Metalworking professionals mostly use MIG MAG welding techniques but distinguishing between them can be very difficult. This guide clarifies these processes, highlights their important differences and outlines their practical uses. It will help you to select the right welding method for your particular project.
What is MIG MAG Welding?
These welding methods are used to join two metal parts during the metal fabrication process. Both of them use shielding gas and a wire electrode (continuously fed) to produce an arc. Despite having similarities, they are different in their metal uses and gas composition.
Process of MIG MAG Welding
Let’s look at how MIG and MAG work. Starting with MIG.
Process of MIG Welding
MIG uses an accurate electrical system and mostly uses 50-300 amperes and 18-32 volts. The process starts by feeding a wire electrode through the welding gun at 2 to 20 meters per minute. When you activate the gun, it creates an electric arc between the work piece and wire. This melts the wire to make a weld pool.
Inert gases like helium or argon are very important in MIG welding. These gases while flowing at 8-20 liters per minute, make a protective shield around the weld area. This barrier stops contamination from the air which can affect the weld’s strength. This guarantees a clean and sturdy bond without flux.
MIG welding machines have many different parts.
- A power source supplies the required electrical current.
- A wire feed unit continuously delivers the electrode wire.
- The welding gun contains the wire and controls the flow of the shielding gas and the wire.
- A gas cylinder usually holding 40-50 cubic feet of inert gas completes the configuration.
Process of MAG Welding
MAG welding is the same as MIG welding but has one big difference. Like MIG welding, it also uses a consumable wire electrode that goes through a welding gun to make an arc that melts the base metal and wire. But contrary, the MAG technique uses a mixture of active gases mostly oxygen (O2) and carbon dioxide (CO2).
The active gas affects the chemical composition of the weld.
At arc temps of 6,500°C, the gas partly breaks down. It results in addition of reactive elements to the weld pool. These elements can change the properties of the weld. This usually increases the fluidity of molten metal and the penetration depth.
While MAG machinery looks like that of the MIG, it has some important differences.
- The power source must handle higher currents, mostly up to 600 amperes.
- Wire feeders need to fit larger wire diameters, mainly 0.8 to 1.6 mm.
- Moreover, the gas regulator must accurately control the active gas mix flow to make sure the best weld traits till the end of the process.
7 Key Differences between MIG and MAG Welding
Although both techniques seem similar, they have some differences. Here are the seven main differences:
1. Gas Used
MIG process uses Helium or argon (99.9% pure) as an inert gas. For MAG, active gases or blends with 20-25% CO2 and 75-80% argon are used.
2. Gas Behavior During Welding
In MIG welding inert gases stay stable during the entire procedure. But in MAG welding active gases partially break down with CO2 decomposing into oxygen and carbon monoxide at arc temperatures.
3. Influence on Weld Bead
MIG welding makes clean welds with little oxidation because the inert gas doesn’t interact with the weld pool. Active gases in MAG process react with molten metal. It leads to a change in penetration depth and bead shape.
4. Chemical Composition Changes
MIG welding keeps the original metal composition. On the other hand, MAG welding can modify the chemical composition of the weld. For example, the carbon content may increase by 0.05% to 0.15% which maximizes strength but mostly decreases ductility.
5. Flexibility in Gas Usage
Pure inert gases limit MIG welding options. MAG welding has more flexibility with different mixtures of gas. Adjusting CO2 from 8% to 25% increases the stability of the arc and penetration.
6. Cost
Higher running costs are common in MIG welding due to overpriced inert gases ($15-$30 per cylinder). MAG welding is more reasonable with active gas mixtures that cost $10-$20 per cylinder and decreases the expenses of the operation.
7. Preferred Applications
Non-ferrous metals like aluminum benefit from MIG process. It acquires deposition rates up to 5 kg/hour.
MAG welding is great with ferrous metals. It has a deposition rate that reaches 8 kg/hour and acquires a penetration depth of 25mm in steel.
Comparison Table
| Key Differences | MIG Welding | MAG Welding |
| Gas Used | Inert gases like helium or argon | Active gases such as gas mixtures or CO2 |
| Chemical Composition Changes | Keeps original composition | Can change chemical composition |
| Gas Behavior During Welding | Gas remains stable | Active gas partially breaks down |
| Influence on Weld Bead | Spatter-free and clean welds with smaller bead widths | Larger beads with higher reinforcement |
| Preferred Applications | Great in non-ferrous metals | Good for ferrous metals |
| Cost | Higher operational costs due to high-priced gases | More budget-friendly with less gas costs |
| Flexibility in Gas Usage | Limited to pure inert gases | It allows gas mixtures |
Interested to know about more sheet metal welding methods?
Take a look at our related blog post: Sheet Metal Welding –The Complete Guide
Applications of MIG and MAG Welding
After looking at the differences, let’s examine how these welding methods are used in different industries.
MIG Welding
MIG welding is famous in many areas because of its flexibility and accuracy:
- Automotive Industry – Benefits from MIG’s ability to join thin sheets (0.6-3 mm) with minimal distortion. MIG is specially good for steel frame parts and aluminum body panels that have tensile strength of over 280 MPa in aluminum alloys.
- Aerospace – In aerospace lightweight and non-ferrous metal joining heavily depends on MIG welding. Its deposition rates of 2-5 kg/hour for aluminum parts meet strict. Here MIG is mostly used in wing structure fabrication and fuselage assembly.
