In CNC manufacturing, welding is a vital joining process. MIG (metal inert gas) welding and TIG (tungsten inert gas) welding are the two most common welding methods, each suitable for different materials, process requirements and production goals. In this guide, I will compare the core differences, advantages and disadvantages of these two technologies and their applicable scenarios in detail to help you choose the best welding method based on accuracy, cost, production efficiency and material properties.
What Is MIG Welding
MIG welding (Metal Inert Gas Welding), also known as gas shielded metal arc welding (GMAW), is an automatic or semi-automatic arc welding method widely used in industrial production. Its main advantages are fast welding speed, relatively simple process, and applicability to various metal materials, especially in mass production environment with extremely high production efficiency.
Basic Principles Of MIG Welding
The core working principle of MIG welding is to form an arc through a fusible electrode with automatic wire feeding , so that the metal melts and fills the weld, and an inert or semi-inert gas (such as argon, carbon dioxide) is used as a shielding gas to prevent oxidation and contamination of the welding area. During the welding process, the electrode wire is continuously fed into the molten pool through the welding gun, and the arc melts the metal and forms a weld. This feature makes MIG welding have a higher degree of automation , especially suitable for mass production scenarios.
Commonly Used Gases And Their Functions
- 75% Argon + 25% Carbon Dioxide : Most commonly used in MIG welding of mild steel and stainless steel. Carbon dioxide can increase weld penetration and improve weld strength, while argon can stabilize the arc and improve weld quality.
- Pure Argon (100% Ar) : Mainly used for welding of non-ferrous metals such as aluminum alloys and magnesium alloys, because argon can reduce spatter, improve the surface finish of the weld, and reduce the size of the heat-affected zone, thereby reducing metal deformation.
- Helium-Rich Gas Mixture (He-Ar) : Used for welding of high thermal conductivity metals such as copper and titanium. Helium can increase welding penetration and enhance adaptability to high thermal conductivity materials.
Applicable Materials And Welding Thickness
MIG welding is suitable for a variety of metal materials, especially when welding thick plates over 1mm . The following are the MIG welding parameters for several common materials:
- Mild Steel : Commonly used in automobile manufacturing, building structures, etc. The typical welding thickness is 1mm – 25mm , and the welding speed can reach 400mm/min .
- Stainless Steel : Used in food processing equipment, medical devices, etc. The welding thickness range is 5mm – 12mm , and high-precision control is required to avoid excessive heat-affected zone.
- Aluminum Alloys : Used in aerospace, shipbuilding, etc. The typical welding thickness is 5mm – 10mm . Pulsed MIG welding is required to reduce spatter and optimize penetration.
Speed Advantage Of MIG Welding
With TIG welding, MIG welding has a clear advantage in production speed. Experimental data shows that MIG welding is usually 2-5 times faster than TIG welding . The specific welding speed depends on the material type, welding current and voltage. For example:
- Welding 3mm Thick Mild Steel Plate , The typical speed of MIG welding is 500-600mm/min , while TIG welding is usually only 100-200mm/min .
- Welding 5mm Thick Aluminum Plates , the deposition rate of MIG welding can reach 7-10kg/h , which is about 3 times faster than TIG welding and is suitable for mass production needs.
Typical Applications Of MIG Welding
Due to its high efficiency and stability, MIG welding is widely used in the following fields:
- Automobile Manufacturing : MIG welding is often used for car body welding to ensure high-strength connections. For example, in a car frame welding project, I used MIG welding technology to optimize the joint design, which increased the welding speed by 35% and reduced the weld defect rate to less than 2% .
- Sheet Metal Processing : Suitable for welding steel plates with a thickness of 2mm~10mm . The weld quality is stable and the welding cost is low. It is widely used in electrical cabinets, housings and other products.
- Heavy Structural Welding : In industries such as construction, shipbuilding, and railways , MIG welding can effectively improve production efficiency. For example, in a bridge steel structure project, after using MIG welding, the welding efficiency increased by 40% , and the processing time of a single weld was shortened by 2 hours .
