What Is the Difference Between MIG and TIG Welding?

You can use tungsten inert gas (TIG) and metal inert gas (MIG) welding to make high-quality joints between different types of metal. Neither option is superior overall, but the unique welding techniques and processes will suit different jobs better. 

MIG welding is generally less complex and penetrates thicker materials more effectively, whereas TIG welding is ideal for precise welds on thinner materials. Explore the similarities and differences between MIG and TIG welding and when to use each type. 

TIG vs. MIG Welding

TIG and MIG welding techniques are similar, but have key distinctions to be aware of before choosing one over the other. Important differences include: 

• Cost: MIG welding is faster, so it can be more cost-effective in terms of labor costs and productivity. The machines, parts and the wire required for MIG welding are usually easier to source and less expensive than TIG parts.
• Process: While both use arc welding, the process is different, and you need specific welding equipment and tools for each type. This includes the electrodes used, the need for separate welding rods, foot pumps and power sources. 
• Weld strength: TIG welds can be stronger because they use a narrower arc for better penetration into the metals. They can also be tougher because they can have fewer defects.
• Application: TIG welds use a handheld filler rod, which allows for more accurate joins. However, this means using two hands and a foot pedal. This makes TIG welds better for workbenches and static setups, whereas MIG welding gives you a free hand for awkward joins or for site work.
• Ease of use: MIG welding is easier to learn, partly because less equipment is needed, and one hand is always free. 
• Precision and aesthetics: For fewer spatters or discolorations, choose TIG welding for less cleanup work. MIG welds can still be done carefully to preserve aesthetics, and you can polish up any blemishes after welding. 
• Automation: MIG torches or guns are often compared to hot glue guns, have an automatic arc and can be run continuously. TIG welding requires operators to adjust the amperage to control the heat needed to melt materials.
• Gas flow: Depending on the materials, TIG welding can use a lower gas flow rate than MIG welding.
• Power source: MIG techniques use direct current (DC) power for stability and can penetrate most metals. TIG can use alternating current (AC) or DC power to suit the type of metals, electric arc and weld pool spatter.

MIG and TIG welding both follow a similar process to arc welding. This involves an electric arc or current that heats up and melts the metals or base materials you want to join together. You can also use filler materials in both MIG and TIG welding to help strengthen the bonds. 

Heating the base materials and filler creates a pool of molten material, which then cools to form a solid, clean joint. The shielding gas protects materials from contamination or oxidation. Both types of welding can be used across different industries, from manufacturing and construction to aerospace and marine.

TIG Welding Process

TIG welding, also known as gas tungsten arc welding (GTAW), uses a non-consumable tungsten electrode to heat up and melt the parent materials and filler materials used to create a joint. 

The foot pedal controls the heat by setting the correct amperage for the materials you’re working on. With the welding electrode in one hand, add the filler material with the other using a welding rod placed into the welding pool. 

The best practice is to use argon as the shielding gas, as it is the most affordable and accessible of inert gases. Argon protects your weld from defects caused by oxygen and nitrogen contamination. 

Benefits and Applications of TIG Welding

TIG welding can be more effective for some applications, including:

• Thin metals: TIG welding can be less aggressive on thinner gauge metals, which helps prevent warping or burning through the material. It is also possible to make autogenous welds with no need for filler material. You can use a lap joint weld to join the parent materials together.
• Exposed beads: TIG welding can give a better finish for cleaner, more aesthetic welds. This is useful for consumer products or when beads are exposed.
• Ferrous and nonferrous Metals: Typically, TIG welds join steels and nonferrous metals, such as aluminum and copper. 
• Workshop welding: Outdoor windy conditions can interfere with TIG welds. Instead, TIG welding is better for precision jobs in a workshop environment where the control of the filler rod and foot pedal is more beneficial. 

MIG Welding Process

Also known as gas metal arc welding (GMAW) or wire welding, MIG welding uses a consumable solid wire electrode. The wire acts as both the electrode and the filler material here. Constantly feed the spool of wire through the welding gun into the weld pool, where it is heated, melting the parent material and adding a filler material to help join them together.

You can also use argon as a shield gas for MIG welding, with the option to add carbon dioxide. The added CO2 prevents oxidation and allows for short arc transfer or dip transfer welding, which allows for welding in various positions. 

Benefits and Applications of MIG Welding

MIG welding offers many benefits, including the following:

• Suitability for diverse operations: MIG techniques are suited to a wide range of materials, thicknesses and welding positions for when you need versatility in your welding operations. 
• Covered welds: When aesthetics are less important, such as in structural applications, MIG welds are durable, and you can paint or cover them if needed.  
• Quick production times: MIG welding is efficient and often faster than TIG welding, so you can reduce lead times and labor costs. 
• Thicker materials: MIG welding can handle different thicknesses and gauges, but it is more effective for welding thicker materials. This is because MIG offers higher deposition rates and deeper penetration into the materials.
• Training new hires: MIG welding is less complex to learn, making it easier for beginner welders to create acceptable welds while maintaining production speed.

Get Started With Meritus Gas Partners Today

Making the right investment when choosing welding equipment depends on your unique welding operations. MIG or TIG welding are both good options for creating quality, lasting welds. However, their key differences do set them apart for some applications.

For personalized welding advice, work with an expert at Meritus Gas Partners. Our network of independently run welding supply and industrial gas distributors offers you a service you can depend on for your essential equipment. Contact us to get started today! 

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