Laser marking vs engraving vs etching for EDC logos and serial numbers

Three words used as synonyms in RFQs, describing three processes with different depths, different costs and different interactions with your finish. Getting the sequence wrong is how a clean anodized part ends up with a raw metal scar through the logo.

Laser marking

The laser changes the surface without removing meaningful material — oxidising it, annealing it, or foaming it depending on the material and settings. Depth is measured in microns.

On steel and titanium: annealing produces a dark, smooth mark with no depth. It is the cleanest look available and it does not disturb a subsequent finish.

On anodized aluminium: the laser ablates the dye and reveals the substrate, producing a light mark on a dark part. This is how most flashlight body text is done, and it is done after anodizing.

Cost: lowest of the three, and it scales well — once the program is set, marking 500 parts is fast.

Laser engraving

The same machine, more power, material actually removed. Depth typically 20 to 500 microns. You can feel it with a fingernail.

Use it when: the mark must survive wear, or when you want a tactile logo, or when the mark will be filled with paint or enamel.

Watch for: engraving through a thin wall, and heat affected zone on very small features. Also, an engraved mark on a part that is subsequently bead-blasted will soften noticeably.

Chemical etching

Masked and chemically removed rather than lasered. Shallow, very crisp, and excellent for fine detail or large flat areas.

Use it when: you need very fine line work, or a large marked area, or you are marking a material that lasers poorly.

The catch: it needs a mask per design, which is a tooling cost. It makes sense at volume, rarely at 50 pieces.

The sequencing question

This is where EDC projects go wrong. The rule depends on the finish:

Anodized aluminium: mark after anodizing. The laser removes the dye to create contrast. Marking before means the mark disappears under the coating or the anodize grows unevenly over the disturbed surface.

Anodized titanium: usually mark before anodizing, so the colour flows over the mark and it sits flush under the finish. Marking after leaves a bare metal scar — occasionally the desired effect, usually not.

Stonewash or bead-blast: mark after. Blasting a marked part softens the edges of the mark; a deep engraving survives, a shallow marking does not.

PVD: mark before, and accept that the coating will slightly round the edges of fine detail.

If you are not sure, say on the drawing what you want the finished mark to look like and let the shop sequence it. That is a better instruction than naming a process.

Serial numbers and variable data

If each part gets a unique number, say so explicitly and give the format and the range. Variable marking is a different program setup from a fixed logo and it needs part handling that keeps the sequence intact. It is not expensive, but it is not free, and it is annoying to add after quoting.

For limited editions, decide early whether the number is sequential in production order or assigned later — the second requires you to track which physical part got which number, which means individual packing.

Artwork

Send vector: SVG, AI, EPS or DXF. A PNG of your logo will be traced by someone else and the result will not be quite your logo. Include the intended size in millimetres and the position relative to a feature on the part, not “centred on the face” — centred on which face, measured from where?

What to write

Process intent, sequence relative to finish, artwork as vector, size, position, and whether data varies per part. Send it with the drawing rather than as a follow-up email. Related: finishes that survive a pocket.

Which laser for which material

Not all lasers mark all materials, and this determines which shops can do your job in-house.

Fibre laser (1064 nm). The workhorse for metals. Marks and engraves steel, titanium, aluminium and brass. Anneals steel and titanium to a dark mark without depth. This is what almost every EDC part is marked with, and most machine shops that do any marking have one.

CO2 laser (10.6 micrometres). Good on organics — G10, micarta, wood, leather, acrylic. Will not mark bare metal usefully. If your scales are micarta and your hardware is titanium, those are two different machines.

UV laser (355 nm). Cold marking with very little heat input, excellent for fine detail and for plastics that would melt under a fibre laser. Less common, higher cost.

If your product combines metal and composite scales, ask which machines the shop has rather than assuming one covers both.

Colour marking on stainless and titanium

A fibre laser can produce colour on stainless and titanium by growing a controlled oxide layer — the same interference physics as titanium anodizing, applied locally by the beam.

It allows a coloured logo without a masking and anodizing step, and it is genuinely striking. Two caveats: the colour range is narrower than bath anodizing, and repeatability across a batch requires a well-calibrated machine. Ask for samples.

Depth, and what it costs

Marking is effectively free once programmed — a few seconds per part. Engraving is priced by material removed, so depth costs time roughly linearly.

A 0.05 mm engraving might take fifteen seconds. The same logo at 0.5 mm takes ten times as long and needs multiple passes. If you want a tactile logo, specify the shallowest depth that achieves it — 0.1 to 0.2 mm is usually enough to feel.

Fill and infill

An engraved mark can be filled with paint, enamel or epoxy for contrast. It is a manual operation, priced per part, and it needs an engraving deep enough to hold the fill — typically 0.15 mm minimum.

Budget for a reject rate. Fill operations on small logos are fiddly and some will be wiped, smeared or uneven.

Positioning and fixtures

A mark has to be located relative to the part, which means a fixture that holds every part in the same place.

For a flat part, a simple plate with locating pins is trivial. For a cylindrical body that needs the logo on a specific facet relative to a thread start, the fixture is a real piece of work and it is a legitimate line on the quote.

Say on the drawing what the mark is located from. “Centred on the clip face, 12 mm from the pivot bore centre” is a specification. “Centred” is not.

Marking and the finishing sequence, summarised

Finish	Mark when	Result
Anodized aluminium	After	Light mark on dark part
Anodized titanium	Before	Colour flows over, flush
Bead-blast	After	Crisp; blasting softens a mark
Stonewash	After, deeper	Tumbling rounds shallow marks
PVD	Before	Coating slightly rounds fine detail
Bare metal	Either	Anneal marking preferred for contrast

Regulatory and traceability marking

If you sell into markets requiring country-of-origin marking, or you want lot traceability for warranty, plan it now rather than later.

A small lot code marked alongside the logo costs nothing extra and lets you identify which batch a returned part came from. For a brand that has ever had a finish problem on one production run, that information is worth a great deal.

FAQ

Will laser marking wear off? Annealed marks on steel and titanium are extremely durable because the mark is in the surface, not on it. Marks that ablate anodize are as durable as the surrounding anodize. Engravings are effectively permanent.

Can I mark a serial number the customer can read easily? Yes, but consider size — small text on a curved surface is hard to read. A 2 mm character height is about the practical minimum for unaided reading.

What file format for the logo? Vector: SVG, AI, EPS or DXF. Include the intended size in millimetres. A raster logo will be traced and the result will differ subtly from your brand mark.

Can very small text be marked? Fibre lasers resolve well below 1 mm character height. Whether it is legible is a different question from whether it can be marked.

Does marking affect corrosion resistance? Slightly, on stainless — the marked area’s passive layer is disturbed. Passivate after marking if corrosion matters. See passivation.

Should the mark be on the show side? A branding decision, but note that a mark on a surface that rubs in a pocket will wear faster. Many brands mark the lock side for that reason. Say where you want it with the drawing.