Carbon Steel Fiber Laser Cutting Parameter Chart: 1.5kW to 20kW Speed & Gas Guide
Practical carbon steel fiber laser cutting parameter chart covering cutting speeds, assist gas (O2/N2/Air), nozzle selection, and pressure settings from 1.5kW to 20kW.
Optimizing carbon steel fiber laser cutting parameters directly governs edge quality, cutting speed, dross accumulation, and operating cost. While machine vendors specify maximum theoretical cutting thickness, production success requires repeatable process parameters balanced between laser power, assist gas selection (Oxygen vs Nitrogen vs Compressed Air), nozzle diameter, and focal position.
1. Carbon steel cutting parameters reference chart (1.5kW - 20kW)
The table below provides production-tested reference parameters for cutting standard mild/carbon steel plates (Q235, SS400, A36). Use these baseline settings as initial setups before fine-tuning for surface oxide conditions.
| Thickness (mm) | Laser Power | Cutting Speed (m/min) | Assist Gas | Gas Pressure (bar) | Nozzle Type & Size | Focus Offset (mm) |
|---|---|---|---|---|---|---|
| 1.0 mm | 1500W | 18.0 - 24.0 | Air / N2 | 12.0 - 15.0 | Double 1.5mm | -0.5 to 0 |
| 3.0 mm | 1500W | 4.5 - 6.0 | O2 (Oxygen) | 0.8 - 1.2 | Double 1.4mm | 0 to +1.0 |
| 6.0 mm | 3000W | 2.2 - 2.8 | O2 (Oxygen) | 0.7 - 0.9 | Double 1.6mm | +1.5 to +2.5 |
| 10.0 mm | 6000W | 2.4 - 3.2 | O2 (Oxygen) | 0.5 - 0.7 | Double 2.0mm | +3.0 to +4.5 |
| 16.0 mm | 6000W | 1.2 - 1.6 | O2 (Oxygen) | 0.5 - 0.6 | Double 2.5mm | +4.0 to +5.5 |
| 20.0 mm | 12000W | 1.6 - 2.2 | O2 (Oxygen) | 0.4 - 0.5 | Double 3.0mm | +5.0 to +7.0 |
| 30.0 mm | 20000W | 1.1 - 1.5 | O2 (Oxygen) | 0.35 - 0.45 | Double 3.5mm | +7.0 to +9.5 |
2. Assist gas selection: Oxygen vs Nitrogen vs Compressed Air
Assist gas selection dictates both edge finish and hourly cutting economy in carbon steel fabrication:
- Oxygen (O₂ Cutting): The standard method for medium and thick carbon steel (3mm - 50mm). Exothermic reaction generates additional heat, allowing lower laser power to cut thicker plates at low pressure (0.4-1.0 bar). Limitation: Leaves an oxide layer on the cut edge that requires removal before powder coating or painting.
- Nitrogen (N₂ High-Pressure Cutting): Used for carbon steel under 6mm when an oxide-free, weldable/paintable silver edge is required immediately without deburring. Limitation: Requires high pressure (14-20 bar) and high laser power (6kW+), increasing per-meter gas costs.
- High-Pressure Compressed Air (16-18 bar): The most cost-effective alternative for thin carbon steel (under 3mm). When paired with a four-stage filtration air compressor and refrigerated dryer, per-meter cutting cost drops by 60% compared to bottled nitrogen.
3. Common cutting defects and troubleshooting
- Bottom Dross / Burrs: Often caused by excessive cutting speed, low gas pressure, or positive focus placed too high. Decrease speed by 10% or reduce nozzle-to-plate standoff distance to 0.8mm.
- Corner Overburning (Melting Corners): Concentrated heat causes thermal runaway in sharp corners. Enable lead-in loops, corner power decay (cooling curves), or automatic pause cycles in the BOCHU CypCut controller.
- Rough Striations: Caused by unstable oxygen pressure or dirty protective focus lenses. Ensure O2 purity exceeds 99.5% and clean or replace cover glass.
Matched CNC equipment from PFT
Review the PFT-3015 3000W-12000W single platform model, examine the enclosed production PFT-6020H exchange table system, or explore the wider fiber laser cutting machines collection. Request a customized cutting parameters sheet and quotation for your specific plate grades.
