What Is Welding Gas?

Welding is one of the most widely used fabrication processes for joining metals and other materials. Welding plays an important role in many aspects of manufacturing, from construction to vehicle and mechanical assembly. But no welding process can be performed without the use of some type of welding gas.

In fact, over 4,000 million tons of welding gas is used annually in the United States alone! So what exactly is welding gas, and how does it facilitate the welding process?

In this article, we will explore the world of welding gas and break down some of the most important factors that make it important to the welding process.

What is Welding Gas?

Welding gas is used to fuel the welding process. It helps the heat generated during welding penetrate into the metal to be welded.

Gas is also used to provide an atmosphere for arc welding that eliminates air contaminants, such as oxygen and nitrogen, from entering the area and compromising quality weld penetration. Welding gas can come in a variety of forms, including mixtures, blends, and different kinds of gases.

Types of Welding Gas

  • Pure Gases
    • Argon – Commonly used as a shielding gas for MIG and TIG welding.
    • Helium – Commonly used as a shielding gas for TIG welding or for applications requiring very high heat input.

    • Oxygen – Commonly used as an oxidizing agent for cutting torches, welding torches, and brazing torches.
    • Carbon Dioxide – Commonly used as a shielding gas for MIG welding. Carbon dioxide acts as an oxidizing agent.

Mixed Gases

  • Argon/CO2 Mixtures – These mixtures are typically 80% Argon / 20% CO They are used for MIG welding and are especially effective on thicker metal where greater penetration is necessary.
    • Argon/CO2/Oxygen Mixtures – These mixtures contain 80% Argon / 20% CO2 and up to

      5% Oxygen. They are best used for spray arc welding, flat and vertical-up welding applications.

  • Helium/Argon Mixtures – These mixtures contain up to 50% Helium and 50% Argon. They are best used for welding in high-temperature operations, such as open-arc welding and GTAW (TIG). They are also good for the welding of aluminum alloys.

Blended Gases

  • Tri-Mix – Composed of 90% Argon / 5% CO2 / 5% Oxygen. It is used for both MIG and TIG welding, and provides better weld penetration, film integrity, and less splatter than shielded Argon mixtures.
  • Metal-Cored and Flux-Cored Wire – These wires use a mixture of gases, including Argon, CO2, and Oxygen, to enable easier welding of thicker metals.


As you can see, there are a variety of welding gases available, each of which is best suited to certain types of welding operations. Depending on the kind of welding you need to do, it is important to select the best option for your particular application. By choosing the correct welding gas, you will be able to achieve the highest-quality results for your welding jobs. Citation URL:https://www. airgas. com/welding-gashttps://www. millerwelds. com/resources/article-library/welding-gas-what-you-need-to-know

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