Which gas mixture is commonly used for TIG welding stainless steel?

In TIG welding stainless steel, a mixture of helium and argon is commonly used because this combination provides several beneficial properties. Argon is a noble gas that offers excellent shielding capabilities, protecting the weld area from oxidation and contamination. It helps create a clean, stable arc and enables good bead appearance. When combined with helium, the mixture enhances heat input and increases welding speed, which is particularly advantageous when working with thicker materials. Helium has a higher thermal conductivity than argon, allowing for better penetration in the weld and improving the overall quality of the joint.

This mixture is often preferred for stainless steel because it results in a smooth, stable arc and produces high-quality welds with reduced chances of defects. The other gas options lack these optimal characteristics for stainless steel welding.