Choosing the wrong cutting nozzle is one of the most common — and costly — mistakes in fiber laser operations. The wrong bore diameter causes poor cut quality; the wrong thread wastes time and risks head damage. This guide covers the fundamentals.
Single Layer vs Double Layer: When Does It Matter?
Single-layer nozzles (like our D28 Single Layer, M11) are the standard choice for most cutting applications — mild steel, stainless steel, and aluminium up to around 10mm. They provide a clean, focused gas flow and are available in bore diameters from 1.0mm to 4.0mm.
Double-layer nozzles add an inner precision tip that creates a more concentrated gas stream. This matters on thick plate (12mm+) where you need the gas to punch through the melt more aggressively, and on materials where dross is a persistent problem. The tradeoff: double-layer nozzles are slightly more expensive per unit and more sensitive to contamination.
Bore Diameter Selection
| Material Thickness | Recommended Bore | Assist Gas |
|---|---|---|
| 1 – 3mm | 1.0 – 1.5mm | N₂ or O₂ |
| 3 – 8mm | 1.5 – 2.0mm | N₂ or O₂ |
| 8 – 16mm | 2.0 – 2.5mm | O₂ (steel) / N₂ (SS) |
| 16mm+ | 2.5 – 4.0mm | O₂ or high-pressure N₂ |
Thread Compatibility
Most major Chinese cutting heads (Raytools BM110/BT240S/AT300, WSX NC12/NC30, BOCI, Han’s, Ospri, Qilin) use the M11×1 thread and fit the D28 nozzle family. European-origin heads and Chinese premium heads (Precitec ProCutter, Bodor B3015) use the M14×1 thread with the D32 family.
Always verify your cutting head’s thread specification before ordering. A mismatched thread can permanently damage the head’s nozzle seat.
Surface Finish: Natural vs Chrome-Plated
Natural copper nozzles conduct heat well and are the default choice for most operations. Chrome-plated nozzles offer slightly better spatter resistance and are preferred in high-duty-cycle environments where spatter build-up is a cleaning problem.
Replacement Interval
A well-maintained copper nozzle should last 40–80 cutting hours depending on material and power settings. Signs it’s time to replace: visible bore deformation, inconsistent edge quality, increased gas consumption, or capacitive height sensing instability.
All NEXORA nozzles are individually pressure-tested before dispatch. MOQ 3 pcs, with volume tiers from 50 pcs. Contact us with your head model for a compatibility check and quote within 6 hours.
