What laser engraving is
Laser engraving uses a focused beam to remove material from the surface, leaving a mark that is permanent because it is the metal itself rather than an applied layer. Depth is the main process variable — typically 0.01–0.2 mm depending on the substrate and the contrast required. Because the mark is subtractive it works equally well on bare metal, on anodized aluminium, on plated steel and on a powder-coated surface.
Legibility, not depth, is the constraint. A deep mark holds its character better, but it costs more, puts more heat into the part, and on a thin or already-finished surface can be a problem. The drawing therefore states the character height and the depth, and legibility is judged against the smallest character the process can hold cleanly at the contrast required.
- Subtractive: removes 0.01–0.2 mm to leave the mark
- Works on all base metals, and over anodizing, plating and powder coat
- Permanent — the mark is the material, not an applied layer
- Specify text, character height, font, depth and datum
- State whether marking happens before or after the other finishing steps
What goes on the drawing
Four things, and they are the difference between a mark and a rework. The text itself, exactly as it must read, including characters and punctuation. The character height, because legibility is governed by the smallest character. The depth, where the surface is finished and the mark has to stay clear of the finish. And the datum, so the mark lands in the right place on the part rather than approximately where the drawing implied.
The sequence question matters as much as the geometry. Marking an anodized part removes the anodic layer and exposes bright metal underneath, so light parts read dark and dark parts read light — excellent contrast, but the mark is only as good as the layer beneath it. On a plated or coated part, the mark has to cut through the coating, and stating the before/after-finish order avoids a mark that is half-filled by a coating applied afterwards.
| Instruction | Why it is there |
|---|---|
| Text and punctuation | Exactly as it must read, including special characters |
| Character height | Legibility is governed by the smallest character |
| Depth | Typically 0.01–0.2 mm; deeper costs more and adds heat |
| Font | Some fonts lose strokes or open up at small sizes |
| Datum | So the mark lands where the drawing intends |
| Before / after finish | A coating applied afterwards can half-fill the mark |
Mark type against substrate
The mark you can achieve depends on what the surface already is. On bare metal the mark is the natural metal colour — a slightly darker or rougher patch than the polished surface around it, which is legible on a matte part and weak on a mirror finish. On anodized aluminium it is the strongest case, because the beam removes the anodic layer and exposes bright metal, giving high contrast in both directions. On plated steel it cuts through the deposit, and on a powder-coated part it has to cut the film.
That is the practical argument for sequencing. Where a part needs both a finish and a mark, the order decides the legibility: anodize then mark gives bright-on-anodized contrast, whereas marking then coating can half-fill the mark. Where the mark is functional — traceability, a serial, an assembly code — the sequence is an engineering decision, and it belongs on the drawing next to the marking instruction.
| Substrate / surface | Mark character | Note |
|---|---|---|
| Bare steel or aluminium | Metal colour, contrast depends on the surrounding finish | Weak on a mirror-polished surface |
| Anodized aluminium | Bright metal exposed; strong contrast both ways | The strongest laser-marking case |
| Plated steel | Cuts through the deposit to the base metal | Depth must clear the plating class |
| Powder-coated | Cuts the film to the coating or the metal beneath | Specify the order relative to the coating |
How WERIX specifies and executes it
Marking is coordinated with the finishing sequence under our specification and inspection, and it is scheduled with the other operations rather than after them by default. We specify the text, character height, font, depth and datum, and confirm the mark reads cleanly at the size on the drawing. ISO 9001 is the only management-system certification held; a laser mark carries no certification of its own, and this page does not imply one.
The judgement we apply at DFM review is legibility against cost. Depth buys character fidelity, and a mark that will be read at a distance or in poor light needs more of it than a mark read at arm's length. Telling us the reading condition — line-of-sight, scan requirement, or a human at the bench — is what makes the depth recommendation correct rather than generous.