How to Pick the Best CNC Laser Marking Machine for Your Parts
This guide is for engineers and buyers who need permanent part IDs, not decorative engraving. Read it to judge laser type, mark depth, cycle time and supplier capability before you request a quote.
In this article
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Key takeaways
Laser type selection by material and mark
Use the row that matches your part. If two rows fit, run samples on both.
| Laser | Best on | Typical mark | Watch out for |
|---|---|---|---|
| Fiber 1064 nm | Steel, stainless, aluminum, brass, titanium | Annealing, shallow engraving, deep engraving | Slight heat tint on thin walls |
| Fiber, high power | Tool steel, Inconel, carbides | Deep engraving 0.1–0.3 mm | Slower cycle, more dross at edges |
| CO2 10.6 μm | ABS, PC, PMMA, painted and coated surfaces | Surface melt or removal of coating | Poor contrast on bare metal |
| UV 355 nm | PEEK, nylon, anodized layers, thin films | Cold ablation, fine contrast | Low depth, needs a clean surface |
| Green 532 nm | Copper, gold, heat-sensitive parts | Fine surface marks | Higher cost per part |
| Fiber + rotary | Shafts, rings, cylinders Ø up to 400 mm | Marks around a diameter | Chuck jaw marks if not padded |
What to put in the RFQ so quotes compare
Quotes that answer these points are comparable. Quotes that skip them are not.
| Item | What to specify | Why it changes the price |
|---|---|---|
| Material and temper | 6061-T6, 316L, Ti-6Al-4V, PEEK | Laser absorption differs by alloy |
| Pre-mark surface | As machined, Ra 0.8–1.6 μm, bead blasted | Roughness changes contrast and depth |
| Post-mark finish | Clear anodize, black oxide, none | Mark may be buried by coating |
| Mark content | Text, logo, Data Matrix, serial | Vector data marks faster than raster |
| Depth and tolerance | 0.03–0.06 mm, measured | Depth drives cycle time |
| Character height | 1.5 mm minimum | Smaller type needs a different lens |
| Quantity and MOQ | 1 prototype to 10,000+ parts | Setup is amortized over the run |
| Traceability | Serial list, inspection report | Data handling adds process steps |
The short version
Pick the laser by material and mark depth, not by wattage. Prove the mark on your real surface and finish before you commit to the run, and put the datum and fixture in the quote so the mark lands where the drawing says.
What a CNC laser marking machine actually does
A CNC laser marking machine moves a focused beam over a fixtured part along a programmed path. The beam changes the surface rather than cutting through it. Depending on power, frequency and scan speed, you get an annealed color change, a shallow engraved groove, or a deep recess. Nothing touches the part, so there is no tool wear and no clamp load on a finished surface.
For a machine shop, the value is placement. The same axes that milled the part can position the mark using the same datum. A hole pattern and a serial number land in one coordinate system, so the mark stays where the drawing says even when the part is re-fixtured for a second operation.
Depth control comes from power density and pass count, not from a single number on a datasheet. A 20 W fiber source marking at 0.02 mm depth and a 50 W source marking at 0.2 mm both work; they just take different times. That trade is the core buying decision.
The mark is also a record. Once a serial, lot code or Data Matrix is burned into the surface, it survives degreasing, anodizing, plating and shipping. That is why traceability requirements push marking back into the machining cell instead of a separate station.
Choosing between laser marking and laser engraving
Marking and engraving are often used as one word, but they behave differently. Marking changes the surface: annealing on stainless, a color shift on anodized aluminum, a matte patch on a coated part. Engraving removes material and leaves a groove you can feel with a fingernail.
Pick marking when the part will be anodized or painted after the operation, when wall thickness is thin, or when you need a fast cycle on a high-volume run. Annealed marks on stainless are corrosion-tolerant and do not create a crevice where salt spray can collect.
Pick engraving when the mark must survive a later machining pass, tumbling, shot blasting or grinding. A 0.1 mm groove still reads after 0.05 mm is skimmed off the face. A surface mark does not.
There is a middle path. A shallow engraving of 0.03–0.05 mm gives contrast on bare aluminum and still finishes quickly. It is the common choice for part numbers and revision codes on machined housings.
- 1Mark first, finish laterAnodizing and powder coating cover a surface mark. Sequence matters.
- 2Engrave before final grindLeave enough depth so the mark stays legible after stock removal.
- 3Check contrast, not just depthA deep mark on a dark material can read worse than a shallow one.
Buying checks for a CNC laser marking machine supplier
The laser source is only part of the decision. Ask how the mark is positioned. If the supplier can mark on the same 5-axis setup that machined the part, you avoid a second fixture and the stack-up error that comes with it. GreatLight runs 16 simultaneous 5-axis machining centers, so a mark can be placed before the part leaves the cell.
Ask for a sample on your material and finish. Send a part or a blank with the real surface condition. A mark that reads well on bare 6061 aluminum may vanish under black anodizing. Test the exact finish you will ship.
Ask about depth measurement. A shop that controls depth uses a profilometer or a calibrated microscope, not a visual check. Depth tolerance should be stated as a range, for example 0.03–0.06 mm, with a report on request.
