Mig welding gas pressure is one of the most important settings when it comes to successful welding projects.
Without using gas pressure for Mig welding, it can result in poor welds that lack quality, resulting in welds that look almost like scar tissue from a deep cut or burn.
In this article, I will go into detail about the variables involved in gas pressure for Mig welding projects. Make sure to read the full article to learn about gas pressure requirements for Mig welding.
MIG Welding Gas Pressure
Mig welding gas pressure is the amount of pressure in the gas bottle. Most MIG welding gas pressures are between 3 and 8 PSI. The higher the pressure, the hotter your weld will be. If you have high pressure at low amperage, it can cause problems with weld penetration, so be careful as you adjust this setting.
It is an important part of making sure you get a good weld. The pressure you use will depend on the type of metal you’re working with, but generally speaking, I think that the higher the pressure, the stronger your weld will be.
I suggest that you’ll want to use a low-pressure setting if you’re MIG welding aluminum or stainless steel. You’ll also want to use a high-pressure setting for steel or other hard materials. Keep reading!
Gas Flow & Gas Pressure Comparison
The gas flow and gas pressure in MIG welding have a lot of overlap, but they’re not the same thing.
Gas flow refers to the amount of gas that’s flowing through the torch, and it’s measured in cubic feet per hour (cfh).
Gas pressure refers to the amount of pressure that’s being applied to the metal you’re welding, and it’s measured in pounds per square inch (psi).
When you change one variable, like increasing your gas flow, you’ll also change the other variable: increasing your gas flow will increase your gas pressure.
How Much Argon Pressure for MIG Welding?
The amount of argon pressure you need for MIG welding depends on a few factors, including the thickness and type of material you’re working with, as well as whether you’re using an aluminum or steel wire.
The amount of argon pressure required for MIG welding also depends on what kind of gas regulator you have. If you’re using a standard regulator, then I recommend that the minimum pressure would be 30 psi.
However, if you’re using a regulated gas system, then I suggest the minimum pressure would be 40 psi.
As long as your equipment is set up correctly and calibrated regularly, it should stay within those parameters.
If you find that your equipment isn’t operating properly or isn’t working at all, for example, if there’s no flow of gas or if there’s too much flow, then it may indicate that something has gone wrong with your regulator or other parts of your setup.
Argon Gas Tank Limit for MIG Welding
Now, I will tell you about the gas tank (argon) specifications for the purpose of MIG welding through this table. These figures may vary according to manufacturer changes in the tanks.
| Tank Size | Tank Height | Full Weight | Empty Weight | Max. Pressure |
| 40 cf | 21.5 inches | 27 lbs | 23 lbs | 2015 |
| 80 cf | 34.5 inches | 55 lbs | 46 lbs | 2015 |
| 120 cf | 44.5 inches | 70 lbs | 57 lbs | 2265 |
Note down that the diameter sizes for the above-mentioned tank sizes are the same, i.e., 6½ to 7¼. Before buying any tank, I recommend that you should consider all the specifications earlier.
Minimum Gas Flow Rate
Gas flow rate is a crucial factor in MIG welding. The minimum gas flow rate for MIG welding depends on the type of material you are welding and the thickness of your material.
The minimum gas flow necessary for MIG welding depends on the type of metal you are working with, as well as its thickness. For example, steel requires more gas than aluminum because it has a higher melting point.
Therefore, if you are working with thinner pieces of steel, you will need less gas than if you are working with thicker pieces of steel.
I recommend using a minimum gas flow rate of 20 cubic feet per hour, depending on the thickness of your weld. For example, if you are welding mild steel, use a flow rate of up to cubic feet per hour.
You can also adjust your gas flow rate based on the material you’re welding and how much heat is needed to melt it. If you’re welding thin sheet metal, turn down your gas flow rate as low as possible so that you don’t overheat the metal.
Maximum Gas Flow Rate
In MIG welding, the gas flow rate is measured in cubic feet per hour (CFH). The optimal amount of gas flow depends on the type of metal you are welding as well as the thickness of the material.
If you are welding thin materials, like thin sheet metal or thin sheets of welded wire mesh, a flow rate of between 15 and 20 CFH is optimal. This will give you enough shielding gas to protect the weld area but not so much that it causes turbulence in your arc or reduces its brightness.
For thicker materials, like 1/8-inch steel plates, a gas flow rate between 20 and 25 CFH works best. This will provide enough protection against oxidation without causing too much turbulence in your arc or reducing its brightness.
If you find that your arc is too bright when using a higher-than-recommended flow rate, try lowering it until it becomes more stable and less prone to sputtering.
Gas Flow Rate Table
Below is the MIG gas flow rate (minimum & maximum) table for different nozzle sizes. I recommend that you do not exceed the below-mentioned limits to avoid welding issues.
| Nozzle Diameter (MIG Gun) | Normal Flow (CFH) | Minimum Flow (CFH) | Maximum Flow (CFH) |
| ⅜ inches | 17 to 21 | 10 | 30 |
| ½ inches | 21 to 26 | 18 | 40 |
| ⅝ inches | 29 to 34 | 22 | 55 |
| ¾ inches | 29 to 39 | 30 | 65 |
Different Gas Flow Rates for Different Metals
When you’re welding with a MIG welder, there’s a flow rate that’s right for the material you’re using. The flow rate will affect your weld quality and weld penetration, the amount of steel that is actually being melted into the joint.