MIG welding has become the preferred welding method in industrial manufacturing due to its advantages of high automation, fast welding speed and wide application of materials . MIG welding is undoubtedly a better choice for mass production, thick plate welding and structural parts manufacturing. However, in high-precision and thin plate welding scenarios, MIG welding may not be as fine as TIG welding. Therefore, when choosing a welding method, it is necessary to combine the material type, weld requirements and production goals to obtain the best processing effect.
What Is TIG Welding
TIG welding (Tungsten Inert Gas Welding), also known as gas tungsten arc welding (GTAW), is a high-precision, spatter-free, slag-free welding technology that is widely used in high-demand precision manufacturing industries. Compared with MIG welding, TIG welding provides more stable molten pool control and more detailed weld quality, and is suitable for metal materials with high strength and corrosion resistance requirements.
Basic Principles of TIG Welding
The working principle of TIG welding is to use a non-melting tungsten electrode to generate a high-temperature arc on the metal surface, melting the base material and forming a weld. Depending on the welding requirements, you can choose whether to add filler metal. During the welding process, 100% argon is used as a shielding gas to prevent oxidation of the welding area and ensure that the weld is pure and pollution-free.
Key Technical Features Of TIG Welding:
- Non-Melting Tungsten Electrode : As the heat source of the arc, it will not be consumed, ensuring the stability of the weld.
- Independent Filler Material : filler metal can be fed manually or automatically as needed during welding to improve weld strength.
- Current Control : Adjust the current using the foot controller or welder for precise heat input control.
Commonly Used Gases And Their Functions
Gas protection is essential for TIG welding. The following are the uses of common gases:
- 100% Argon (Ar) : The most commonly used shielding gas, which can effectively prevent oxidation, improve the purity of the weld, and is suitable for all metals.
- Argon-Helium Mixture (Ar-He) : Used for high thermal conductivity metals such as aluminum and copper. Helium can increase the arc column temperature and enhance the penetration depth.
- Argon-Hydrogen Mixture (Ar-H2) : Suitable for welding of certain stainless steels. Hydrogen can increase the fluidity of the molten pool and improve the smoothness of the weld.
Applicable Materials And Welding Accuracy
TIG welding is suitable for a variety of metal materials, especially for welding thin-walled, corrosion-resistant and high-strength materials. The following are TIG welding parameters for common materials:
- Aluminum Alloys : Mainly used in the aerospace and automotive industries, the welding thickness range is 0.5mm – 5mm, and AC TIG welding is used to remove the oxide film.
- Stainless Steel : Suitable for food processing equipment, chemical industry and medical equipment. The welding thickness range is 0.3mm – 6mm. The weld is dense after welding and has excellent corrosion resistance.
- Titanium Alloys : Used in medical implants and aviation parts, with a welding thickness of 0.5mm – 4mm, and the weld strength can reach 98% of the parent material, ensuring extremely high structural integrity.
Welding Precision And Control
TIG welding is known for its extremely high precision, capable of achieving weld tolerances within ±0.05mm, and is suitable for high-demand industries such as precision instrument and medical equipment manufacturing. For example:
- When welding 0.5mm thick stainless steel pipes, TIG welding can ensure that the weld strength reaches more than 95% of the parent material, and the heat affected zone (HAZ) is less than 0.1mm.
- When welding titanium alloy medical implants, after using TIG welding, the tensile strength of the weld reaches more than 900MPa, ensuring that no cracks or structural failure will occur after long-term implantation.
Typical Applications Of TIG Welding
Since TIG welding can provide spatter-free and high-precision welding quality, it is widely used in the following fields:
- Aerospace : Welding high-strength alloy materials, such as titanium alloys and nickel-based alloys. For example, in a certain aircraft engine fuel pipeline welding project, I used TIG welding to reduce the weld defect rate to less than 0.3%, meeting the reliability requirements under extreme working conditions.
- Medical Device Manufacturing : welding of stainless steel and titanium alloy implants, such as bone screws and joint implants. For example, when manufacturing titanium alloy heart stents, TIG welding ensures a 100% porosity-free weld structure and improves the biocompatibility of the product.
