Arc welding is a key process used to join metals by using an electric arc to melt the materials at the joint. With different types of arc welding available, each has its strengths and is suited for specific jobs. In this article, we’ll cover the five most common types of arc welding, explain how they work, and give you real-world examples of where they’re used. Whether you’re buying an arc welding machine for the first time or deciding which process is right for your job, this guide will help you understand your options.
What Is Arc Welding?
Arc welding is a technique that uses an electric arc to generate intense heat, which melts metal at the welding point. The arc is created between a welding electrode and the base metal. This process is used in many industries like construction, manufacturing, and even aerospace. The welding machine controls the arc, ensuring that the right temperature and energy are applied to create strong, lasting welds.
Arc welding machines are designed to supply the necessary electrical power for different types of welding. These machines can run on either AC (alternating current) or DC (direct current), depending on the welding process being used.
1. Shielded Metal Arc Welding (SMAW / Stick Welding)
This is one of the most traditional types of arc welding, also known as stick welding. It uses a coated electrode to create the arc, and the electrode itself melts to fill the joint.
Where is it used?
- Construction: Building steel frames and structures like bridges and towers.
- Repairs: Great for fixing metal parts, especially in outdoor environments.
- Pipelines: Commonly used in pipe installations, even in windy or rough conditions.
Advantages:
- Portable: You can carry the machine around easily, which makes it perfect for outdoor work.
- Cost-Effective: The equipment is relatively affordable, making it a go-to option for many projects.
- Wind Resistance: Unlike other methods, SMAW works well outdoors in windy conditions.
Limitations:
- Slow Speed: It’s slower compared to some other welding methods, so it’s not ideal for high-speed production.
- Slag Cleanup: After welding, you need to remove the slag (the leftover material from the electrode), which can take extra time.
2. Gas Metal Arc Welding (GMAW / MIG Welding)
Gas Metal Arc Welding (GMAW), or MIG welding, uses a continuously fed wire electrode that melts to create a joint. The process is shielded by a flow of gas (usually a mix of argon and CO2), which protects the weld pool from contamination.
Where is it used?
- Automotive Industry: Fast welding of car bodies and parts in production lines.
- Manufacturing: Common in factories for large-scale metal production.
- Sheet Metal: Used for welding thin metals, like in appliances or metal furniture.
Advantages:
- Fast: The process is much quicker than SMAW, allowing for faster production rates.
- Less Cleanup: There’s less spatter, which makes cleanup easier compared to other methods.
- Easy to Learn: MIG welding is often easier for beginners to pick up compared to some other welding types.
Limitations:
- Outdoor Use Limitations: The gas shield can be blown away by wind, so it’s best used indoors or in a controlled environment.
- Equipment Cost: While the process is faster, the welding machine and gas cylinders can increase costs.
3. Gas Tungsten Arc Welding (GTAW / TIG Welding)
Gas Tungsten Arc Welding (GTAW), or TIG welding, uses a non-consumable tungsten electrode to create the arc. The process is highly precise, and the welder must manually feed a filler material to the joint.
Where is it used?
- Aerospace: TIG welding is often used to weld high-strength metals like titanium for aircraft.
- Automotive and Racing: Ideal for precision welding of lightweight metals such as aluminum and stainless steel.
- Art and Jewelry: The fine, clean welds produced by TIG are great for decorative work.
Advantages:
- Precision: Provides clean, precise welds with excellent control, perfect for delicate materials.
- Clean Welds: TIG welding produces a minimal amount of spatter, creating visually pleasing, high-quality welds.
- Wide Material Compatibility: Works well with a variety of metals, including aluminum, stainless steel, and more.
Limitations:
- Slow Process: It takes more time than MIG or SMAW welding, so it’s not the best choice for high-speed production.
- Requires Skill: TIG welding requires a higher level of expertise and a steady hand to achieve good results.
- Expensive Equipment: The machines and materials can be more expensive than other types of welding.
4. Flux-Cored Arc Welding (FCAW)
Flux-Cored Arc Welding (FCAW) is similar to MIG welding, but instead of using a solid wire electrode, it uses a flux-cored wire. This provides its own shielding, which is why it’s often used for welding outdoors.
Where is it used?
- Construction: Common in construction for welding thick steel beams and parts.
- Shipbuilding: FCAW is used in the heavy-duty shipbuilding industry, where strong welds are needed.
- Cranes and Heavy Equipment: It’s often used in the construction of large machinery and vehicles.
Advantages:
- Wind-Resistant: FCAW works well outdoors, even in windy conditions.
- High Welding Speed: It’s faster than SMAW, producing more welds in less time.
- Stronger Welds: Produces stronger joints, especially when welding thick materials.
Limitations:
- More Smoke and Fumes: The flux core produces more fumes, which require good ventilation.
