Laser Engraving Anodized Aluminum, Stainless Steel and Brass
An asset tag, a stainless steel nameplate and a brass tool label can all carry a laser mark. They don’t all need the same process. Start with the metal and its finish, then decide whether you need light lettering, a dark surface mark or an engraving with depth.
What each laser can do
For Epilog engraving and marking systems, the useful distinction is:
| Material | CO₂ | Fibre |
|---|---|---|
| Anodized aluminum | Marks directly, without a compound | Marks directly, without a compound |
| Bare stainless steel | Uses a suitable metal marking compound | Marks the metal directly |
| Bare brass | Uses a suitable metal marking compound; test the result | Marks the metal directly |
Painted brass is a different job. A CO₂ laser can remove a suitable paint coating to reveal the brass underneath. That is different from engraving into bare brass or bonding a black mark to it. Identify the finish before choosing settings. Our metals page covers coated metals, anodized aluminum and marking compounds.
Anodized aluminum: light lettering without a compound
Epilog describes the CO₂ process as bleaching the colour in the anodized surface. Black anodized aluminum produces white lettering with strong contrast. Other colours can behave differently: red may leave a pink tint rather than turn completely white.
The aim is a clear surface mark. Epilog recommends high speed and low power for anodized aluminum; too much power can distort or over-burn the image. Test the actual colour and finish before running a batch of tags.
Fibre also marks anodized aluminum. Epilog’s fibre guides include focus adjustments to broaden the beam and improve brightness. Use the instructions for your source and machine rather than transferring a CO₂ setting.
CerMark on stainless steel and brass
A marking compound lets an engraving-class CO₂ laser put a dark mark on suitable bare metal. The laser bonds the compound to the surface. This process produces a surface mark rather than an engraving cut into the metal.
For stainless steel, Epilog describes a straightforward workflow: apply the marking material, let it dry, engrave, then wash away the unused material with water. Follow the compound manufacturer’s preparation instructions, including removing oils and applying an even coat.
Choose the compound for the metal. Vibrantz, the manufacturer of CerMark, lists stainless steel and brass among the substrates for its metal marking products. Its technical guide rates brass as more difficult to mark than stainless steel. Test the specific compound on your brass blank instead of assuming a successful stainless setting will transfer.
When comparing this route with fibre, include the coating, drying and cleaning steps in your workflow comparison.
What fibre changes
A fibre laser can mark bare stainless steel and brass directly, so the compound application and wash-off steps are unnecessary. The result depends on the process you choose:
- Etching or engraving removes metal to create the mark.
- Annealing on suitable metals, including stainless steel, changes the surface colour through heat without removing material.
- Polishing changes the surface finish and can produce a light or reflective mark.
Epilog publishes separate fibre settings for stainless steel annealing, etching and polishing, and for brass etching. Decide what the finished mark needs to look like before adjusting the laser. A dark stainless mark and a recessed part number are different targets.
Finding the right settings
Start with Epilog’s official material settings for your machine, source and wattage. The tables are starting points. Epilog advises testing the material and changing one variable at a time.
- Choose the correct process row. Anodized aluminum, stainless steel with marking solution, and bare-metal fibre marking have separate recommendations. Match the row to the job.
- Match the resolution to the artwork. For example, Epilog’s Fusion Pro CO₂ guide recommends 500 DPI for anodized aluminum text and notes that photos and clipart can work at 400 DPI. More resolution is not automatically the right starting point.
- Treat fibre frequency and focus as part of the setting. Epilog’s guides use speed, power, frequency and focus together. Annealing and etching use different focus conditions; copying only speed and power leaves out part of the process.
- Test on a spare piece of the actual stock. Start with a small section of lettering or a test grid. Adjust one variable, inspect the result and record the successful settings with the material, finish and machine.
For compounds, also follow the product maker’s settings guidance. Vibrantz notes that substrate thickness and heat conductivity affect the energy needed to make a good bond.
How durable is the mark?
Anodized aluminum: Epilog describes its laser marks as permanent and says the intended bleaching process preserves the anodized layer’s protective qualities. Follow the marking guidance rather than trying to drive the beam deeper into the metal.
CerMark: Vibrantz describes its LMM metal marks as permanent, with resistance to heat, mechanical wear, chemicals, UV and weathering. Its test procedure includes washing away the excess and scrubbing the sample with an abrasive kitchen pad to assess the bond. It also notes that durability depends on the underlying surface.
Fibre: Judge the process against the job. An annealed mark changes colour; an engraved mark removes metal. Specify the depth, contrast and service conditions you need, then test a sample under the cleaning and wear conditions the part will face.
Typical industrial uses
- Asset tags: identification numbers and barcodes on anodized aluminum or marked stainless steel.
- Nameplates and data plates: equipment identification, serial numbers and other variable information.
- Tools and components: part numbers, logos and traceability codes, using compound marking or direct fibre marking as the material requires.
Include the smallest text and any barcode in your sample evaluation. Check readability as well as appearance before approving a production run.
Talk through your application
Synergy Products is Canada’s exclusive Epilog dealer. Contact us with the metal, finish, quantity and type of mark you need, or book an appointment at our Delta, BC or Mississauga, ON showroom.
Compare the equipment on our Epilog laser systems page.
Questions About a Laser?
Call or send us your application. Demos are available at our Delta and Mississauga showrooms by appointment, or live online: send us your files and we'll run your parts on a real laser while you watch over video call.