What Gas Is Best For Mig Welding?

Welding is a critical skill used across a variety of industries, especially in the manufacturing industry. It is far more complicated than it appears and a requirement for a long-lasting, solid weld is the choice between the right kind of gas.

As you read this article, you will learn about the various gases used for MIG welding and why one is generally considered to be the best for the job. Nearly 101 million individuals use MIG Welders around the world and over $12 billion is spent annually on MIG welding equipment and supplies.

So the question arises ,what gas is best for mig welding? Let’s find it out.

What Gas is Best for Mig Welding?

Mig welding, also known as Gas Metal Arc Welding (GMAW), is a fast and extremely versatile welding process that offers welders a wide range of potential applications.

Choosing the right gas for mig welding is an important part of ensuring good weld quality and maximum weld penetration. In this article, we will explore what gas is best for mig welding in various situations.

Gas Types

Mig welding itself requires a shielding gas of some kind.

The most commonly used shielding gases are Carbon Dioxide (CO2), Argon (Ar), and a mixture of the two. Each has its advantages and disadvantages which should be taken into consideration when choosing the appropriate shielding gas for a weld.

  • Carbon Dioxide (CO2): Carbon Dioxide is the most commonly used shielding gas for Mig welding. It produces very good weld penetration and works well on thin materials. The downside of Carbon Dioxide is that it produces oxides and can result in porosity in the weld.

  • Argon (Ar): Argon is a very inert gas, meaning it does not react with the metal being welded, making it a good choice for welding on stainless steel and aluminum. Argon also produces good weld penetration but can be more expensive than Carbon Dioxide.
  • Mixtures: Mixtures of Carbon Dioxide and Argon are also available and are often used for Mig welding on carbon steel.

    The advantage of these mixtures is that they combine the benefits of Carbon Dioxide and Argon, resulting in a good weld quality with less porosity.


When considering what gas is best for mig welding, one must also consider the application for which the weld will be used.

Each gas type has its benefits and drawbacks, which must be weighed against the specific needs of the application.

  • For general purpose welding on carbon steel, a mixture of Carbon Dioxide and Argon is often used. This combination provides good weld penetration and less porosity, while also providing the low cost associated with Carbon Dioxide.
  • Aluminum and stainless steel welding often requires Argon or a mixture that contains a large proportion of Argon. Argon is very inactive when compared to Carbon Dioxide, making it ideal for welding on these materials.
  • Thin metals often require higher concentrations of Carbon Dioxide to ensure good weld penetration.


In conclusion, the best gas for mig welding depends on the application and the type of material being welded. Carbon Dioxide is the most commonly used shielding gas and provides good weld quality and low cost. However, for some applications, Argon or a mixture of Carbon Dioxide and Argon may be more appropriate. It is important to weigh the advantages and disadvantages of each gas type and consider the application when selecting the appropriate gas for a mig weld. Citation URLs: https://www. millerwelds. com/resources/knowledge/types-of-shielding-gases-for-gma-weldinghttps://mppglobal. com/probably-best-mig-welding-shielding-gas/

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