- Home and DIY Projects- Hobbyists prefer MIG welding for its user-friendly nature. As thin as 0.5 mm materials can be welded with 30 amp currents which makes it perfect for repairs and small fabrication. It’s common for garden equipment fixes and custom furniture.
MAG Welding
Tough jobs usually use MAG welding for its multi-functional nature and speed:
- Construction and Heavy Fabrication: Steel machinery and structures building depend on MAG welding. Bridges and high-rises benefit from its ability to join 25 mm thick plates in one pass.
- Pipeline Welding: MAG welding is integral here because it permits deep 8 mm penetration. Big oil and gas pipelines are mostly joined this way.
- Shipbuilding: MAG welding’s cost-effectiveness and strength make it important for marine uses. Deck plating and hull building commonly apply this method to produce a weld with a tensile strength of 400-600 MPa in steel.
5 Advantages and 3 Disadvantages of MIG MAG Welding
Now that we’ve covered their uses, let’s weigh the pros and cons of MIG and MAG welding.
| Aspect | MIG Welding | MAG Welding |
| Advantages | 1. Great for Thin Materials: Accurate heat control prevents burn-through on sheets as thin as 0.6 mm. 2. Simple to Use: Easy for beginners with automatic wire feeding. Needs little training which can decrease fatigue of operators. 3. Clean Welds: Makes minimal spatter. Post-weld cleanup time cut by up to 50% compared to stick welding. 4. Versatile: Good for multiple metals in which stainless steel, aluminum and copper alloys are involved. Can weld materials as thin as 0.5 mm. 5. Faster Welding: Acquires speeds up to 30 inches per minute on thin materials. Increases productivity by 30-50% over stick welding. | 1. Cost-Effective: Uses less overpriced gases like CO2. Operational costs 20-40% lower than MIG welding. 2. Stronger Welds: Perfect for thicker, ferrous metals. Achieves penetration depths up to 25 mm in a single pass. 3. Minimal Slag Production: Decreases post-weld cleaning time by up to 40% compared to stick welding. 4. High Welding Speed: Proficient for large-scale production. Travel speeds of 250-400 mm/minute are possible. 5. Industrial Applications: Largely used in heavy-duty industries. Can handle steel plates up to 50 mm thick with multi-pass methods. |
| Disadvantages | 1. Higher Costs: Inert gases can cost $15-$30 per cylinder which increases operational expenses. 2. Sensitive to Environment: Wind speeds above 5 mph can disperse shielding gas by which weld quality can be affected. 3. Material Limitations: Less effective on materials thicker than 10 mm without advanced techniques. | 1. Fume Generation: Produces up to 30% more fumes than MIG welding. Requires maximized ventilation systems. 2. Complex Setup: Requires exact control of gas flow (14-20 L/min) and machinery settings for best performance. 3. Limited Positioning: Usually restricted to horizontal and flat welds. Overhead welding requires advanced techniques. |
Safety Considerations in MIG MAG Welding
Safety is integral in welding. Here are some very important points to remember when using MIG or MAG welding.
Common Hazards
Welders face many possible dangers:
- Inhalation of welding fumes produces up to 150 mg/m³ of particulate matter which can pose serious health risks
- Electric shock is possible with currents that range from 30 to 350 amperes
- Burns are a risk because of arc temperatures reaching 6,500°C
- Sparks from welding can ignite flammable materials within a radius of 10 meters
- Arc radiation can lead to “arc eye” within 6-8 hours of exposure
Safety Equipment and Best Practices
Welders should follow these practices to minimize risks:
- Use insulated gloves rated for up to 1000V. Assure proper ventilation with 100-150 cfm airflow
- Wear flame-resistant clothing covering all exposed skin
- Set up welding screens to shield others from arc flash
- Keep the workspace dry, clean and free of flammable materials
- Use auto-darkening helmets (shade levels 10-13)
Workplace Safety Protocols
Proper safety protocols are important to prevent welding accidents:
- Create assigned welding areas with 3-hour rated fire-resistant barriers
- Perform quarterly safety audits
- Train staff members on emergency procedures which include a 30-second fire response
- Keep air quality in check (Ozone below 0.1 ppm, CO below 50 ppm)
- Certify proper grounding with resistance less than 1 ohm
- Implement a lockout/tagout system for all welding machinery
- In every 500 hours of use, check the electrical integrity of the machinery
Conclusion
MIG and MAG welding both give special advantages for different uses. MIG creates accurate and clean welds for non-ferrous metals and MAG gives affordable and durable welds for ferrous materials. After knowing about these differences, you can pick the best process for your needs.
Need professional-level MIG or MAG welding services? KDM Fabrication is the best choice. Contact us today to discuss your project and get expert guidance.
Frequently Asked Questions
Which process produces strong joints – MIG or MAG welding?
Both can make heavy-duty joints. The main difference is not weld strength but the shielding gas. These methods such as GMAW variants can produce long-lasting and best-quality welds that are good for many manufacturing uses.
How to ensure joint quality in MIG MAG welding?
To get best welds in MIG MAG: focus on proper joint preparation and clean the surfaces well. Use appropriate weldings and correct parameters. Set right voltage and wire speed. Maintain proper gun angle and travel speed when welding. Also, use the correct gas mixture. Make sure that there is a good fit-up between workpieces. Follow these steps for way better weld quality.
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What is MIG MAG welding? Learn key differences, applications, and benefits to choose the right welding technique for your metal fabrication needs.
