Cutting Metal with a TIG Welder: Benefits & Drawbacks

When I asked one of my pals, who has been into TIG welding for a decade now, if it is possible to cut metals with a TIG welder! He frowned and asked, “Are you crazy?” But then, he gave me a quick answer with some warnings. After that, I did my research and finally came to understand if one can use a TIG welder as a plasma cutter. This is what I found.

You can use a TIG machine to cut metal, but the cuts won’t be as good as plasma cut pieces. Gather 1/8″ electrode with sharpened tip, #3 or #4 cup, and argon. Set your flow meter to max and amperage to 250. Then, drag the cup fast but carefully to ensure consistency.

In this article, I’ll expand my answer to turn it into understandable details, so you can apply the techniques in real-life situations. However, I think you should start by knowing how TIG welding differs from plasma cutting. Only then, the whole process will seem easy.

Fundamental Differences Between TIG Welding and Plasma Cutting

Simply put, the difference is huge. In fact, one process (welding) joins metals while the other (plasma) cuts them. Since you’re thinking about doing the cutting with a TIG torch instead of a plasma cutter, I think I should fill you in on some details as to where both processes can produce the similar result.

TIG welding is a particular welding process that requires the operators to use both hands. Use one of your hands to help develop the arc and the other to add some filler material as required. Despite being arguably the most difficult of all welding processes, TIG welding occurs in three straightforward steps.

A shielding gas, typically argon, is used in a way that it flows over your weld area to protect the weld from airborne contaminants or the air. The welding machine draws electric current which passes through the tungsten electrode, thereby creating a lot of heat along your weld arc. This heat causes metal like steel or aluminum to melt. As the operator, you’ll add the filler metal.

So, you see that welding with a TIG torch looks almost like using an oxy-acetylene torch to do the same. Let’s try to understand plasma cutting in a simple way.

If you can think of matter being into the common states, such as a solid state, a liquid state, and a gaseous state, plasma comes at four. In plasma cutting, hot plasma produced in the form of an accelerated jet cuts through any electrically conductive metal like stainless steel, aluminum, etc.

Can a TIG Welder Be Used As a Plasma Cutter?

Cutting Metal with a TIG Welder

You might be wondering where or how you’ll get the jet of plasma out of your TIG welding machine which is designed to join, not essentially cut anything. In practice, you can choose certain types of metal and make some decent cuts.

Should you need to get away with the unintended consequences of this unconventional cutting method, avoid picking up thick sheets, and more importantly, try to not expect the nice and clean cuts which you would get with a plasma system.

Understand the Benefits

To be honest, using a TIG welding machine to complete the task of a plasma cutter is more of a cost-saving pursuit than an undertaking where precision and quality matter. Let me clarify this very thought for you.

Some people don’t have to cut metals on a daily basis, and welding is their primary business. You might just happen to be one of them who can easily work with metal pieces avoiding precisely cut edges. This is one reason you can use a TIG machine in place of a plasma system.

With the above reality in mind, you may not be interested in getting a plasma cutter that might cost you well over a thousand bucks. Also, you may not have a grinder with some slitting wheels or a metal nibbler or shear.

Sometimes, the need for precise cuts can be outweighed by the cost of all these tools and appliances or the need for a quick cutting job. In a situation like this, you can’t go wrong by relying on a TIG machine which is already available at your workshop.

Beware of the Drawbacks

As I said that a TIG torch won’t help you achieve the same cut quality as a plasma cutter would, you’ll struggle with a few obvious issues. For example, metal thickness is an important factor to consider. You have to choose a steel, aluminum, or stainless steel sheet that is not thicker than 0.063 inch. Please be advised that the thinner gauge will be better.

Choosing a 16 gauge metal sheet, you can use a TIG torch and expect some decent cuts. Whether you choose anything thicker on purpose or for the sake of the project requirements, you should bring a more useful tool on the table.

Again, there is a catch when you need to cut stainless steel with a TIG machine. Aluminum is okay, but stainless steel requires you to take some grinding measures to prepare the metal’s cut edge for the job.

How to Use a TIG Welder As a Plasma Cutter to Cut Metal?

I guess I’ve told a lot to dissuade you from using a TIG machine on this particular occasion. However, my intention is to help you do the job, which is why I’ll be talking about the steps you need to take.

Gathering Tools and Supplies

You don’t need anything fancy for this project, but some essentials will make life easier for you in the process. Take a look at the list of required items.

  • Electrode (1/8″)
  • Argon (1 Standard Tank)
  • Flow Meter
  • A TIG Machine (250 Amps)
  • TIG Cup (#3/#4)

If you are a TIG welder, most of these items, especially the welding machine and argon, should be readily available at your workshop. If you don’t have one or some of them, you can get them from your favorite shop at a small cost.

Cutting Metal with a TIG Welder

The way I’m going to describe the process may look like some preparatory tasks. It is okay to see it that way. But you’ll also learn how to cut with a TIG torch.

TIG Cup

You should start with the TIG cup which must be a small one like I said #3 or #4. The problem with larger cup sizes is that the flow rate of the shielding gas, argon in this case, has to be increased. We’re going to set the flow meter to its maximum point, anyway.

Electrode and Gas

The electrode tip needs to be prepped. You should have it sharpened. Don’t make it look like a needle that is extremely sharp. Rather, keep it slightly blunt. Then, check your argon tank. You’ll need a full tank because the process requires a lot of this gas.

Machine Settings

I won’t go into the details of TIG machine settings as I assume that you already know how to adjust the settings before a welding project. In fact, the type of your TIG machine should be considered at first. Also, you can keep everything except the amperage from the settings for your last steel welding project.

Although I’ve seen many welders recommend that the amperage should be set at 200, I think you should use more amperage because it will help you produce better cuts and work faster. I would say 250 amps for a safe and optimal point. However, you don’t have to buy a brand-new TIG machine just because your existing one doesn’t have higher than 200 amps.

Foot Pedal and Torch Switch

Using a foot pedal alongside a regular TIG welding setup is pretty common. If you have one, you should set your machine up for all the amperage it can bring at once. An experienced user of the foot pedal may want to use it manually.

Should you have a torch switch, you need to locate the upslope time and turn it off because a burst of amps is all you need. This brings you to the actual cutting task.

The Cutting Action

With a little understanding of plasma cutting, you can do it. Just follow the instructions to use a plasma machine. As you need a guide, a straight edge should be clamped on the metal sheet. Drag your TIG cup along the line as fast as possible without losing consistency or outrunning your cut. These are simple tasks that you would do on a plasma cutting project.

Final Thoughts

Oh, I forgot to mention one thing. Maybe, you would take enough precautions, but I advise you to put on your welding gear like gloves, helmet, or glasses. I would like your attention to another thing.

Don’t drag the TIG cup too fast to lose your line along the metal sheet being cut. I won’t say you can follow my instructions and get quality cuts without a failure. For this job, a TIG welding machine won’t work as efficiently as a plasma cutter, but you can always use a TIG machine to cut metals and save money on a dedicated plasma setup when you don’t have frequent needs.

Got more questions on the same topic? Well, I would love to answer any question you might have about this particular process or another. Feel free to write to me.

Last Updated on December 1, 2020 by Gary Hargrave