What Is The Difference Between Ac And Dc Welding?

It’s a question that perplexes many welder hobbyist and professionals alike – what is the difference between AC and DC welding? AC and DC welding both have different features and benefits, and understanding them can help you make better welding decisions.

The power source you choose depends on the welding equipment and technique, as well as on your project’s requirements. According to a survey, more than 78% of welders prefer AC over DC welding. In this article, you’ll learn the differences between AC and DC welding, which can help a welder make better decisions while working on any given project.

Let’s get started!


Welding is a process by which two pieces of metal are joined together with the help of concentrated heat, usually generated by electricity or gas/flame. In general, there are two welding processes i.

e. AC welding and DC welding, both of which have their own unique advantages and drawbacks. In this blog, we’ll take a look at the difference between AC and DC welding and which one is the better option for various welding jobs.

AC and DC welding

AC welding or Alternating Current welding is a welding process in which the electrode and other metal pieces switch its polarity from positive to negative and vice-versa. In AC welding, the metal pieces being welded are connected to an AC welding machine for a welding job. This welding method has a longer duration of time and the ability to penetrate deeper into the metal pieces being welded due to the change in polarity.

On the other hand, DC welding or Direct Current welding is a welding process in which the welding is done with one direct polarity which can be either positive or negative. In DC welding, the metal pieces being welded are connected to a DC welding machine.

This welding method has a shorter duration of time and can also penetrate deep into the metal pieces being welded. Furthermore, DC welding is sometimes preferred over AC welding due to its capacity of producing smoother arcs.

Advantages of AC and DC welding

Advantages of AC Welding

– AC welding is especially advantageous for welding thicker metal pieces because of its deep penetration capabilities.

– AC welding is also better for welding materials such as stainless steel or aluminum.

Advantages of DC Welding

– The shorter duration of time creates a lot of advantages such as better arc control and less distortion.

– With DC welding, a much smoother arc is produced which helps in producing a better finish on the weld. – DC welding also allows for easier welding in tight places which makes it a preferred choice for welding in a large number of applications.


In summary, AC welding is typically used in welding jobs which require more penetration while DC welding is used in jobs which require a smoother arc. Both of these welding processes have their own merits and demerits and it all depends on the welding job in terms of which one should be used. Citation URLs: – https://en. wikipedia. org/wiki/Welding – https://www. multicutfintech. com/blog/difference-ac-dc-welding- https://www. thefabricator. com/thefabricator/article/welding/integrating-ac-welding-into-your-shop – https://www. multicutfintech. com/blog/ac-dc-welding-polarity

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