| Laser Power (kW) | Mild Steel (O₂) | Mild Steel (Air) | Stainless Steel (N₂) | Stainless Steel (Air) | Aluminum (N₂) | Aluminum (Air) | Copper (N₂) | Copper (Air) | Brass (N₂) | Brass (Air) |
| 2kW | 12mm | 3mm | 6mm | 3mm | 4mm | 3mm | 3mm | 2mm | 3mm | 2mm |
| 4kW | 15mm | 4mm | 10mm | 6mm | 8mm | 6mm | 5mm | 4mm | 5mm | 4mm |
| 6kW | 20mm | 6mm | 15mm | 10mm | 10mm | 8mm | 8mm | 6mm | 8mm | 6mm |
| 8kW | 25mm | 8mm | 20mm | 15mm | 12mm | 10mm | 10mm | 8mm | 10mm | 8mm |
| 10kW | 30mm | 10mm | 25mm | 18mm | 15mm | 12mm | 12mm | 10mm | 12mm | 10mm |
| 12kW | 35mm | 12mm | 30mm | 20mm | 18mm | 15mm | 15mm | 12mm | 15mm | 12mm |
| 15kW | 40mm | 15mm | 35mm | 25mm | 20mm | 18mm | 18mm | 15mm | 18mm | 15mm |
| 20kW | 50mm | 20mm | 40mm | 30mm | 25mm | 20mm | 20mm | 18mm | 20mm | 18mm |
| 25kW | 60mm | 25mm | 50mm | 35mm | 30mm | 25mm | 25mm | 20mm | 25mm | 20mm |
| 30kW | 70mm | 30mm | 60mm | 40mm | 40mm | 30mm | 30mm | 25mm | 30mm | 25mm |
Notes on Copper and Brass:
- Assist Gas: High-purity Nitrogen (N2) or compressed air is often used to cut copper and brass.
- Reflectivity: Copper and brass are highly reflective, which can limit cutting performance on lower-power lasers unless reflectivity protection is in place.
- Thermal Conductivity: These metals have high thermal conductivity, requiring more power to cut thicker sections.
Notes:
- Assist Gas: Oxygen (O2) is typically used for mild steel to boost energy through exothermic reactions, while Nitrogen (N2) is used for stainless steel and aluminum for clean, oxide-free edges.
- Material Type and Quality: The maximum cutting thickness also depends on material grade and surface condition.
- Laser Parameters: These include focus position, nozzle design, and cutting speed.
Key Points:
- Compressed Air:
Often used as a lower-cost alternative to nitrogen.
Can cut mild steel, stainless steel, aluminum, copper, and brass effectively, but results in slightly more burr and oxidation compared to nitrogen or oxygen on thicker material.
Rule of thumb, 2 kw will cut 2mm using compressed air free of burr, 4kw: 4mm, 6kw: 6mm etc
- Performance:
Compressed air is a mix of nitrogen (78%) and oxygen (21%) with traces of other gases, which means it provides moderate cutting quality between nitrogen and oxygen.