- Electronic Product Manufacturing : Suitable for precision welding of thin materials, such as stainless steel battery housings and aluminum alloy heat sinks. In a certain electronic product packaging project, TIG welding controls the heat-affected zone within 0.05mm to avoid damage to components caused by welding.
TIG welding has become an indispensable welding technology in the field of high-end manufacturing due to its excellent weld quality, precise control ability and wide material adaptability. Although TIG welding is slower and has higher operating requirements, it is irreplaceable in application scenarios that require high-precision, high-strength and beautiful welds.
Key Comparisons Of MIG vs. TIG Welding
When choosing welding technology, we need to make a comprehensive assessment from multiple dimensions, including welding strength, speed, applicable materials, weld aesthetics, and cost. MIG welding is known for its high efficiency and is suitable for mass production, especially in the automotive manufacturing, building structure, and sheet metal processing industries, while TIG welding has an advantage in the aerospace, medical equipment, and electronics industries due to its spatter-free, high-precision, and high-quality welds.
Below, I will combine data and actual application cases to deeply analyze the key comparisons of the two welding processes to help you choose the most suitable welding method :
Welding Strength
Welding strength directly affects the service life and structural stability of the product. In different application scenarios, the strength performance of MIG and TIG welding is different.
MIG Welding : MIG welds have high strength and are particularly suitable for thick plate materials . When using the spray transfer mode, the weld penetration can reach 5mm , and the weld strength can reach more than 90% of the parent material . However, due to the large molten pool of MIG welding and uneven cooling, micropores and pores may be generated inside the weld , reducing local strength. In the building steel structure, I have processed a batch of 8mm thick carbon steel components. The tensile strength test after MIG welding showed that the tensile strength of the weld reached 600MPa, which is equivalent to the performance of the parent material.
TIG Welding : TIG welding has a smaller molten pool and a more controllable heating area, so the weld is denser, the penetration depth is controllable, and the post-weld strength can reach almost 95% of the parent material . In the welding of titanium alloy medical devices, TIG welding can ensure that the weld is defect-free and has stable mechanical properties. For example, when welding titanium alloy (Ti-6Al-4V) implants, we obtained a weld with a tensile strength of more than 900MPa through TIG welding, which greatly improved the reliability of the implant.
Welding Speed
Welding speed determines production efficiency, which is one of the key factors determining manufacturing costs for large-scale production.
MIG Welding : MIG welding uses continuous wire feeding technology, and its welding speed is 2-5 times faster than TIG welding , which is suitable for mass production. For example, when welding 3mm thick stainless steel plates , the speed of MIG welding can reach 30cm/min , while TIG welding is only 5-10cm/min . In automobile manufacturing, I have participated in the optimization of body welding. After using MIG welding, the production line speed increased by 40% , significantly improving production capacity.
TIG Welding : TIG welding is slower, mainly because of the need to manually feed filler metal and lower heat input. For example, when welding 1mm thick stainless steel sheets, the TIG welding speed is about 10cm/min , but the weld quality is more uniform and suitable for high-precision manufacturing. Although the speed is slower, TIG welding is still the first choice in high-end manufacturing, such as aerospace parts welding.
Applicable Materials
Different metal materials have different requirements for welding methods. There are obvious differences in applicable materials between MIG welding and TIG welding.
MIG Welding : Suitable for materials with a thickness of more than 1mm , such as steel, aluminum, and nickel alloys. Due to the high heat input of MIG welding, it can quickly melt the parent material, so it performs well in welding low-carbon steel, stainless steel, and aluminum alloys . For example, when welding 6mm thick 6061 aluminum alloy , MIG welding can complete a one-meter long weld in 10 minutes , while TIG welding takes more than 30 minutes .
TIG Welding : Suitable for thin-walled materials of 0.5mm-5mm , especially for metals with high precision requirements such as stainless steel, aluminum alloy, titanium alloy , etc. For example, when welding titanium alloy (Ti-6Al-4V) parts, TIG welding can ensure that the heat-affected zone is less than 0.2mm , avoiding changes in the material structure. For aluminum-magnesium alloy parts in the aerospace field, TIG welding can achieve high-strength, pore-free welds that meet strict safety standards.
