The gas used for MIG (Metal Inert Gas) welding, also known as GMAW (Gas Metal Arc Welding), depends on the type of material being welded and the desired weld properties. The four most common shielding gases used in MIG welding are:
- Argon: This gas is often used for MIG welding aluminum and provides good arc stability and weld penetration.
- Carbon Dioxide (CO2): CO2 is frequently used on its own or as a small percentage of a helium or argon gas mix. It offers good penetration but can produce more spatter.
- Oxygen (O2): Oxygen is a reactive gas that can be added in small amounts to stabilize the arc, improve fluidity, and enhance the quality of the weld deposit.
- Helium (He): Helium can be added to increase penetration and fluidity of the weld pool. It is sometimes used in combination with argon and CO2 for welding stainless steel.
The most popular gas for MIG welding is a 75% argon and 25% CO2 mixture, often referred to as C25 or 75/25 gas. This gas provides a good balance of arc stability, spatter control, and weld penetration, making it suitable for a wide range of applications.
