What Is a Seam Weld? Advantages, Disadvantages, & More

The Welding process is an inextricable part of the metal fabrication industry. Different welding techniques are utilized to produce the best quality and reliable products. Since a product’s reliability depends upon the suitability and quality of the welding technique being used, it is critical to understand different welding techniques.

Without knowing the potential, suitability for different applications, advantages, and disadvantages of a particular welding technique, we can’t get the best out of it. Seam welding is a modern welding technique used in high-profile welding processes.

Unlike stitch welding, which is an intermittent process, it is a continuous welding process. If you are curious to know, What Seam Weld is? Give a read to this article. I’ve discussed the seam welding process, its properties, applications, and pros and cons.

What Is a Seam Weld?

Seam weld is a process used to join the pieces of similar or dissimilar materials in the continuous seam. It is a widely used welding technique that is used for both corner and flat welds. Seam welds feature higher strength than any other welding techniques since they are present throughout the length of a joint. A uniformly welded region created through seam welding in fusion binding is sometimes even stronger than the materials being joined.

Since the high strength is the key property of seam weld, it is mainly employed in the process where the strength of the joint is a paramount concern. Additionally, seam weld is a controlled technique in which a very low heat input is utilized to the under-process materials. The low input of heat minimizes the damage and helps maintain the original properties of materials. Therefore it is used in thin and delicate welding projects as well.

Depending upon the method of heat generation seam world is further divided into two main categories, Resistance Seam Weld and Friction Seam Weld.

Resistance Seam Weld

Resistance seam weld is a technique in which two copper electrodes work on the principle of metal resistance. When current is passed through the electrodes, an immense amount of heat is generated as a result of resistance between metallic electrodes.

The resistance seam welding is almost similar to continuous spot welding. The major difference between the two is the type of electrode. In resistance seam welding, roller electrodes are used, while static electrodes are used in continuous spot welding.

In resistance seam welding, the metal sheets being welded are held between the shape electrodes, and current is passed through them; the high heat production begins to melt the metal sheets held by rollers and results in the strong joint between them. The resistance seam welding could be either continuous or intermittent.

In intermittent roller motion, the speed of the roller is not fixed. However, in continuous resistance welding, we have a predetermined roller speed that is kept constant throughout the process. The average speed of continuous seam welding is around 60-inches/ minute, but it varies depending upon the thickness of the material, heat input, and sensitivity of the project.

Friction Seam Weld

In friction seam, weld materials are joined together in a solid phase. Neither of the material is melted in friction seam weld.  This method uses friction to generate heat instead of electrodes. This welding technique uses a rotating consumable bar with U or V shape groove. Also, have a look at how to join steel pipes without welding.

The material to be joined is pressed underneath the rotating consumable bar, and heat is generated through the friction process. No fusion of interfusion takes place during this process.

Resistance Seam Weld


Seam weld has multiple applications in metal fabrication projects. Here are some of the common applications of this high-strength welding technique.

Alloy Welding

Seam weld is used for welding different metal alloys like magnesium alloys, nickel alloys, and stainless steel work-pieces.

Fuel Tanks

Since seam weld is known for its high strength and reliability, it is used in the fabrication of vehicles and aircraft fuel tanks. Additionally, it is so used in making steel tanks and fuel cans since leakage risk is almost zero.

Refrigerators and Transformers

Metal fabrication during the manufacturing of refrigerators and transformers is a sensitive process. Seam weld is used to complete these sensitive welding projects.

Exhaust Systems

Resistance seam welding is used in the manufacturing of exhaust systems. Seam welding is a reliable and high-strength process and comes with its own advantages and drawbacks.


Fluid-tight and Airtight Seals

Seam weld produces airtight and fluid-tight seals, making this process highly useful for creating metallic structures that require gas, water, or liquid leakage protection.


No Overlapping

If you are concerned with the joint overlapping, choose seam welding. There are fewer chances of overlap production, and if it is produced, it won’t be thicker than 10mm.

Simple Operation

Unlike plasma and arc welding, seam welding is a simple and straightforward process. It is easy to learn, and even those not skilled yet can do the job.  Since it’s a fully automated process, there are fewer chances of human error.

Fast Process

Seam welding is a fully automated process with the automatic transfer, loading, and unloading of the materials. Since the metal does not include manual input or output, it’s faster than any other welding technique.

Controlled Process

The current is passed intermittently through the electrodes in this process, and heat produced is fully utilized in the welding process. The minimum amount of heat dissipation and maximum current utilization make the process cost-effective, time-saving, and environmentally friendly.


The automated setup makes the process highly repeatable. Therefore, this technique is utilized in big metal fabrication projects to increase production rate and achieve big targets under a limited time span.


Due to maximum labor input and faster processing, this is one of the most cost-effective welding techniques. The process saves a lot of money in terms of labor cost, time, and component transfer. It reduces the cost to about half of the original process.

Pollution-Free Process

The major pollution associated with the welding process is produced by the filtration material. Thankfully, no filtration material is used in seam weldings, and therefore, no solid waste is produced in this process. Since the process doesn’t produce any gas or fumes, its contribution to air pollution is almost zero.



Thickness Limitations

The thickness of metal sheets is the major concern of seam welding. It becomes difficult to handle the seam welds if the thickness of metal sheets is above 3mm.

Curved Welds Limitations

Resistance seam welding uses rollers that are ideal for producing high-strength uniform welds along straight lines. However, when it comes to the complex and curved welds, the process cannot handle them perfectly. This is one of the major limitations of this process.


What is seam welding used for?

Seam welding is used in high-strength metal fabrication projects. It is used to produce airtight and fluid-tight welds in the fuel tanks of aircraft and other vehicles. Also, seam welding has a wide application in metal and alloy welding, including nickel alloys, stainless steel, and magnesium alloys.

What is the difference between spot welding and seam welding?

The spot welding uses a single static electrode and works on intermittent welding techniques. The speed of post welding cannot be predetermined, and it is used to produce joints at irregular intervals.

In contrast, seam welding uses two rotating electrodes that are used to create continuous joints along the straight line. A high-strength uniform joint is formed between flat surfaces and corners. The speed of the seam welding process can be predetermined.

What are the advantages and disadvantages of seam welding?

Seam welding creates gas-tight and fluid-tight seals. Since it is a fully automated process, it saves you a considerable amount of time and cost. Also, less production of the waste is another advantage of the seam welding process.

The disadvantage of seam welding includes its inability to weld the sheets thicker than 4mm. Only highly skilled welders can help the sheets thicker than 3mm in seam welding. Also, it can not handle complex and curved internal joints.

Why is water used in seam welding?

The high level of heat is produced by metal resistance when the current is passed through electrodes. This intense heat is a requirement of the process to create airtight and fluid-tight seals. To prevent the seam weld wheels from melting, they are cooled by passing 1.5 gallons/min water through them.

Wrapping Up

I’m hopeful that this information will help you understand, What is a seam weld? Seam welding is a modern and stronger welding technique than stitch and spot welding. Since the welding technique does not contribute to water or air pollution, it is widely adopted by the major metal fabrication industries.

About Dave Walker

Dave Walker, a professional welder who has been welding from an early age. Now aims to help others by making them learning skills and finding them new opportunities. He has written for many welding blogs and helped many pursue their welding goals by helping them in choosing the best welding tools of the time.

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