Check the certification set against your industry. ISO 9001:2015 covers general quality systems. IATF 16949:2016 matters for automotive and EV parts, ISO 13485:2016 for medical devices, and ISO 27001:2022 for how your drawings and serial data are stored.
Finally, ask about character limits. Minimum character height is 1.5 mm in our process. Below that, the mark may pass a visual check on the bench and fail a scanner audit in the field.
Common mistakes that cost parts and time
The most expensive mistake is ordering the mark after the finish. A clear anodize layer is only a few micrometers thick, but it scatters enough light to drop contrast on a shallow mark. If the drawing shows a mark under a coating, the engraving depth has to be set with the coating in mind.
The second is ignoring the datum. A mark placed from a vise jaw instead of the part datum moves when the operator re-clamps. On a part with a 0.05 mm position callout, that is enough to fail. Fixture design belongs in the quote, not in the shop floor improvisation.
The third is testing on the wrong surface. A shop that proves a mark on a polished coupon and then marks a bead-blasted production part will see a different result. Bead blasting diffuses the beam and lightens the mark on aluminum.
The fourth is chasing depth for its own sake. Deep engraving takes seconds per part and can warp thin walls. If the requirement is readability after cleaning, a controlled shallow mark usually passes and ships faster.
When laser marking is the wrong answer
If the part will be coated with a thick powder coat, a laser mark under the coating will not read. In that case mark after coating, or use a masked area and a different process. Tell the supplier which layer is on top.
If the surface is a mirror polish on a visible face, any mark changes the appearance. Move the mark to a hidden face or accept that the part is no longer cosmetic. Laser marking is not reversible.
If the material is a soft plastic that melts rather than ablates, a CO2 or UV source can leave a raised burr. Test before committing to a production run.
If the quantity is one part and the requirement is a handwritten tag, laser marking adds setup for little gain. It pays off when the mark must survive the service life of the part.
From RFQ to marked parts in five steps
This is the sequence we follow on a marking job, including the checks that catch problems early.
- 11. Review the drawing and the finish sequenceWe confirm material, pre-mark surface, post-mark finish and the datum the mark is dimensioned from. A DFM note comes back within 12 hours, including free analysis of anything that will not mark cleanly.
- 22. Prove the mark on your materialWe mark a test piece at two or three power and speed settings and measure depth. For stainless we compare annealing against a 0.03 mm engraving. You get the sample data before the run starts.
- 33. Fix the fixture and the positionThe mark is programmed from the same datum as the machining operation. On 5-axis parts we mark in the same setup, so there is no second clamp and no stack-up.
- 44. Run production with in-process checksCharacter height stays at or above 1.5 mm. Depth is held to the agreed range, typically 0.03–0.06 mm for a shallow mark or 0.1–0.3 mm for a deep one. Operators check contrast and legibility at the machine.
- 55. Inspect and document before shipment100% inspection before shipment covers mark presence, position and legibility. Serial lists and depth reports are available on request. Production can start within 24 hours and parts ship in 3–5 days.
Questions buyers ask before ordering
Which materials can a CNC laser marking machine mark?
Most metals mark well with a fiber source: stainless 303 and 316L, aluminum 6061 and 7075, titanium Ti-6Al-4V, brass C36000 and copper C110. Plastics such as ABS, PC, POM, PA and PEEK mark with CO2 or UV. Ceramics, glass and carbides are also workable.
Material behavior, not just material name, decides the settings. A 316L part and a 303 part need different power and speed to reach the same contrast.
How deep should a laser mark be for traceability?
For a readable surface mark on stainless or aluminum, 0.02–0.05 mm is enough. If the mark must survive a later skim, tumbling or grinding, go to 0.1–0.3 mm.
Depth is measured, not guessed. Ask for a depth range and a report so the mark can be verified against the drawing.
Will the mark survive anodizing or plating?
An annealed or engraved mark on aluminum usually survives clear anodize, though contrast may drop. A mark applied before a thick powder coat or a heavy plating layer may be buried.
The safe sequence is to mark after the coating, or to specify a mark depth that accounts for the coating thickness. Send the exact finish in the RFQ.
What is the smallest character a laser can mark?
Our process floor is 1.5 mm character height. Below that, characters can still be produced but legibility after finishing and handling becomes a risk.
If your drawing calls for 0.8 mm text, discuss it early. A different lens and a flatter surface may help, but the mark may not pass a scanner audit.
Does laser marking slow down a machining job?
A shallow mark adds a few seconds per part. Deep engraving can add much more, and on a 10,000-part run that changes the price.
Marking inside the machining cycle, on the same 5-axis setup, avoids a second fixture and a second setup, which usually saves more time than the mark itself costs.
What do you need to quote a marking job?
Send the 3D model or drawing, the material and temper, the pre-mark surface condition, the post-mark finish, the mark content and the quantity. Add any depth, character height and traceability requirements.
With those details, quotation and free DFM analysis come back within 12 hours. No minimum order quantity applies, from one prototype to 10,000+ parts.
Send a part, get a proven mark
Upload your drawing and surface spec. We will return a quote, a DFM note and a marking recommendation within 12 hours.
12-hour quoteNo minimum order quantity100% inspectionNDA on request
More from the shop floor
We publish setup notes, tooling trials and inspection data from the factory floor.
