Helium (He)

Helium is a light shielding gas that you mainly use in TIG welding to bring more heat into the material. This gives you better penetration and you can work faster, especially on thick plates or highly conductive metals like aluminum and copper. Unlike argon, the arc burns hotter and more aggressively with helium. But you have to be careful: the weld pool becomes more fluid and runs away more easily, and the higher heat can overheat the structure faster. If handled incorrectly, the risk of cracking increases, especially with high-alloy steels. In practice, you usually mix helium with argon to combine a stable arc and good heat input. Pure helium is expensive and requires a higher setting on the machine due to its higher dielectric strength. Start with an argon-helium mixture and adjust the gas flow by feel and weld appearance.