Fiber Laser Cutting Parameters Chart – Speed, Power, Gas Settings

Before You Cut — Pre-Flight Checklist

Run through these checks every shift, or anytime cut quality degrades unexpectedly. Most "parameter problems" are actually maintenance problems.

Protective Lens / Window

Inspect the protective lens before every shift. It must be free of water, oil, spatter, and burn marks. A contaminated lens can cut your effective power by 30% or more — and if it gets bad enough, it can damage the focus lens and collimator above it. Clean with approved lens solution and lint-free wipes only.

Nozzle Centering / Beam Alignment

The laser beam must be centered in the nozzle. An off-center beam causes good cuts in one direction and bad cuts in the other. Use a 1.0mm nozzle to check — tape over the tip, pulse the beam at low power, and confirm the burn mark is dead center. Re-center if the dot is off by more than 0.1mm.

Nozzle Condition

Check the nozzle orifice for roundness and damage. A dented, oval, or spatter-clogged nozzle distorts gas flow and ruins cut quality. Replace nozzles regularly — they're cheap consumables. Ensure the correct nozzle type is installed (single-layer for N₂, double-layer for O₂).

Focus Calibration

If using an auto-focus cutting head, verify calibration with the manufacturer's app or test routine. Focus drift is a common cause of gradual quality loss that operators blame on parameters. On manual-focus heads, re-measure with gauge pins when switching nozzle sizes.

Troubleshooting — What Your Cut Is Telling You

Dross / Slag on Bottom Edge

Hard, welded-on dross: Lower the focus position, increase gas pressure, and try a larger nozzle diameter. Check nozzle centering.
Soft, granular dross: Increase cutting speed slightly or reduce power. The beam is dwelling too long.
Dross only at end of cuts: Check gas supply — you may be running out of flow at the end of long cuts.

Rough or Striated Cut Edge

Vertical striations: Reduce cutting speed by 10–15%. The beam is moving too fast for clean melt ejection.
Diagonal drag lines: Focus position may be off. Adjust in 0.5mm increments. Check lens cleanliness.
Rough only on one side: Nozzle is not centered. Re-center before adjusting anything else.

Burning / Overmelting on Corners

On carbon steel with O₂, reduce power 10–20% at corners or enable corner deceleration in your controller. Excessive oxygen at low speed causes over-burning. On stainless/aluminum, reduce speed into corners and add a small radius (0.3–0.5mm minimum) to sharp inside corners.

Incomplete Penetration / Not Cutting Through

First check: protective lens cleanliness — a dirty lens can reduce effective power by 30%. Then reduce speed by 10%. If still not penetrating, check focus calibration with auto-focus app. For thick material near maximum capacity, ensure gas pressure is at full recommended level and nozzle isn't worn.

Yellow/Blue Edge Discoloration (Stainless)

Nitrogen purity is likely too low — you need 99.95%+ for bright edges. Also check for leaks in gas delivery. If using air, slight discoloration is expected and normal. Increasing N₂ pressure by 1–2 bar can help. On PVC-coated material, some heat tint beneath film is acceptable if the exposed edge is clean.

Excessive Spatter on Top Surface

Usually a pierce issue. Increase pierce delay time, or use ramped piercing for thick material. Check that cutting height (nozzle standoff) is 0.8–1.2mm. On aluminum, ensure your N₂ pressure is high enough — spatter indicates molten material isn't being blown downward cleanly.