AC Welding vs DC Welding: Which One Is Better?

So what are the differences between AC and DC welding?

Right here and right now, we’ll figure out all of them and see what kind of perks these methods have to offer.

Find more details down below. 

DC Welding

DC stands for direct current, which means that an electric current has a consistent polarity flow that goes in a single direction. It can be either negative or positive.

The work principle of a DC welding machine is very simple, so there won’t be a problem for a welder with utilizing it. 

It is great for joining thin metals and it is also used for stick welding, which one of its forms is TIG. 

For DC reverse polarity method, the electrode ends up being positive, and current flows from the workpiece to the electrode.


  • Easy to start. This is also the reason why many say that DC welding is great for beginners.
  • Leaves a smoother and more stable arc.
  • Less spatter and sticking.
  • Can be a great option for thin sheet metals and weld metal.


  • It is a lot more expensive. It is caused by a need for DC currents for an internal transformer.
  • Can’t be used with high-intensity heat.

AC Welding

AC stands for alternative current. This one is almost the opposite for DC welding.

In this case, electric charge will move in a single direction only for half of the time and for the rest it will comes back.

In simple language, this is just a forth-and-back flow of electrons that keeps switching directions. It is capable of changing its polarity many times (this number can even be 100-120) per second.

Because of this effect, there is no deflection of the arc, since both the magnetic field and the current are changing directions quickly all the time.


  • AC welding machines are a lot cheaper. 
  • Quick and efficient aluminium welding.
  • It’s portable and can be used in different workplaces.


  • More spatter.
  • It’s not as smooth as DC welding.
  • Doesn’t cut as smoothly as a DC machine.
  • It’s not capable of fixing the arc blow.

AC Welding vs DC Welding: So What Is the Difference? 

As you can see, both AC and DC welding can be a great choice for welders. The final choice depends on your preferences.

Let’s take a look at some similiarities and differences these methods share. 


  • An AC welding machine is a lot cheaper than a DC one.
  • Maintaining an AC machine is easier.
  • A DC machine is larger and heavier.


  • Both can be useful for all kinds of tasks. 
  • AC and DC welding machines are commonly used everywhere.

Choosing the right current and polarity is often a key to successful and safe work. If you are still not sure which welding is best for you, just consider the kind of work you are about to do and based on that knowledge, you will know which welding method is the best one. 

AC Welding vs DC Welding (1)

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