Weld Aesthetics
The cosmetic quality of welds is critical for products that require high visual impact, such as medical devices, electronics, and high-end industrial manufacturing.
MIG Welding : Due to the spatter that may be generated during the welding process, the welds usually require additional grinding and cleaning . For example, when welding stainless steel cabinets , MIG welding may produce spatter particles and require 30 minutes of additional processing time to polish the weld. However, in building steel structures and heavy equipment, the weld appearance is not required to be high , so MIG welding is still a more economical choice.
TIG Welding : The weld surface is smooth, almost spatter-free , and no additional grinding is required. When welding 3mm thick stainless steel medical device housings , the weld width of TIG welding can be controlled within 2mm , and it can be directly used for high-end products without subsequent treatment. For example, in the welding of electronic product housings, TIG welding can ensure uniform welds and meet the strict quality standards of high-end brands.
Cost Comparison
Welding costs mainly include equipment investment, material consumption, labor costs and subsequent processing costs.
MIG Welding : MIG welding equipment is relatively cheap, with entry-level MIG welding machines costing between $1,000 and $5,000 , while TIG welding machines are usually between $3,000 and $10,000 . In addition, the cost of welding wire for MIG welding is lower, with the price of stainless steel welding wire being about $5 to $8 per kilogram , and the overall cost being 30% to 50% lower than that of TIG welding . In large-scale production, the unit cost of MIG welding is significantly lower than that of TIG welding. For example, in automobile chassis welding , the production cost of MIG welding is about 35% lower than that of TIG welding .
TIG Welding : TIG welding machines are more expensive and require high-purity argon during the welding process, which increases operating costs. For example, when welding aluminum alloy aviation parts, the argon cost required for TIG welding is 20%-30% higher than that for MIG welding . In addition, TIG welding is slower and has higher labor costs. For example, it takes 40 minutes for TIG welding to weld a 1-meter-long stainless steel pipe , while MIG welding only takes 15 minutes , which will significantly affect the overall cost in mass production.
MIG welding and TIG welding each have their own advantages, and the choice of welding method should be based on the specific project requirements. If you are looking for efficient production and lower costs , MIG welding is an ideal choice for automotive manufacturing, building steel structures, and large-scale sheet metal processing. If you have higher requirements for welding quality, precision, and aesthetics , TIG welding is more suitable, such as aerospace, medical equipment, and high-end electronic product manufacturing. Reasonable selection of welding methods can improve production efficiency, reduce costs, and ensure product quality and reliability.
Application Scenarios Of MIG And TIG Welding
MIG welding and TIG welding are suitable for different application scenarios. MIG welding is widely used in mass production due to its high speed and easy operation , such as automobile manufacturing, building steel structure and sheet metal processing . TIG welding is known for its high precision and beautiful welds , and is suitable for aerospace, medical equipment manufacturing and electronics industries , which require strict control of weld quality and aesthetics.
Best Applications For MIG Welding
- Automobile Manufacturing : MIG welding is widely used in automobile bodies, chassis and frame structures. For example, in the welding of 1.5mm thick automobile steel plates , the production speed of MIG welding is 3-5 times faster than that of TIG welding , which significantly improves production efficiency and meets the needs of large-scale assembly.
- Sheet Metal Processing : Suitable for welding steel plates with a thickness of 2mm~10mm . In the manufacture of industrial equipment shells, MIG welding can maintain a relatively fast welding speed while ensuring that the weld strength reaches 450-600MPa to meet the load-bearing requirements.
- Construction And Heavy Industry : MIG welding is widely used in industries such as bridges, steel structure buildings, and heavy machinery . In steel structure construction, MIG welding can reduce construction time by 30% , improve production efficiency , and ensure structural stability.
Best Applications For TIG Welding
- Aerospace : TIG welding is used to weld high-performance materials such as titanium alloy, aluminum alloy, stainless steel, , with a tolerance control within **±0.05mm**. For example, in the welding of aircraft engine parts, TIG welding can ensure the density of the weld to reach 99.9% , avoid cracks, and improve flight safety.
