Plasma vs. TIG Welding

Differences and Applications

Plasma and TIG welding are both precise arc welding processes, but they differ significantly in terms of energy density, speed, and typical applications. Schnelldorfer Maschinenbau highlights the strengths of both processes and takes a closer look at the topic of plasma vs. TIG welding: differences and applications.

 

How does TIG welding work?

TIG welding, short for tungsten inert gas welding, creates a cone-shaped arc between a non-consumable tungsten electrode and the workpiece. An inert shielding gas, such as argon or helium, shields the molten pool from oxygen, thereby ensuring high weld quality.

 

This makes the TIG process one of the arc welding processes. Its use requires a great deal of skill and practice, as the welder must maintain a constant distance between the electrode and the workpiece throughout the entire welding process. When welding aluminum and other light metals, the welder also uses alternating current to break through the oxide layer. In this case, the filler material is fed separately via welding rods. TIG welding delivers outstanding weld quality, especially on thin sheets.

 

How does plasma welding work?

Plasma welding constricts the arc through a water-cooled copper nozzle and focuses it into a concentrated plasma beam. This results in a higher energy density than in TIG welding, enabling narrower and deeper welds in a single welding process.

 

The plasma gas—usually argon—flows through the nozzle and reaches very high temperatures in the plasma jet. The plasma torch itself is larger than a TIG torch. Due to the higher energy density of the confined arc, the process is also suitable for thicker materials. One advantage is that plasma welding requires up to 30 percent less filler material, allows for precise control of welding parameters, and integrates well with automation. A pilot arc handles the ignition and stabilizes the welding process even at low current levels.

 

This is how TIG and plasma welding differ

TIG and plasma welding differ primarily in terms of arc guidance, energy density, and welding speed. The conical TIG arc burns openly and steadily, while the constricted plasma jet is more concentrated, penetrates deeper, and, depending on the application, achieves significantly higher welding speeds.

 

A Direct Comparison of TIG and Plasma Welding

 

Characteristic	TIG Welding	Plasma welding
Arc	cone-shaped, open	tight, focused
Energy density	medium	higher
Weld	wider	narrower and deeper
Welding speed	lower	up to 100 % higher
Filler material	more	up to 30 % less

 

Autogenous Welding Compared to TIG and Plasma Welding

Oxy-fuel welding joins metals using a fuel gas-oxygen flame instead of an electric arc, thereby reaching significantly lower temperatures than TIG or plasma welding. Because of these characteristics, oxy-fuel welding is particularly well-suited for repair work and thin sheet metal, but it falls short in terms of weld quality compared to other welding processes.

 

In oxy-fuel welding, the welder feeds the filler material using welding rods; a shielding gas atmosphere, as used in TIG welding, is not required at all. This makes the process versatile, but it is less controllable when very clean, reproducible, or high-strength welds are required. In addition, the wide flame introduces more heat into the component, which can cause thin or delicate workpieces to warp more easily. For precise, high-load welded joints, manufacturing companies therefore tend to opt for tungsten inert gas (TIG) welding or plasma welding, because the arc, heat input, and welding parameters can be controlled much more precisely with these methods.

 

MAG Welding—the Better Alternative? 

Metal-Active Gas (MAG) welding uses a consumable welding electrode and an active shielding gas, and is particularly well-suited for steel in heavy-duty metalworking. Along with the MIG process, MAG stands out for its high deposition rate and speed when working with thicker materials.

 

Although MAG welding does not achieve the precision of TIG or plasma welding, it compensates for this with very high productivity, especially when steel components are produced in series. In addition, MAG welding lends itself well to automation and remains cost-effective even for longer welds, load-bearing structures, or repetitive welding tasks. Because the welding wire is fed continuously, this process offers high deposition rates and short cycle times. However, MAG is not necessarily the better alternative in all cases; rather, it is the better choice when speed, cost-effectiveness, and robust steel joints are more important than the finest weld appearance and maximum precision.

 

Typical Applications for Plasma and TIG Welding

Plasma and TIG welding are used wherever weld quality and precision take precedence over speed. TIG welding is the method of choice for high-precision welding on thin workpieces, while plasma welding is used for thicker materials, nickel-based alloys, and automated welding applications.

 

Welding processes are used most frequently in these five industries: 

 

• Aerospace: For the highest quality in safety-critical components, often made of titanium
• Automotive Industry: For Reproducible Welded Joints in Mass Production
• Medical Technology: For surgical instruments made of stainless steel with extremely fine geometries
• Shipbuilding: For corrosion-resistant welds on steel and stainless steel
• Electronics Industry: For the Tiniest Seams on Sensitive Components

 

Plasma and TIG Welding with Schnelldorfer Maschinenbau

Schnelldorfer Maschinenbau, based in Schnelldorf, Bavaria, has been developing welding machines for TIG, plasma, MIG/MAG, and laser welding for over 40 years. Our experts tailor each system to your materials, welding parameters, and level of automation—from seam preparation through to documented production. Thanks to this modular design, you get the system you truly need.

 

Contact us today, and let’s work together to find the welding process that’s right for your production. We look forward to hearing from you!

 

Frequently asked questions (FAQ)

When is plasma welding a good choice?

Plasma welding is beneficial for thicker materials, automated processes, and high-volume production. It achieves a higher energy density and often significantly higher welding speeds than other welding processes, such as TIG welding.

 

Can plasma welding also be used to process nickel-based alloys?

Yes, plasma welding is also suitable for processing nickel-based alloys, which are often used in demanding industrial applications.

 

Is TIG welding cheaper than plasma welding?

Yes, TIG systems are generally less expensive to purchase than plasma systems, which reduces investment costs. However, plasma welding often offsets this through its advantages in productivity and automation.