What Metals Can a Plasma Cutter Cut?

What Metals Can a Plasma Cutter Cut

Plasma cutters are renowned for their ability to slice through metal with speed and precision.

However, not all metals are created equal when it comes to their compatibility with plasma cutting technology.

This article aims to shed light on the types of metals that are most conducive to plasma cutting, exploring factors like conductivity, thickness, and surface properties that influence a metal’s suitability for this process.

So, what metals can a plasma cutter cut? Plasma cutters are versatile tools capable of cutting a wide range of metals. The key factor that determines if a plasma cutter can cut a particular metal is its electrical conductivity.

  1. Mild Steel: One of the most commonly cut materials, mild steel is easy to cut with a plasma cutter due to its excellent conductivity and moderate thickness.
  2. Stainless Steel: Plasma cutters handle stainless steel well, often used in fabrication for its corrosion-resistant properties.
  3. Aluminum: While reflective, aluminum can be cut with a plasma cutter, especially with modern machines designed to handle the reflection and conductivity of aluminum.
  4. Brass and Copper: These metals are more challenging due to their high thermal conductivity and reflectivity but can be cut with more powerful plasma cutting systems.
  5. Alloy Steels: Various alloy steels can also be cut using plasma cutters, though the specific settings might need to be adjusted based on the alloying elements.
  6. Cast Iron: While tougher to cut due to its brittleness and potential for hard spots, cast iron can be cut with plasma systems, especially for rough cuts.

Whether you’re a seasoned fabricator or a curious newcomer, this guide will provide valuable insights into the versatile world of plasma cutting.

Metals Suitable for Plasma Cutting

Plasma cutting is a versatile method that can handle a wide range of metals. Understanding the properties, characteristics, and best practices for cutting each type of metal is crucial for successful outcomes.

Stainless Steel

Stainless steel is renowned for its corrosion resistance and durability. It contains chromium, which forms a protective oxide layer on its surface.

This metal is often classified into different series, such as 300 series (e.g., 304 and 316) and 400 series (e.g., 430). The exact properties may vary depending on the specific grade, but stainless steel is generally strong, tough, and non-reactive.

Stainless steel finds its place in various industries, including construction, automotive, kitchenware, and aerospace.

It’s commonly used for fabricating kitchen sinks, appliances, medical equipment, and architectural elements due to its attractive appearance and rust-resistant properties.

  • Use a lower amperage setting to prevent excessive heat buildup and warping.
  • Employ a fine-cutting nozzle for cleaner, more precise cuts.
  • Maintain a slow and steady cutting speed to achieve the desired results.
  • Consider using a water table or a specialized stainless steel cutting table to reduce dross and fumes.

Mild Steel

Mild steel, also known as low carbon steel, is one of the most common metals in the manufacturing industry. It is characterized by its relatively low carbon content, making it easy to work with. Mild steel is tough, ductile, and highly weldable.

This versatile metal is used in a wide range of applications, including construction, automotive manufacturing, and general fabrication. It’s often used for structural components, pipelines, machinery, and automotive body panels.

  • Mild steel can be cut with ease using a plasma cutter, but you should adjust the amperage and cutting speed according to the thickness of the material.
  • Maintain proper standoff distance (the gap between the nozzle and the metal) to ensure a clean cut and reduce dross.
  • Consider using a drag shield or standoff guide to maintain consistent distance during cutting.


Aluminum is known for its lightweight and corrosion-resistant properties. It’s a good conductor of electricity and heat. Aluminum alloys, such as 6061 and 5052, are commonly used in various industries.

Aluminum is widely used in aerospace, automotive, and construction industries. It’s used for manufacturing aircraft parts, car bodies, window frames, and kitchen utensils due to its lightweight and corrosion-resistant nature.

  • Aluminum has a higher thermal conductivity compared to steel, so it requires a higher amperage setting for efficient cutting.
  • Use a specialized nozzle and shielding gas suitable for aluminum cutting.
  • To prevent molten aluminum from adhering to the nozzle, use an anti-spatter spray or gel.

Copper and Brass

Copper and brass are metals known for their excellent electrical conductivity and attractive appearance. Copper is highly ductile and malleable, while brass is an alloy of copper and zinc.

  • Copper and brass are more conductive than steel or aluminum, so adjusting the plasma cutter settings is crucial.
  • A specialized nozzle and cutting gas mixture may be required for clean cuts.
  • Carefully control the heat to avoid melting or warping these softer metals.

Metals to Avoid with Plasma Cutters

While plasma cutters are incredibly versatile tools, not all metals are compatible with this cutting method.

One category of metals that you should generally avoid using a plasma cutter on is high carbon steels.

High Carbon Steels

High carbon steels, often referred to as tool steels or carbon tool steels, contain a significant percentage of carbon, typically above 0.60%.

This high carbon content gives them exceptional hardness and wear resistance, making them ideal for applications like cutting tools and blades.

However, this very hardness and carbon content make them unsuitable for plasma cutting.

The primary issue with high carbon steels is their ability to absorb and retain heat. When subjected to the intense heat of a plasma arc, these steels can become overheated and lose their temper.

This results in a loss of hardness and, more critically, a degradation of their cutting edge.

The rapid heating and cooling cycles inherent to plasma cutting can lead to warping, cracking, and the formation of unwanted heat-affected zones.

