Does a Plasma Cutter Cut Aluminum? Yes, and Here Is How
Does a plasma cutter cut aluminum? Yes, and it is one of the main reasons people pick plasma over an oxy-fuel torch, which cannot cut aluminum at all. Because a plasma cutter works on any electrically conductive metal, aluminum is fair game, and plasma is the standard tool for cutting aluminum sheet and plate quickly and cleanly. The one thing to understand is that aluminum behaves a little differently under the arc than steel, so a clean edge comes down to a few setup choices. Here is the straight answer and how to do it well.
The short answer, and why
Yes, a plasma cutter cuts aluminum. An oxy-fuel torch cannot, because it cuts by burning (oxidizing) the metal, and aluminum does not oxidize the way carbon steel does. A plasma cutter does not rely on burning; it melts the metal with an electric arc and blows it away with fast-moving plasma. Since aluminum conducts electricity, plasma cuts it exactly as it cuts steel or stainless. That is why plasma is the standard aluminum-cutting tool.
What is different about aluminum
Aluminum conducts heat away quickly and melts at a lower temperature than steel, so it cuts fast but has a couple of quirks:
- More underside dross than steel, especially at the wrong speed or amperage.
- A slightly rougher edge on thicker sections.
- Heat spread on thin sheet if you cut too slowly.
The setup below manages these.
The setup for clean aluminum cuts
Amperage to thickness: use enough amperage to cut cleanly through (aluminum pulls heat away, so do not starve it), but drop to a lower-amp tip on thin sheet to keep the kerf narrow. Thin aluminum cuts on a small machine; 1/2-inch aluminum wants a 50-amp-class machine or higher.
Air supply: clean, dry, oil-free air at the right pressure and flow. Correct pressure gives the plasma velocity to blow molten aluminum clear, reducing dross. Moisture especially hurts aluminum, so use a filter/dryer.
Cut speed: dial it so sparks blow cleanly out the bottom. Aluminum generally likes a slightly faster travel than steel; too slow overheats it and leaves heavy dross, too fast leaves an incomplete cut.
Consumables and standoff: keep the electrode, nozzle and shield fresh, and use the drag shield or correct standoff for a square edge.
Reducing dross on aluminum
Dross, the clinging molten metal on the bottom edge, is the most common aluminum complaint. To minimize it: get the cut speed right (the single biggest factor), use adequate amperage and correct air pressure, and keep consumables fresh. Even with perfect setup, aluminum is simply more dross-prone than steel, so a little cleanup is normal.
How thick can it cut?
Up to the machine’s cut capacity. A 50-amp machine handles around 1/2 inch of aluminum, and larger 65-amp-plus systems cut thicker. As with any metal, match the machine’s rated cut capacity to your aluminum thickness rather than the severance number.
The verdict
Yes, a plasma cutter cuts aluminum, and doing so is one of its biggest advantages over an oxy-fuel torch, which cannot touch aluminum. Whether the edge comes out clean is decided by setup, not by the metal being hard to cut.
Three things to get right. Match amperage to thickness, enough to cut cleanly since aluminum pulls heat away, but a lower-amp tip on thin sheet to keep the kerf narrow. Feed clean, dry air at correct pressure, because moisture hurts aluminum cut quality and proper pressure blows the molten metal clear to reduce dross. And dial cut speed with fresh consumables, since speed is the biggest factor in dross and worn parts widen the kerf.
Set those, expect a little more underside dross than on steel, and a plasma cutter turns aluminum from a metal the torch cannot cut into fast, clean work.
Frequently asked questions
Does a plasma cutter cut aluminum? Yes. Plasma cuts any electrically conductive metal by melting it with an arc and blowing it away, and aluminum conducts electricity, so it cuts just like steel or stainless. Plasma is the standard tool for aluminum, which an oxy-fuel torch cannot cut.
Why can plasma cut aluminum when a torch cannot? An oxy-fuel torch cuts by burning (oxidizing) the metal, which aluminum does not do the way carbon steel does. A plasma cutter melts the metal with an electric arc instead of burning it, so it cuts conductive metals like aluminum that a torch cannot.
Does aluminum need a special plasma setup? The fundamentals match steel, but aluminum generally likes a slightly faster travel speed and is less forgiving of moist air and worn consumables. Match amperage to thickness, keep the air clean and dry, and use a lower-amp tip on thin sheet.
Why does aluminum leave more dross? Aluminum conducts heat away quickly and melts at a lower temperature, making it naturally more prone to clinging underside dross than steel, especially at wrong speed or amperage. Correct speed, air pressure and fresh consumables minimize it.
How thick of aluminum can a plasma cutter cut? Up to the machine’s cut capacity. A 50-amp machine handles around 1/2 inch, and larger 65-amp-plus systems cut thicker. Match the machine’s rated cut capacity to your aluminum thickness rather than the severance number.
What amperage do I need to cut aluminum? Enough to cut cleanly through the thickness, since aluminum pulls heat away, but a lower-amp tip on thin sheet to keep the kerf narrow. Thin sheet cuts on a small machine; 1/2-inch aluminum wants a 50-amp-class machine or higher.
How do I get less dross cutting aluminum? Get the cut speed right (the biggest factor), use adequate amperage and correct air pressure, and keep consumables fresh. Even with perfect setup, aluminum is more dross-prone than steel, so expect a little cleanup.
Do I need special consumables for aluminum? Not usually; the same cutting consumables work, though keeping them fresh matters more since worn parts widen the kerf and worsen aluminum’s tendency to dross. A lower-amp tip and correct pressure give the cleanest thin-aluminum cuts.
