What Gas Is Used for Mig Welding: Benefits of Using Argon

what gas is used for mig welding

MIG welding is a popular method of giving the steel a great weld and finish. Welders use several shielding gases to ensure the non-contamination of weld puddles.

The two most commonly used include 100% CO2 and carbon-argon mixture.

We will tell you about both and the benefits and when to use which. If you want to know what gas is used for MIG welding, read on!

What Gas Is Used for MIG Welding?

When it comes to MIG welding steel, there are two types of gases used primarily. These include 100% CO2 and another, a mixture of carbon and argon in 1:3 proportion. Though there are others, they aren’t as frequent.

You should easily procure both these gases from any local welder who deals in welding supplies. They are available in cylinders that are car-friendly and can be bought in any size, depending on your needs.

Using Argon in MIG Welding

The best part about argon is that it is an inert gas and resistant to the chemical change steel surfaces are prone to. Because of this firm protection it offers, it has become a popular gas for welders.

There are different ways of using argon. It can either be used in purity or as a mixture with carbon. Combining it with carbon makes it more potent in penetrating steel surfaces.

Benefits of Using Argon in MIG Welding

There are several benefits to using argon in MIG welding because it is a high-performing inert gas. This includes:

  • Highly reduced spatter during the welding process
  • Cheaper than other inert gases such as helium
  • Argon helps keep the welding arc stable.

Are There Any Cons of Using Argon in MIG Welding?

Argon is a great gas used in MIG welding, but only argon in its pure form can lead to a couple of problems that include the following:

It is very expensive, and a professional welder may need to significantly mark up their service to use argon in pure form. This may be a deterrent for many people.

A high argon concentration is known to drop the arc penetration rate in the steel.

Using Carbon in MIG Welding

Carbon is another gas that is used widely for welding purposes. Though it offers only moderate resistance to chemical changes affecting steel, it creates great results when mixed with an inert gas such as argon.

When mixed with argon, it offers great protection and keeps the costs in check, which is often a concern with inert gases.

Benefits of Using Carbon in MIG Welding

There are several benefits of using carbon in MIG welding. These include the following:

  • Offers great penetration of arc in welding processes.
  • Reduces porosity significantly when mixed with a substance such as argon.

Can You Use 100% Carbon for Shielding?

The simple answer is yes, although there are caveats to this. If you aren’t too fussy about the final look of the steel, you can go with pure carbon as it would help you save a lot of money. It will definitely provide protection to the steel surface.

A word of caution is that pure carbon should never be used on thin surfaces because it is not conducive.

Disadvantages of Using Pure Carbon for MIG Welding

Though it helps you keep costs in check, there are some downsides to using pure carbon for MIG welding. These include:

  • Creates a moderate amount of smoke during the welding process.
  • It sputters a great deal, which means you need to thoroughly clean up after the process.
  • Doesn’t provide a professional, fine finish.

Carbon Argon MIX for MIG Welding

This is probably the best mixture you could use for MIG welding. Most professional welders use it as the best solution to a great finish. The most common proportions include 75-25 and 80-20, with argon in higher quantity.

Benefits of Carbon Argon MIX for MIG Welding

There are several benefits to going for a combination of carbon and argon. This includes:

  • Better quality finish.
  • This combination is more compatible with delicate and thinner surfaces.
  • Better value for money as opposed to using argon alone.

What Other Gases Are Used for MIG Welding?

Some inert and semi-inert gases are used for MIG welding, but they aren’t as popular as carbon and argon. These include:


Helium is an inert gas that works just like argon in MIG welding. It is known to create an even deeper weld than argon. However, it is prone to use more power than argon and, as a result, can potentially lead to overheating and burnout.

Additionally, it is even more expensive than helium, which is a definite disadvantage. The costs are one of the primary reasons welders don’t work with argon, and helium takes it a notch higher.


Oxygen is also used in MIG welding sometimes though use is not very common. It is non-inert and used in very small amounts to make the arc more stable. It is used for thicker metals and stainless steel.

If one is not cautious and uses oxygen in a higher quantity, it can be detrimental, leading to the oxidization of the metal. Therefore, the permissible oxygen levels are between 1-5% when used in conjunction with other gases.


One can’t say which gas is the best for MIG welding with absolute certainty. For reasons discussed above, one must consider the merits of individual projects, the budgets, and the finish required to decide.

While you are at it, you must also consider your skill with individual gases, determining your productivity on the project. You may also need to use different combinations for different projects, as with most welders.

Therefore, it is imperative to familiarize yourself with the inert and non-inert gases used for MIG welding and take every assignment on a case-by-case basis.

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