Guide Draft, needs technical review
CNC Plasma Cutting vs Gas Cutting: How to Choose
By PT Abadi Baru Teknikatama · · 2 min read · Last updated: 8 October 2026
Summary
Gas (oxy-fuel) cutting and plasma cutting both cut metal plate, but they work in different ways. Oxy-fuel is generally used for carbon steel, including thick plate. Plasma cuts all electrically conductive metals and is generally faster on thin to medium plate. This guide helps you choose one process, or a combination of both, on a CNC cutting machine.
On a CNC cutting machine, the cutting path is controlled by a program, so the same shape can be repeated consistently. What needs to be decided is the cutting process: gas (oxy-fuel), plasma, or both.
How does gas (oxy-fuel) cutting work?
The steel is heated with a gas flame to its ignition temperature, then a jet of pure oxygen oxidizes the metal and blows the oxidation products out of the kerf. Because it relies on the oxidation reaction of iron, this process is generally used for carbon steel and low-alloy steel.
Its advantage is that oxy-fuel can cut very thick plate with a relatively low equipment investment. Its drawback is that preheating time is needed and the cutting speed is low on thin plate.
How does plasma cutting work?
An electric arc is passed through a gas that is constricted in the nozzle until it becomes plasma at a very high temperature. The plasma melts the metal and its gas flow blows the molten metal out.
Because it cuts by melting, plasma can be used on all electrically conductive metals: carbon steel, stainless steel, aluminium, copper. Cutting speed is generally high on thin to medium plate. Plasma requires electricity, an air or gas supply, and periodic replacement of the torch consumables.
Comparison table
| Gas (oxy-fuel) | Plasma | |
|---|---|---|
| Material | Carbon steel, low-alloy steel | All electrically conductive metals |
| Thin plate | Slow | Fast |
| Very thick plate | Suitable | Depends on the capacity of the plasma power source |
| Preheating | Required | Not required |
| Utility requirements | Fuel gas and oxygen | Electricity, compressed air or gas |
| Consumable parts | Cutting nozzle | Torch electrode and nozzle |
Questions that help you choose
- What material do you cut most often? If stainless steel or aluminium is involved, plasma is required.
- What thickness range do you cut routinely, and what is the thickest?
- What is the largest plate size? This determines the effective width and length of the machine.
- How high is the cutting volume per day? High volumes benefit from multi-torch setups and automatic nesting.
- What utilities are already available: electrical power, compressor, gas?
- Machine type: gantry for repetitive plate production, or portable for workshops with limited space and budget?
For workshops that cut thick carbon steel as well as thin plate or stainless steel, a combination of both processes on one machine is often the middle ground.
Include the answers to the questions above when requesting a quotation, so that the machine configuration and plasma power source offered suit your work.
Frequently Asked Questions
Why is oxy-fuel not used for stainless steel and aluminium?
Oxy-fuel cuts by oxidizing the metal. On stainless steel and aluminium, an oxide layer forms that inhibits this reaction, so the process is generally used only for carbon steel and low-alloy steel.
Can one CNC machine use both plasma and gas?
Yes. Many gantry-type CNC cutting machines can be fitted with a plasma torch and a gas torch on the same machine, so the operator selects the process according to the material and thickness.
What determines the cutting thickness of a plasma machine?
Mainly the current capacity of the plasma power source and the type of torch. The higher the current, the thicker the material that can be cut. The exact capacity needs to be checked in the technical data of the plasma power source.
Discuss your requirements with the Abadi Baru team
Tell us about the job, the material and the capacity required. The sales and technical teams help with a recommendation before a quotation is prepared.