When working with high carbon steels, it’s advisable to explore alternative cutting methods that are better suited to the material’s properties. Some alternatives include:

  1. Oxy-Fuel Cutting: Oxy-fuel cutting is a reliable method for cutting high carbon steels. It uses a mixture of oxygen and a fuel gas (acetylene, propane, or natural gas) to create a high-temperature flame that melts through the metal. This method allows for precise cuts without adversely affecting the steel’s hardness.
  2. Abrasive Waterjet Cutting: Abrasive waterjet cutting employs a high-pressure stream of water mixed with abrasive particles to erode and cut through the material. This method is effective for high carbon steels and offers the advantage of minimal heat-affected zones.
  3. Cold Sawing: Cold saws use a circular blade with teeth to cut through metals at low temperatures. This method produces clean and precise cuts while preserving the steel’s hardness.

High carbon steels are not the only metals to exercise caution with when using a plasma cutter. Other metals and materials that are typically avoided due to various challenges include:

  • Cast Iron: Cast iron is brittle and prone to cracking when exposed to rapid temperature changes during plasma cutting. Oxy-fuel cutting or specialized cutting methods are preferred for cast iron.
  • Plastics and Non-Metallic Materials: Plasma cutting generates extremely high temperatures, which can lead to the release of toxic fumes when applied to plastics or non-metallic materials. These materials should be avoided altogether.
  • Materials with Reflective Surfaces: Highly reflective metals, such as copper and brass, can cause issues with the plasma cutter’s arc stability. Specialized nozzles and settings may be necessary for cutting these materials.

Advanced Techniques and Tips

You’ll want to explore advanced techniques and employ expert tips to achieve exceptional results and elevate your metalworking skills. Let’s dive into these nuances:

1. Fine-tuning the Plasma Cutter for Different Metals
Plasma cutters come with adjustable settings, including amperage, cutting speed, and gas flow rates. For different metals, fine-tuning these settings is crucial. Here’s how:
Amperage: Adjust the amperage to match the thickness of the metal. Higher amperage is needed for thicker materials, while lower amperage prevents excessive heat buildup on thinner metals.
Cutting Speed: Vary the cutting speed to achieve optimal results. Slower speeds provide more precision, while faster speeds are ideal for rough cuts.
Gas Selection: Different metals may require different gases or gas mixtures for optimal cutting. Consult your plasma cutter’s manual for recommended gases for specific metals.
2. Consumables and Their Impact on Cutting Quality
The consumables of a plasma cutter, including electrodes, nozzles, and shields, play a significant role in cutting quality. Here’s what you need to know:
Electrodes: Regularly inspect and replace electrodes to maintain a stable arc and clean cuts.
Nozzles: Nozzles wear out over time and can affect the cutting stream. Replace them as needed for consistent results.
Shields and Retaining Caps: These components protect the torch and should also be replaced when worn. Regular maintenance is key to quality cuts.
3. Recommended Thicknesses for Various Metals
Achieving the best results in plasma cutting involves understanding the ideal thicknesses for different metals. Here are some general guidelines:
Mild Steel: Plasma cutting is effective for mild steel up to approximately 1 inch (25 mm) in thickness.
Stainless Steel: Stainless steel up to 1 inch (25 mm) can be cut with precision using a plasma cutter.
Aluminum: Plasma cutting is suitable for aluminum up to 1 inch (25 mm) thick.
Copper and Brass: These softer metals can be cut effectively with a plasma cutter for thicknesses up to 0.5 inches (12 mm). Beyond this, other methods may be more suitable.
4. Troubleshooting Common Cutting Issues
Even with the best equipment and techniques, issues can arise during plasma cutting. Here are common problems and how to address them:
Excessive Dross: Adjusting the cutting speed, gas flow, or torch height can help reduce dross.
Warped Material: Ensure even heat distribution during cutting and use proper fixturing to prevent warping.
Inconsistent Cuts: Check consumables for wear and ensure they are correctly installed. Verify the gas supply for consistency.
Excessive Noise: Noise can indicate improper gas flow or a damaged torch. Investigate and address the source of the noise for smoother operation.


Plasma cutters offer a versatile and efficient solution for cutting a wide array of metals.

From everyday materials like mild steel and stainless steel to more challenging ones like brass, copper, and even cast iron, plasma cutters can handle a diverse range of metals, provided they are electrically conductive.

The key to successful cutting lies in understanding the properties of the metal at hand, as well as the capabilities and settings of your plasma cutter.

As technology advances, the potential of plasma cutters continues to grow, making them an indispensable tool for anyone involved in metal fabrication.

Knowing what metals your plasma cutter can handle is crucial for optimizing your work, ensuring safety, and achieving the best possible results.

Frequently Asked Questions

Can I use a plasma cutter to cut other materials like wood or plastic?

No, plasma cutters are designed specifically for cutting metals. Attempting to cut materials like wood or plastic with a plasma cutter can be dangerous and result in damage to the equipment.

What safety precautions should I take when using a plasma cutter?

Safety is paramount when working with a plasma cutter. Always wear appropriate PPE, ensure proper ventilation, and follow manufacturer guidelines for safe operation. Additionally, have a fire extinguisher nearby in case of accidents.

Is it possible to achieve intricate cuts and shapes with a plasma cutter?

Yes, plasma cutters are capable of creating intricate and detailed cuts in metal. With practice and the right settings, you can achieve precision and create complex shapes for various applications, including art and fabrication.

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