Stainless steel is one of the materials laser cutting machines are most adept at and most commonly process. The answer to the question, "Which laser cutting machine is best for cutting stainless steel?" is clear:
The preferred, and almost exclusive, choice is: fiber laser cutting.
Below, I'll explain why in detail and provide a selection and usage guide.
I. Why is the fiber laser cutting machine the best choice for cutting stainless steel?
1. Extremely High Absorption: Stainless steel has a very high absorption rate for fiber lasers (wavelength approximately 1.06μm), meaning that most of the laser energy is effectively utilized by the material rather than being reflected, resulting in extremely high cutting efficiency.
2. Excellent Cutting Quality:
Smooth Cross-Section: The cut edge is virtually burr-free and extremely bright, achieving a "mirror-like" finish.
Extremely High Precision: The narrow kerf and minimal heat-affected zone do not alter the material's inherent properties, making it particularly suitable for precision machining.
3. High Cutting Speed: Especially when cutting thin and medium-sized plates, the cutting speed is much faster than traditional processes like plasma cutting and water jet cutting, significantly improving production efficiency.
4. Low Operating Costs: Fiber lasers have high electro-optical conversion efficiency (reaching over 30%), consume far less power than CO2 lasers, and require virtually no consumables.
While traditional CO2 lasers can cut stainless steel, they are no match for fiber lasers in terms of efficiency, energy consumption, and cost.
II. How to Choose the Right Fiber Laser Cutting Machine?
The choice of fiber laser machine depends primarily on your material thickness, production requirements, and desired cutting quality.
| Stainless Steel Thickness | Recommended Laser Power | Description and Application Scenarios |
| Thin Plates (≤3mm) | 500W - 1000W | Extremely fast cutting speeds and excellent quality. Suitable for kitchenware, appliance panels, decorative items, advertising signs, etc |
| Medium Plates (3mm - 8mm) | 1000W - 3000W | This is the most commonly used power range, offering the best balance between speed and quality. Suitable for cabinets, mechanical equipment, kitchenware, stainless steel components, etc. |
| Thick Plates (8mm - 20mm) | 3000W - 6000W | Requires higher power to ensure cutting quality and speed. Suitable for industrial equipment, large structural parts, thick-walled pipes, etc. |
| Extremely Thick Plates (>20mm) | 6000W and above | Higher power increases the ability to cut thicker plates and improves cross-sectional quality. However, this also significantly increases costs. |
Other Important Selection Considerations:
Equipment Specifications: Select the appropriate machine work surface based on the plate sizes you typically process (e.g., 3015, 4020, 6020, etc.).
Automation Requirements: For mass production, consider an automatic loading and unloading system to improve efficiency.
Brand and After-Sales Service: Choose a brand with proven technology and comprehensive after-sales service to ensure stable equipment operation and timely technical support.
III. Key Points in Stainless Steel Cutting
Even with superior equipment, correct process parameters are crucial. Focus on the following:
1. Assist Gas (Critical!)
Preferred: Nitrogen (N₂)
Effect: High-pressure cutting using high-purity nitrogen (≥99.99%) is considered "melt cutting." The nitrogen's protective shield prevents oxidation from occurring at the cut surface.
Resulting Surface: A silvery-white, shiny cut surface is aesthetically pleasing, requiring no secondary treatment and suitable for welding or product finishes.
Cost: Gas costs are relatively high, but it is a necessary investment for high-quality results.
Alternative: Oxygen (O₂)
Effect: Using oxygen is considered "oxidation cutting." Oxygen reacts exothermically with the molten stainless steel, improving cutting performance.
Resulting Surface: A black oxide layer forms on the cut surface, resulting in a rough, low-quality surface.
Application: Only suitable for rough machining or blanking where the appearance of the cut surface is not critical.
2. Focus Position: Adjust the laser focus position according to the plate thickness to achieve the narrowest kerf and optimal cross-section quality.
3. Cutting Speed and Power: Power and speed must be matched. For a given power, too fast a speed will result in a partial cut, while too slow a speed will cause excessive melting and excessive dross.
Summary
For stainless steel cutting, choose a fiber laser cutting machine.
Select the appropriate power based on the thickness you're primarily processing: 1500W-3000W is generally recommended for the widest range of applications.
To achieve a bright cross-section, high-purity nitrogen must be used as the assist gas.
Final advice: Before purchasing equipment, it's best to provide your specific sample (material and thickness) to the equipment supplier for a field test cut. This is the most direct and reliable way to verify the equipment's performance and cutting results.