pieces together so the stresses can be evenly distributed. The causes of stress in joints are compression, tensile, bending, shear, and torsion. The welded joint’s ability to withstand these stresses is dependent on the joint’s design and the integrity of the weld. Some joints are capable of withstanding specific forces more than others. 

The kind of welding process utilized has a significant role in selecting the right weld joint for the job. The welding process used affects the quality of the weld on some joints. Rate of deposition, travel rate, and penetration are also part of the affecting factors. 

Edge flange, corner flange, V-groove, Bevel groove, J-groove, and square groove are the various styles applicable for getting an edge joint. 

Because the pieces overlap, it makes them susceptible to corrosion. Porosity, slag, and no fusion are other defects that can occur. 

Butt Joint 

The butt joint is a welding joint best described as when two workpieces of similar metal are joined in one plane, and each of the sides of the metal is welded together. This type of joint is commonly used during the building of structures and in pipeline construction. It is an easy joint to pull off, as there are many different ways a welder can employ to get a good outcome. 

Butt welds are achieved through several means, and the various welding process has individual design purposes. This means every butt weld is designed for a specific purpose. The distinguishing factor between the various forms of butt welds is the layering, groove shape, and gap width. 

Typical forms of some of these butt weld joints are; double V, double bevel, single U, single J, single V, square, double U grooves, and single bevel. 

The welding area or the metal surface is referred to as the faying surface, and the welder can shape this surface into any form before carrying out the welding procedure to get a higher weld strength. This is termed ‘Edge preparation.’ On both Butt joint members, the edge preparation can be the same or shaped differently on each side. 

A welder needs to set the faying surface due to these reasons; higher strength, deeper welding penetration, standards, metal, and smooth finishing. 

For some instances, the actual angle, shape, and size can be given for a groove. If the welder doesn’t know the correct dimensions, the groove can be designed to an appropriate size. However, you should know that a wild groove will require more welding to complete. 

Also, as the workpiece becomes tougher, you have to change the joint’s design to get a quality weld. On light materials, it is easy to make a deep penetration with a square-butt joint. While it is almost impossible to make deep penetration without using some grooves when welding thick materials. 

When speaking of the Butt joint, common defects are associated with this joint; porosity, burn-through, or cracking. However, these defects can be eliminated when the welder modifies the welding variables. 

Relevance of these Welding Joints

Grasping the technicalities involved in joint design is crucial for welders. This knowledge enables you to recognize the forces to be applied to the piece. 

Modern welders must know the forces being exerted on the weldment and determine the correct weld joint for the piece to handle the pressures to prevent failure of the material. Implementing the wrong joint for a workpiece can cause some defects, including cracking. To avoid these defects, you have to be skilled. 

To critically learn the various welding techniques and comfortably work with the different welding joints, you should complete a formal training program in the welding field. As a certified welder, you won’t only be trained on how to work with the types of welding joints; you will also get to know the safety rules to the complex processes of welding. 

FAQs

What are the 3 types of fillet joint? 

3 types of fillet joints are the corner joint, Tee joint, and Lap joint. The Tee joint is an excellent example of the staggered intermittent fillet weld, a joint between two lines. 

How many types of welds are there? 

There are four main types of welds which include the gas tungsten arc, also known as (GTAW/TIG) welding, the gas metal arc (GMAW/MIG) welding, flux-cored arc (FCAW) welding, and the shielded metal arc or SMAW welding. 

What are the five types of welding? 

MIG welding is a straightforward type of welding and is more suitable for beginners. It consists of two kinds; the flux core and bare wire. Stick welding is also called arc welding; it is more difficult to understand than MIG welding. 

TIG welding is very versatile and the most challenging type of welding to learn.

Plasma arc welding is usually used for aerospace applications. It is a precise technique used when the metal thickness is about 0.015 inches. An example is an air seal or engine blade. 

The TIG welding technique has overtaken gas welding. It needs acetylene and oxygen, and it is very portable. This method is still used sometimes to weld parts of car exhaust

Which weld is strongest?

The strongest weld is the TIG (Tungsten inert gas welding) called the GTAW welding. TIG is used in producing solid and clean welds; it is the most rigid type of welding and for diverse reasons

It is also a tedious process that is difficult to master than various types of welding. It is also a prolonged process. 

What are the 5 basic welding joints? 

The most commonly used basic types of welding joints are the Lap joint, Tee joint, Butt joint, corner joint, and edge joint. 

What are the 5 welding essentials? 

This includes the; correct electrode size, right electrode angle, appropriate current, accurate travel speed, and voltage or length. This helps to produce uniform and smooth ripples for welding. 

Which welding is strongest? 

TIG welding is the strongest type of welding. It produces more precise and cleaner welds than other types of welding methods. It is higher in quality. 

Is TIG stronger than MIG? 

TIG is stronger than MIG. Tungsten Inert Gas welding is tough to learn, and it requires a very skilled operator because it needs simultaneous use of the foot and both hands

Although it is slower than the MIG and involves the surface of a workpiece to be entirely immaculate. The MIG weld also cools faster compared to TIG. 

What are the 4 basic weld joints? 

The four major essential weld joints are the Butt joint, Lap joint, Tee joint, and Corner joint. 

What are the 4 welding positions? 

These include flat weld, vertical weld, overhead weld, and horizontal weld

Conclusion

With this, it should be quite easy to determine which weld joint to use for a project. Remember that the selection of the right joint depends on the placement of the workpieces, the room for welding, and the strength of the workpiece. Always find out the proposed load for the structure to be welded and use the correct joint. 

Feel free to share your concerns. 

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