- Medical Equipment Manufacturing : Medical devices have extremely high requirements for welding quality. For example, the welds of titanium alloy implants must be crack-free and pollution-free . TIG welding uses high-purity argon gas , which can reduce welding pollution to less than 0.1% , ensuring the safety and durability of medical devices.
- Electronics Industry : TIG welding is widely used in precision electronic components, thin-walled stainless steel structures, lithium battery packaging and other fields. In the manufacture of electronic equipment, TIG welding can control the heat affected zone (HAZ) to less than 0.2mm , avoid deformation of parts and improve assembly accuracy.
| Parameter | MIG Welding | TIG Welding | |
| Applicable Industries | Automobile manufacturing, sheet metal processing, building steel structure | Aerospace, medical devices, electronics manufacturing | |
| Welding Speed | Fast, suitable for mass production, 2-5 times faster than TIG | Slow, suitable for high precision welding | |
| Welding Accuracy | Generally, suitable for tolerances above ±0.5mm | High, up to ±0.05mm | |
| Material Thickness | Carbon steel, stainless steel, aluminum alloy above 1mm | Aluminum alloy, titanium alloy, stainless steel above 0.5mm | |
| Welding Seam Aesthetics | May need sanding, there is splatter | The weld is smooth and spatter-free, no additional processing is required | |
| Production costs | Low, low equipment cost, low welding wire cost | High, expensive equipment, and time-consuming welding process | |
| Heat Affected Zone | Larger, about 0.5-2mm | Small, usually less than 0.2mm | |
| Applicable Parts | Frame, steel structure, thick plate welding | Aviation parts, medical equipment, precision welding | |
| Weld Strength | Suitable for load-bearing structures, but may have porosity defects | The weld has high density and the tensile strength can reach more than 95% of the parent material | |
MIG welding and TIG welding have their own advantages in different fields. In large-volume, high-efficiency welding tasks such as automotive manufacturing, steel structures, and sheet metal processing , MIG welding has more advantages due to its fast, efficient, and low- cost characteristics. For industries with high precision and high quality requirements , such as aerospace, medical equipment, and electronic manufacturing , TIG welding provides higher weld quality and consistency. Reasonable selection of welding processes can not only improve production efficiency, but also effectively reduce costs and ensure that products meet industry standards and customer needs.
How To Choose The Appropriate Welding Method
When choosing MIG welding or TIG welding, we need to weigh key factors such as production requirements, welding accuracy, material properties, production efficiency and cost . MIG welding is suitable for mass production due to its high productivity and low cost , while TIG welding is more suitable for demanding precision manufacturing due to its high accuracy and beautiful welds .
When To Choose MIG Welding
- Production Efficiency Is Crucial : MIG welding is 2-5 times faster than TIG welding , and is suitable for mass production scenarios such as automotive manufacturing, heavy industry and sheet metal processing . For example, in the welding of 2mm thick carbon steel plates , the deposition rate of MIG welding can reach 8-12kg/h , while TIG welding is only 1-2kg/h , which significantly improves production efficiency.
- Welding Metals With AThickness Greater Than 1mm : MIG welding is suitable for steel, stainless steel, aluminum alloys and nickel alloys with a thickness greater than 1mm . In the welding of bridge structures in the construction industry , the penetration depth of MIG welding can reach more than 5mm , ensuring the stability of the steel structure.
- Lower Production Costs : MIG welding equipment has a lower purchase cost . For example, an entry-level MIG welder costs about $2,000-5,000 , while a TIG welder of the same level may cost as much as $8,000-15,000 . In addition, the cost of MIG welding wire is about 30%-50% lower than that of TIG welding filler materials , making it suitable for companies with limited budgets.
When To Choose TIG Welding
- Extremely High Welding Precision Requirements : In high-end industries such as aerospace and medical equipment manufacturing, TIG welding ensures high-precision welding because its tolerance is controlled within ±0.05mm . For example, in the manufacturing of titanium alloy aviation parts , the tensile strength of TIG welded welds can reach more than 95% of the parent material , effectively improving the durability of parts.
