What Gases Are Used in Metal Fabrication?

Metal fabrication relies on several industrial gases, with argon, helium, carbon dioxide, and oxygen being the most commonly used options for various welding and cutting processes.

In this guide, we’ll discuss these gases in more detail to show you their roles in metal fabrication. We’ll then explore some common gas mixtures for when a single gas isn’t enough, after which you’ll learn about the best practices for selecting the right gas or mixture. 

Understanding Shielding Gases and Their Critical Role

Shielding gases are a must for successful metal fabrication. They create a protective environment around the weld area, keeping atmospheric gases from contaminating the weld to ensure the right weld appearance and quality.

These gases aren’t just protective – they also influence:

• Arc temperature
• Weld penetration depth
• Final weld appearance

With this in mind, getting the right gas mix can mean the difference between a perfect weld and one that needs fixing.

Primary Gases Used in Metal Fabrication

Argon is the most widely used shielding gas in metal fabrication, especially for TIG and MIG welding. It’s like the Swiss Army knife of welding gases – versatile and reliable for most metals.

For aluminum and stainless steel work, pure argon is often your best bet. It provides excellent arc stability and helps prevent issues like spatter and porosity.

Other common gases include:

• Carbon dioxide (CO2): a popular heavy hitter commonly used for welding steel. While it’s not as refined as argon, it’s cost-effective and gives you deep penetration on thick materials.
• Helium: comes into play when you need extra heat, especially with thick aluminum or copper. It’s often mixed with argon to get the best of both worlds – argon’s stability with helium’s heat input.
• Oxygen: while not used alone, oxygen is crucial in gas mixtures. Adding a small amount of oxygen to argon can improve weld pool fluidity and help you get better fusion.

Gas Mixtures for Specific Applications

Different metals need different gas combinations, so there’s no one-size-fits-all solution. For mild steel, many fabricators use a mix of 75% argon and 25% CO2 to balance the cost, quality, and performance.

Stainless steel typically calls for a tri-mix of helium, argon, and CO2. This combination helps prevent chromium oxidation while providing good penetration and arc stability.

When working with aluminum, a mix of 75% helium and 25% argon is popular for thicker materials. The helium brings the heat, while the argon ensures stability.

Some specialized applications might need unique gas blends. For instance, exotic metals might require ultra-high purity argon or special mixtures to prevent contamination.

Best Practices for Gas Selection

Choosing the right gas starts with knowing your material and process. The most important factors to consider are:

• Material thickness
• Welding position
• Desired weld appearance

Cost matters too. While pure argon might give you the best results, a mix with CO2 could save money without sacrificing too much quality.

Contrary to popular belief, more expensive isn’t always better. Sometimes, a simple gas mix will do the job just fine. Focus on what works for your specific application.

Weather conditions and ventilation can affect your gas choice too. In outdoor applications, you might need to adjust your mixture or flow rate to compensate for wind and temperature changes.

Keep in mind that proper gas flow rates are just as important as choosing the right gas. Too much or too little flow can cause problems, even with the perfect gas choice.

Regardless of your chosen option, make sure to properly maintain your gas delivery system. Even the best gas won’t perform well if your regulators, hoses, or fittings are worn or damaged.

Ensure Perfect Welds With the Right Gas

Now that you understand the fundamentals of welding gases, you can make informed decisions that improve your fabrication quality and efficiency. Whether you’re working with standard steel or specialized materials, having the right gas makes all the difference.

After choosing your preferred option, make sure to buy it from a reputable supplier. Partnering with the right vendor ensures a consistent delivery of high-quality options that will support your projects and get you the results you’re looking for.