How to Laser Engave Blank Coin

Here’s a step-by-step guide for laser engraving a blank 3mm metal coin.

⚠️ Critical First Step: Before anything else, confirm your laser type can engrave bare metal.

  1. Fiber Laser (MOPA/20W+) : Best choice. Works perfectly out of the box.
  2. Diode Laser (Blue Light, 5W–20W) : Cannot engrave raw, shiny metal. Use spray (Brilliance/ Dry Moly Lube) or buy diode-coated blanks.
  3. CO₂ Laser : Cannot mark metal directly (requires special spray).

1. Prepare Your Blank

  1. Clean the surface with isopropyl alcohol (removes oil & fingerprints).
  2. For stainless steel/brass with a diode laser: Apply a thin, even coat of laser marking spray.
  3. Let it dry completely (usually 5–10 min) before engraving.

2. Create Your Design

  • Use LightBurn (most common) or LaserGRBL.

  • Recommended settings (for Fiber laser, 20W on brass/stainless):

  1. Speed: 200–400 mm/s
  2. Power: 60–80%
  3. Frequency: 30–50 kHz
  4. Passes: 1 (usually)

  • For Diode + Marking Spray (10W Diode):

  1. Speed: 1000–2000 mm/min
  2. Power: 70–100%
  3. Passes: 2–3

  • Invert image to black = engraved, white = untouched.

3. Focus & Test

  • Set focus precisely (small metal coins are unforgiving).
  • Crucial: Run a small test grid on a spare coin or the edge/back of your blank.
  • Test small variations in power/speed to find the sweet spot.

4. Laser & Post-Process

  • Press “Start” and monitor the job (especially with spray – burns quickly).
  • If you used marking spray: Wash the coin gently with soap and warm water to remove residue.
  • Clean again with alcohol and dry.

5. Finish (Optional)

  • Brass/copper: will darken over time. Protect with clear lacquer spray.
  • Stainless steel: stays silver/black (high contrast).
  • Add color fill: wipe acrylic paint into engraved recesses, then wipe off excess.

✅ Checklist Before You Start



Question Answer
Is my blank clean & spray-coated (if diode laser)? ✅ / ❌
Have I focused correctly? ✅ / ❌
Did I run a test engrave on a scrap coin? ✅ / ❌
Are my material settings saved in LightBurn? ✅ / ❌

🛠️ Troubleshooting (Quick Fixes)



Problem Likely Cause Fix
No mark on metal Wrong laser type / no spray Use spray or switch to fiber laser
Mark washes off Just spray residue, not real engraving Increase power, reduce speed
Burned/melted edge Too much power / too slow Raise speed, lower power
Uneven engraving Uneven focus or dirty lens Re-focus, clean lens gently

 

If you tell me your specific laser model (e.g., Xtool D1 Pro 10W, Raycus 20W Fiber,Commarker b4, b6,titan), I can give you exact settings to start with.

Back to blog

Leave a comment