Gas cutting (also known as oxy-fuel cutting) is—alongside plasma cutting—one of the most popular methods of cutting metals. It is used primarily for cutting low-carbon and low-alloy steels.

We have previously published an article comparing gas cutting to plasma cutting. Here, we revisit the key advantages and limitations of oxy-fuel cutting and explain the differences between propane-oxygen and acetylene-oxygen cutting.

Gas Cutting – How Does It Work?

Gas cutting involves heating the metal to its kindling temperature. An oxy-fuel torch ejects a high-pressure oxygen stream, having first mixed it with a fuel gas (acetylene or propane) in the correct ratio. When exposed to the flame, the metal ignites and oxidizes, turning into molten oxides that are blown away by the oxygen jet.

There are two main types of oxy-fuel cutting:

  • oxygen–propane cutting,

  • oxygen–acetylene cutting.

Both are widely used—each with its own strengths.

Advantages and Disadvantages of Gas Cutting

Key Advantages

The greatest benefit of oxy-fuel cutting compared to plasma cutting is its ability to cut very thick materials while maintaining high quality. Depending on the torch and nozzle selection, thicknesses from 3 mm up to approximately 200 mm can be cut effectively.

Gas cutting can be performed manually or mechanized.
Another advantage is the low cost of equipment and consumables.

Main Limitations

The main disadvantages include:

  • longer piercing time,

  • slower cutting speeds,

  • limitations regarding the type and thickness of material.

For thin materials (< 3 mm) or metals other than low-carbon steel, plasma cutting typically yields better results.

Propane or Acetylene? Choosing the Right Fuel Gas

Choosing the correct torch also determines which steels can be processed efficiently. Once you decide on oxy-fuel cutting, the next question becomes: propan or acetylen?
Your choice depends primarily on:

  • the material thickness,

  • the production method (manual vs. automated),

  • operating conditions (continuous work vs. frequent stops).

Oxy–Propane Cutting

Propane–oxygen cutting uses a propane–butane mixture along with oxygen. Propane is significantly less expensive than acetylene—both the gas and the associated consumables. Because propane burns at a lower temperature, its nozzles last longer.

Disadvantages of Propane

Propane heats the material three times slower than acetylene.
During frequent interruptions, operators may spend considerable time waiting for the material to reach kindling temperature, which can reduce economic efficiency.

For this reason, propane is recommended for:

  • long, continuous cuts,

  • automated cutting (CNC oxy-fuel tables),

  • thicker plates, where slow heating is less of an issue.

For thinner metal sheets, acetylene is typically the better choice.

Oxy–Acetylene Cutting

Acetylene is significantly more expensive, but offers far greater performance. It allows very rapid heating and reaches extremely high temperatures in a short time. This means:

  • lower gas consumption per cut,

  • higher efficiency during work with long idle periods,

  • excellent results on thin metal.

Acetylene can cut plate as thin as 3 mm, but also delivers high-quality results on thicker steel.

When is acetylene the better choice?

Acetylene is ideal for:

  • manual cutting,

  • workshop settings,

  • environments with frequent pauses between cuts,

  • cutting both thin and thick steel sheets.

Its main disadvantage is the higher operating cost, making it less suitable for high-volume mechanized production.

Is Oxy-Fuel Cutting Suitable for All Materials?

Not all metals can be cut using oxy-fuel technology. For cutting to occur, two conditions must be met:

  1. The ignition temperature of the metal must be lower than its melting point.

  2. The melting point of its oxides must be lower than the ignition temperature.

Metals that meet these conditions include:

  • iron,

  • titanium,

  • tungsten.

In practice, oxy-fuel cutting is used almost exclusively for low-carbon and low-alloy steels. As alloy content increases, cutting becomes more difficult, making high-alloy and high-carbon materials unsuitable for oxy-fuel processes.

Additionally, gas cutting is not suitable for very thin materials. Due to the large heat-affected zone, metals thinner than 3 mm cannot be separated effectively.

Despite these limitations, the usable thickness range for oxy-fuel cutting remains extremely broad. It is also significantly more cost-effective than plasma cutting for low-alloy and low-carbon steels—making it the best choice in many industrial applications.