Using the wrong flow rate can cause problems with your weld quality, which will make your project look bad or cause it to fail. That’s why I want to share this point with you so that you can easily know the MIG gas flow rate for different metals.
Following is the complete information on the MIG gas flow rate of three main metals, i.e., stainless steel, mild steel & aluminum:
1. Stainless Steel:
Stainless steel requires a higher gas flow rate than other materials. This is because of the way that the stainless steel reacts to heat.
When the material is heated by the electric arc created by the welder, it becomes more reactive, and this causes it to lose its shape. The higher gas flow rate helps to keep the material cool and prevents it from losing its shape. For stainless steel, I recommend that you should start from 20 to 25 CFH.
At constant pressure, increasing the gas flow rate results in more helium consumption. The exact amount of helium consumed increases as the total flow rate increases.
Helium has a low thermal conductivity, so it flows through stainless steel quickly. You may create concentrated heat spots if you don’t manage your heat input.
Helium is quite lighter than argon & CO2, and you may face porosity issues if not too much helium exists & you do not use the high flow rate. So, I recommend that high gas flow rate while MIG welding stainless steel.
2. Aluminum:
The gas flow rate for aluminum is the highest since it has a lower melting point than other metals. Aluminum melts at a relatively low temperature compared to other metals.
The lower melting point makes it easier and less time-consuming to work with but also makes it more prone to thermal runaway when welding because of its susceptibility to oxidation. For aluminum MIG welding, I recommend that you should keep the gas flow rate at 30 CFH.
If you want to weld thick, then I recommend that you should go for more helium & less argon because helium is best for this purpose. If you use helium & argon then remember that the gas flow rate should be more than 40 CFH.
3. Mild Steel:
To control the temperature of a weld and avoid burn-through, the gas flow rate needs to be set correctly. The correct flow rate is typically lower for mild steel than it is for stainless steel.
If you want to MIG weld mild steel with 75% argon & 25% CO2, then the recommended gas flow rate should be 10 to 15 CFH. In case of porosity issues, the gas flow rate must be 20 to 30 CFH.
How can you Adjust Gas Pressure?
Adjusting the gas pressure on a MIG welder is easy and straightforward.
To get started, make sure your MIG welder is unplugged from the outlet. Then, locate the gas regulator on top of the machine.
If you don’t see one, look for a gauge that controls the flow from the gas tank to your welder’s torch. This will be on the side of the machine or underneath it.
The regulator has a dial that can be used to increase or decrease pressure in your gas tank. This will allow you to adjust how much gas flows into the weld area so that it is at an optimal level for optimal welding results!
Which Type of Gas is Used in MIG Welder?
The main types of gas used in MIG welders are:
- Argon
- Helium
- CO2
Argon:
Argon is the most common type of shielding gas for MIG welding. It creates a stable arc that reduces splatter and improves weld quality.
Argon can also be used with Flux-Cored (FCAW) welding to protect the flux core from oxidation, which can cause it to clog the nozzle or blow out of the joint.
Helium:
Helium has many uses in welding because it is an inert gas; it doesn’t react with other elements or compounds and causes no corrosion or oxidation when used as a shielding gas.
It’s best suited for applications where you want to improve the quality of your welds while maintaining a stable arc that reduces splatter and produces clean welds.
CO2:
CO2 is another popular choice because it provides excellent penetration while producing clean welds in all positions, even overhead!
However, I do not recommend to use of aluminum because it doesn’t provide adequate protection against oxidation during welding operations.
Conclusion:
The most important thing to remember while adjusting your MIG welding gas pressure is the type of metal you are working with and the thickness of the metal.
A gas pressure of between 3 and 20 PSI is usually ideal. If you’re looking for a small, general-purpose MIG welding machine for use at home, this range should cover the vast majority of jobs you might encounter.
Make sure to read this article’s guidelines on gas pressure for MIG welding projects so that you have a better idea.
FAQs:
What should I set my MIG welding regulator to?
Your MIG welding regulator controls the flow of gas used in your MIG system. The amount of gas flow depends on many factors, but it is most commonly set to a value between 20 and 25 cubic feet per hour (CFH).
What is the correct gas flow for MIG welding?
When setting up a MIG welder, the most important factors to consider are the type of metal being welded and the type of wire being used. Normally, the starting point should be 20 to 35 CFH.
How much is argon gas for MIG welding?
The amount of argon gas needed for MIG welding depends on the type of shielding gas used and whether it is CO2 or a mixture. Argon is a preferred gas when you are welding high-carbon steel. It can produce clean welds with little penetration and minimal porosity. You need 75 to 95% argon gas for MIG welding.
What pressure is shielding gas?
For a shielding gas to be most effective, it must be at high enough pressure to prevent rapid oxidation of parts. Typically, the pressure is set at 5 to 15 psi or so. Lower pressure allows air to leak through leaks in the shielding gas supply equipment and escape out through the nozzle being used. At too low a pressure, oxidizing agents can penetrate the nozzle tip and attack workpieces.
What are the 2 main settings of a MIG welder?
The 2 main settings that are of most importance with a MIG welder are voltage and wire feed speed. These two settings can have a huge impact on the quality of your welds and should be set according to the type of metal being used, its thickness, and whether or not you’re welding aluminum.
