Informational Guide

What Gas For MIG Welding?

If you are just learning how to weld, you might wonder what equipment is needed. For example, what gas for MIG welding is most appropriate? In this guide, we cover your top questions, such as what gas is used for MIG welding and what is the gas pressure for MIG welding? 

What gas for MIG welder machines? You have a variety of choices to pick from for your shielding gases. It all depends on what your welding goals are and what kind of material you are using. You must think about the weld bead porosity, the price of the gas, the preparation, and the transfer process.  


Are you wondering what gas to use for aluminum MIG welding? Argon is a top choice if you are working with non-ferrous metals. In fact, 100% argon is helpful with magnesium, titanium, or aluminum. Pure argon creates a narrow penetration profile. This is ideal for butt or fillet welds.   

If you don’t need pure argon, you can use it in a mixture, which will be further dealt with in a few minutes. However, when compared with the argon mixture, pure argon creates a cleaner bead profile. 

Carbon Dioxide 

What kind of gas do you use for MIG welding? Most commonly, people use carbon dioxide as a shielding gas. It’s one of the least expensive to use, making it desirable for beginners. With pure CO2, you get a deep weld, which is extremely helpful when working with thicker materials. 

On the flip side, carbon dioxide creates a less stable arc and leads to more spatter, especially when it is mixed with another gas. Also, it can only be used with a short circuit process.  


Are you trying to figure out what shield gas for MIG welding? Consider the benefits of oxygen, a reactive gas. It’s used in a small amount with other gases to improve the weld pool penetration, fluidity, plus arc stability. If you want to know what gas to use for MIG welding steel, this might be a good option. It works well with stainless steel, low alloy, and mild carbon. 

Because it creates some oxidation, you don't want to use oxygen with all materials. It's not recommended with exotic metals, copper, magnesium, or aluminum.  

Argon CO2 Mix 

What kind of gas is used for MIG welding? If you find the need to use pure argon, that’s okay. However, most people prefer to use a mixture. A 75-95% argon and 5-25% CO2 mixture is ideal for a good weld quality and quick clean-up.  

This combination allows for an ideal spray transfer process, allowing for more productivity and superior weld quality. It also leads to great arc stability, reduced spatter and superior puddle control, making it even easier for new welders to use.   


Ready to learn about what type of gas is for MIG welding stainless steel? Helium is great with non-ferrous metals but is also helpful with stainless steel. It creates a wider, deeper penetration profile, which is what makes it a favorite with thicker materials. Typically helium is used at 25-75%, while argon is mixed the rest of the way. 

You can adjust these ratios to change the bead profile, travel speed, and penetration. However, you will spend more on helium than most other gases. You can also mix it with argon and carbon dioxide.  

Gas Used For MIG Welding

What Is The Gas Pressure For MIG Welding? 

What is the correct gas pressure for MIG welding? The regular gas flow depends on the nozzle diameter you are using and the conditions you are attempting to weld in. Generally speaking, with a 1/2” nozzle, you would set the flow between 22 and 27 CFH.  

What pressure should gas be for MIG welding with a 5/8" nozzle? These are normally set at 30 to 35 CFH, while the 3/4" nozzle would see pressures of 30-40 CFH. While these are general guidelines, you have other factors that come into play, such as if there is a wind that is working against you. That's why you must always be ready to adjust the gas pressure to fit your needs. With a bit of experimentation, you will get used to what's best.  

Can You Mix Gases For MIG Welding? (+ How To Guide) 

Do you know what gas mix for MIG welding? If you aren't looking to use pure gas for your application, creating a mixture might be the best option. Typically, argon is one of the most mixed gases. It can be mixed in a particular ratio with oxygen, carbon dioxide, and helium. 

What is the best gas mixture for MIG welding? In some cases, you might not find exactly what you need from a two-gas mixture. In those cases, it could be necessary to create a ratio of three gases. While these are available to purchase, they aren't as common as the regular mixtures.  

Mix Gases For MIG Welding

Frequently Asked MIG Welding Gases Questions 

Can I weld MIG with 100% argon? 

It's possible to weld with straight argon, and it is used in special circumstances. However, it's not normally preferable because the welding bead isn't as uniform, and it can be pretty narrow.  

Can I use straight CO2 for MIG welding? 

You can also use straight carbon dioxide for many welding purposes. However, this gas produces more oxidation than other options, so the weld porosity is increased, making it a less favorable option.  

How much gas do I need for MIG welding? 

If you have an average weld to perform, you will need 25-30 CFH of gas to finish it. On the other hand, thicker metals will require more, even up to 60 CFH, to create a good-looking weld. 

How much does a bottle of argon cost? 

Argon gas is one of the more expensive options to purchase. You could spend $300+ for a brand-new cylinder of argon. However, it’s more cost-effective to purchase one larger cylinder than several smaller ones.  


What type of gas is used for MIG welding? Not only are there several options, but you can also create mixtures. The gas you choose depends upon your goals and what materials you are using.