- Applicable To Thin-Walled Materials (0.5mm-5mm) : TIG welding is particularly suitable for thin-walled structures such as aluminum alloy, titanium alloy, stainless steel , such as medical implants, electronic components, etc. In the welding of 0.8mm thick stainless steel sheets , TIG welding can control heat input, avoid deformation, and keep the weld smooth and crack-free .
- High Requirements For Weld Aesthetics : TIG welding can form spatter-free, uniform and smooth welds, which are suitable for high-end product manufacturing . For example, in the welding of luxury car exhaust pipes , TIG welding can provide mirror-grade welds without additional grinding, improving the visual aesthetics of the product.
Whether to choose MIG welding or TIG welding depends on your specific production needs, material properties and budget . If you are pursuing efficient production, welding thick plates and are cost-sensitive , MIG welding is a better choice. If you need extreme precision, welding thin-walled materials, and have high requirements for weld beauty , TIG welding is undoubtedly more advantageous. In my actual projects, I usually flexibly adjust the welding process according to customer needs and product characteristics to ensure the best balance of quality, cost and efficiency.
FAQs
Is TIG Or MIG Welding Better?
The choice between TIG and MIG welding depends on the application. TIG welding provides higher precision and aesthetic welds , suitable for thin materials (0.5-5mm) with ±0.05mm tolerance . MIG welding is 2-5 times faster , ideal for thicker metals (>1mm) and high-volume production . In my projects, I use TIG for aerospace parts and MIG for automotive components due to efficiency and cost considerations.
Is A Beginner Welder MIG Or TIG?
For beginners, MIG welding is easier to learn due to its semi-automatic wire feed , requiring only one-hand operation . It provides faster welds and is more forgiving with inconsistent torch movement . TIG welding , in contrast, requires both hands and a foot pedal , making it more challenging . In my experience, most entry-level welders master MIG within days , whereas TIG takes months to develop consistent weld quality.
Can You TIG Weld Without Gas?
No, TIG welding requires an inert shielding gas to protect the weld from oxidation and contamination. Pure argon is the standard choice for TIG, as using no gas would result in porosity, oxidation, and weak welds . In one of my projects, improper gas flow during titanium welding led to surface oxidation, reducing weld strength by 30% , requiring rework and cost overruns .
Does MIG And TIG Welding Use The Same Gas?
Not always. MIG welding typically uses a 75% argon + 25% CO₂ mix for steel , while TIG welding requires 100% argon to prevent contamination. In aluminum welding , both MIG and TIG use pure argon , but helium blends are sometimes added for deeper penetration. In my aerospace projects , using CO₂ with TIG caused excessive tungsten erosion, highlighting the importance of selecting the correct gas.
What Happens If You TIG Weld With MIG Gas?
Using MIG gas (argon + CO₂) for TIG welding can lead to oxidation, poor arc stability, and electrode contamination . CO₂ promotes oxidation , reducing weld quality, especially in stainless steel and aluminum . In my tests, welding 304 stainless steel with 75/25 gas mix resulted in excessive spatter and weld discoloration , compromising both strength and appearance. Always use 100% argon for TIG.
What Type Of Gas Is Best For MIG Welding?
The best gas depends on the material. 75% argon + 25% CO₂ is ideal for mild steel , balancing penetration, spatter control, and cost . 100% CO₂ increases penetration but produces more spatter . Pure argon is used for aluminum and non-ferrous metals , while helium-argon mixes improve heat transfer. In my production , switching to a 90% argon, 10% CO₂ blend for stainless steel reduced oxidation and improved bead appearance by 25% .
Conclusion
MIG welding and TIG welding each have their own advantages, and the choice depends on the project requirements. MIG welding is suitable for mass production and thick metal welding. It is low cost and fast, and is the preferred choice for automotive manufacturing and sheet metal processing. TIG welding is suitable for high-precision, thin material welding, providing higher quality welds, and is suitable for industries such as medical and aviation. In our CNC manufacturing projects, the optimal welding method should be selected based on factors such as precision requirements, production costs, and material thickness to improve production efficiency and product quality.