- Higher Wire Cost: Flux-cored wire is more expensive than solid MIG wire.
5. Submerged Arc Welding (SAW)
Submerged Arc Welding (SAW) is an automatic or semi-automatic process where a continuous wire electrode is fed under a blanket of flux, keeping the weld pool clean and protected. It’s commonly used for large-scale, high-volume production.
Where is it used?
- Shipbuilding: Widely used for welding thick steel plates in shipyards.
- Pressure Vessels: Used for welding heavy-duty pressure vessels and large containers.
- Heavy Machinery: Common in manufacturing large, durable parts for industrial machines.
Advantages:
- High-Volume Welding: This method is incredibly efficient, capable of welding large volumes of material in a short time.
- Minimal Defects: SAW creates very few defects in the weld, making it ideal for high-quality production.
- Deep Penetration: Ideal for welding thick materials, with deep penetration that ensures strong joints.
Limitations:
- Indoor Use Only: The process creates a lot of flux dust, so it’s best suited for indoor environments.
- Large Equipment: The machines are bulky and stationary, so they’re not ideal for portable or fieldwork.
Comparison of the 5 Most Common Types of Arc Welding
| Welding Type | Best For | Advantages | Limitations |
| SMAW (Stick Welding) | General-purpose welding, outdoor work | Portable, cost-effective, works in wind, versatile | Slow speed, requires slag cleanup, not ideal for high-speed production |
| GMAW / MIG Welding | Automotive, manufacturing, sheet metal | Fast, easy to learn, less cleanup, suitable for factory settings | Limited outdoor use due to gas shielding, higher equipment cost |
| GTAW / TIG Welding | Aerospace, high-precision jobs, art | High precision, clean welds, works with many metals | Slow process, requires skill, expensive equipment |
| FCAW (Flux-Cored Arc Welding) | Heavy-duty work, shipbuilding, outdoor welding | Wind-resistant, fast welding speed, strong welds for thick materials | More fumes, higher wire cost |
| SAW (Submerged Arc Welding) | Large industrial projects, shipbuilding | High-volume welding, minimal defects, deep penetration for thick materials | Indoor use only, requires large equipment |
How to Choose the Right Arc Welding Process and Machine
Choosing the right arc welding process depends on factors such as the material, environment, and desired results. Here’s a quick guide:
1. For Outdoor Work or Heavy Materials: FCAW or SMAW
- FCAW (Flux-Cored Arc Welding) is ideal for outdoor work and thick materials like steel. It’s more resistant to wind and offers strong, efficient welds.
- SMAW (Stick Welding) is portable and suitable for tough conditions, especially for general repairs or welding rusty surfaces.
2. For Precise, High-Quality Welds: TIG Welding
TIG Welding is perfect for precise and clean welds on thin materials like stainless steel or aluminum, where high-quality results are essential.
3. For Fast, High-Volume Welding: MIG Welding and SAW
- MIG Welding is excellent for faster, continuous welding, especially on mild steel in factory settings.
- SAW (Submerged Arc Welding) is best for large, industrial projects that require deep penetration and high weld strength.
4. Machine Selection
Conclusion
The five most common types of arc welding—SMAW, MIG, TIG, FCAW, and SAW—each have their unique advantages and are suited for different welding needs. Whether you’re building a skyscraper, working on a car, or making precise aerospace parts, understanding the strengths of each method will help you choose the right one for your project.
FAQs About Arc Welding
What are the safety risks of arc welding?
Arc welding poses several safety risks, including:
- UV Radiation: The intense UV light emitted by the welding arc can cause burns to the skin and eyes (welder’s flash). Always wear a helmet with the proper shading and protective clothing to shield yourself from UV rays.
- Electric Shock: Since welding machines use high voltage, there is a risk of electric shock. Always use insulated gloves and boots, and ensure the equipment is properly grounded.
- Fumes and Gases: Welding generates fumes that can be hazardous when inhaled. Always work in a well-ventilated area or use a fume extractor to avoid inhaling harmful gases like carbon monoxide and ozone.
How do I prevent defects in my welds?
To prevent defects in welds, consider the following tips:
- Ensure the workpiece is clean before welding. Any dirt, rust, or oil can cause defects.
- Use the correct settings for your welding machine (current, voltage, and speed).
- Maintain the correct distance between the electrode and the workpiece to avoid too much spatter or poor penetration.
- Use the right filler material for the metals being welded.
- Practice consistent motion while welding to avoid uneven welds.
Can I weld different types of metals together?
Yes, but it depends on the metals involved. Some metals, like stainless steel and carbon steel, can be welded together, though they may require special filler materials or processes. Always consult a welding guide or expert to determine the best method and filler for welding dissimilar metals to ensure strong and durable welds.
