Best fiber laser settings for deep engraving mild steel

Fiber Galvo50 W–100 WIndustrial

Deep engraving removes material pass after pass, so total depth is mostly a function of pass count and power. These are starting points for a 50–100 W galvo; expect to run many passes for visible depth and to refocus between depth steps on tall features.

Starting point — not a recipe. Run a material test on your own machine. Every laser, lens, gas supply, and material batch is different. These numbers exist to shrink your test, not replace it.

Recommended starting-point parameters

Power80–100%
Speed300–800 mm/s
Frequency20–40 kHz (lower = more peak energy per pulse)
Passes20–80+ depending on target depth
Line interval / hatch0.02–0.04 mm, cross-hatch (0°/90°)
RefocusStep focus down ~0.1 mm per several passes for deep cavities

Dialing it in

  • Cross-hatching (alternating 0°/90° fill) gives a flatter, cleaner cavity floor.
  • Air assist or a fume extractor keeps debris from re-depositing and slowing subsequent passes.
  • Depth per pass is small and varies with focus — measure after a known pass count to calibrate.

The material-test workflow

The fastest way to a reliable cut is not a perfect chart — it's a tight test loop that you only run once per machine/material combination, then never repeat:

  1. 1Start from this baseline. Load the starting-point numbers above as the center of your test.
  2. 2Run a small array. Cut a grid that sweeps speed (and power, if cutting) ±20% around the baseline — typically 9–16 small squares.
  3. 3Judge the edge. Look for dross, burn-back, kerf width, and squareness. Pick the square that meets your part's requirement, not the prettiest one.
  4. 4Log it once. Save the winning parameters against this exact machine + material so the next job starts from your proven number — not a generic chart.

Stop re-running the same test square

CutLog gives you a starting point calibrated to your wattage and lens, then remembers every cut you log — so your machine builds its own proven library. Free to start.

Frequently asked questions

How many passes to deep-engrave steel with a fiber laser?

Depth builds up gradually. A 50–100 W galvo typically needs anywhere from 20 to 80+ passes at full power and 20–40 kHz, refocusing as the cavity deepens. Calibrate by measuring depth after a known number of passes on a test coupon.

Related settings

Last reviewed 2026-06-28. Values are conservative starting points generalized across brands and published cutting charts; always verify on your own machine.