What is Oxyfuel Cutting?

Oxyfuel cutting is a thermal cutting process that uses oxygen and fuel gas to cut through metals, mainly carbon steel. It works by preheating metal to ignition temperature and then using a stream of pure oxygen to rapidly oxidize the material, creating a precise cut.

For a complete overview of this process, this guide will explore:

• How oxyfuel cutting works
• Its applications across various industries
• Why it’s a valuable process for metal fabrication despite newer technologies

How Oxyfuel Cutting Works

Oxyfuel cutting leverages a chemical reaction between oxygen and heated metal. The process begins by heating the steel to approximately 1,800°F using a mixture of oxygen and fuel gas.

Once the metal reaches its ignition temperature, a stream of high-purity oxygen (99.5% or higher) is directed at the heated area. This oxygen causes the metal to rapidly oxidize or “burn.”

The resulting iron oxide has a lower melting point than the steel itself, allowing it to be blown away by the oxygen stream. This creates a kerf – the gap that forms the cut.

The preheat flames continue to travel alongside the oxygen jet, maintaining the metal’s temperature above ignition point as the cut progresses. This self-sustaining reaction continues as long as oxygen is supplied and the metal maintains the proper temperature.

For thicker materials, oxyfuel cutting requires higher oxygen pressures to effectively blow away the molten oxide and maintain a clean cut. This method is suitable for cutting steel plates up to 12 inches thick.

Fuel Gas Options for Oxyfuel Cutting

Oxyfuel cutting typically uses one of the following gases:

• Acetylene – produces the highest flame temperature (around 6,300°F) and is preferred for cutting thicker materials due to its fast preheating capability. Still, it requires careful handling due to its instability at high pressures.
• Propane – offers good stability and is more economical for many applications. While it produces a lower flame temperature than acetylene, it’s suitable for most standard cutting operations and is widely used in California fabrication shops.
• Natural gas (primarily methane) – provides a clean-burning alternative with lower costs, making it popular for high-volume operations. Its lower flame temperature means slightly longer preheat times but presents fewer safety concerns than acetylene.

Other gases like propylene and MAPP (methylacetylene-propadiene) can be considered as intermediate options, offering balanced performance between acetylene and propane in terms of flame temperature and stability.

Industrial Applications of Oxyfuel Cutting

Structural Steel Fabrication

Oxyfuel cutting excels in structural steel manufacturing for construction projects. Contractors in California and beyond rely on this process for creating beams, columns, and supports for buildings and bridges.

Fabrication shops use CNC-controlled oxyfuel cutting systems to process large steel plates with precision. The ability to cut thick sections cleanly makes it invaluable for heavy structural components.

The process allows for beveling edges in preparation for welding – a critical requirement for structural integrity in seismic-resistant construction throughout California’s earthquake zones.

Shipbuilding and Heavy Equipment Manufacturing

Shipyards use oxyfuel cutting extensively for processing thick steel plates used in hull construction. As the process can effectively cut steel plates up to 12 inches thick, its capabilities exceed many other cutting methods.

Heavy equipment manufacturers rely on oxyfuel cutting for producing components for excavators, bulldozers, and other construction machinery. The process handles the thick, high-strength steels required for these applications.

Many California equipment manufacturers choose oxyfuel cutting for its ability to process large workpieces that wouldn’t fit in laser or waterjet cutting machines.

Demolition and Scrap Processing

Oxyfuel cutting is the go-to method for on-site demolition work where portability is essential. Mobile cutting systems require only gas cylinders and a torch, which makes them ideal for field operations.

Scrap yards throughout California use oxyfuel torches to break down large metal structures and machinery for recycling. The process works effectively even on rusty or painted surfaces that might challenge other cutting methods.

The equipment’s simplicity and durability make it suitable for harsh environments where more sensitive cutting technologies would be impractical.

Advantages and Limitations of Oxyfuel Cutting

Oxyfuel cutting offers several advantages in industrial applications. The equipment is relatively inexpensive, portable, and doesn’t require electrical power – all of which makes it suitable for field work.

Unlike some cutting processes, oxyfuel cutting produces edges ready for welding without extensive preparation. This reduces additional processing steps in many fabrication workflows.

However, oxyfuel cutting does have limitations. Most notably, the process works effectively only on carbon steel and low-alloy steels. Standard oxyfuel methods aren’t suited for metals like:

• Stainless steel
• Aluminum
• Copper

This is because their oxides protect the base metal from further oxidation.

Oxyfuel cutting also creates a heat-affected zone that can change the metallurgical properties of the material near the cut. This may be a concern for applications requiring precise material characteristics.

Finally, oxyfuel cutting operates at slower speeds compared to plasma or laser cutting, particularly for thinner materials. This makes it less suitable for high-volume production of thin-gauge components.

Safety Considerations for Oxyfuel Operations

Working with oxyfuel equipment requires strict adherence to several safety protocols. This is because the combination of high-pressure gases and open flames presents significant hazards if mishandled.

Proper storage and handling of gas cylinders is essential. Cylinders must be:

• Secured upright
• Kept away from heat sources
• Equipped with the appropriate regulators and flashback arrestors

Personal protective equipment, including tinted eye protection, leather gloves, and flame-resistant clothing, is mandatory for all oxyfuel cutting operations. These precautions protect operators from sparks, slag, and intense light produced during cutting.

Ventilation requirements are particularly important in California facilities, where air quality regulations are strict. Adequate exhaust systems must be in place to remove fumes and particulates generated during cutting operations.

Finally, regular inspection and maintenance of equipment helps prevent gas leaks and ensures proper functioning of safety devices. This includes checking hoses, connections, and regulators before each use.

Modern Innovations in Oxyfuel Technology

While the basic principles of oxyfuel cutting haven’t changed significantly, modern systems incorporate advanced features for improved performance and safety.

Computer numerical control (CNC) has revolutionized oxyfuel cutting, enabling automated, precise cutting patterns. Modern machines can store hundreds of cutting programs and optimize material usage through nesting software.

High-definition torch tips are also used to improve cut quality by focusing the oxygen stream more precisely. These innovations reduce kerf width and improve edge squareness, which is especially important for parts that will be welded without additional preparation.

Finally, integrated sensing systems can automatically adjust preheat time and oxygen pressure based on material thickness. This ensures optimal cutting parameters without operator intervention.

Leverage Oxyfuel Cutting in Your Operations

Oxyfuel cutting is a cornerstone technology in metal fabrication despite the emergence of newer cutting methods. Thanks to its ability to process thick steel economically, equipment portability, and simplicity, this process enjoys continued relevance in construction, shipbuilding, and heavy equipment manufacturing.

While plasma and laser cutting may offer advantages for thinner materials and non-ferrous metals, oxyfuel cutting maintains its position as the preferred method for thick carbon steel plates. Understanding its capabilities and limitations helps fabricators choose the right process for their specific applications.

Tyler O'Brien

Tyler is a results-driven marketing professional specializing in the industrial gases and equipment industry, bringing his 10 years of technical expertise and digital marketing acumen to the complex industrial gas B2B environment.