Fiber laser cutting machines require auxiliary gases to achieve clean, efficient cuts, whether for sheet metal or pipes. The most commonly used gases are oxygen, nitrogen, and compressed air, each serving different purposes depending on material type, thickness, and desired cutting quality.
Below, we explore the differences between these gases and their optimal applications in laser cutting.
1. Compressed Air – Cost-Effective Cutting for Non-Critical Surfaces
Best for: Aluminum, galvanized steel, and non-ferrous metals
Key Benefits:
- Reduces oxide formation on the cut edge.
- Lower operational cost compared to nitrogen and oxygen.
- Suitable for thicker sheets where a perfect finish is not required.
Limitations:
- Not ideal for high-precision cutting due to potential oxidation.
- Cutting speed and edge quality are inferior to nitrogen for stainless steel.
2. Nitrogen – High-Quality, Oxidation-Free Cutting
Best for: Stainless steel, aluminum, and other metals requiring a clean finish
Key Benefits:
- As an inert gas, nitrogen prevents oxidation and burning during cutting.
- Produces bright, burr-free edges, ideal for cosmetic or weld-ready surfaces.
- Essential for thin to medium-thick sheets where precision matters.
Limitations:
- Higher cost compared to compressed air.
- Not suitable for thick carbon steel cutting (oxygen is better for such applications).
3. Oxygen – High-Speed Cutting for Thick Carbon Steel
Best for: Thick carbon steel plates and structural parts
Key Benefits:
- Acts as a combustion aid, increasing cutting speed and penetration.
- Enables thicker material cutting (e.g., heavy steel plates).
- More cost-effective than nitrogen for carbon steel applications.
Limitations:
- Causes oxidation, leading to a darkened cut edge (not suitable for stainless steel).
- Requires careful pressure control to avoid excessive slag formation.
Optimizing Gas Pressure for Best Cutting Performance
While increasing gas pressure can boost cutting speed, excessive pressure may lead to:
- Reduced cut quality (rough edges, increased dross).
- Diminished speed gains after reaching a peak point.
- Best Practice:
- Test different pressures during machine setup to find the optimal balance.
- Adjust gas type and flow rate based on material thickness and desired finish.
Conclusion
Choosing the right auxiliary gas is crucial for efficiency, cost savings, and cut quality in fiber laser cutting:
- Compressed air → Budget-friendly for aluminum and galvanized steel.
- Nitrogen → Best for oxidation-free, high-precision cuts.
- Oxygen → Ideal for fast, thick carbon steel cutting.
Proper gas selection and pressure control ensure maximum cutting performance while minimizing operational costs.
If you would like to learn more, please contact us at rayther@raytherlasercutter.com
-- Rayther Laser Allen Wang