The short answer: engraving bare metal needs 1064 nm, which means a fiber or infrared laser. The ComMarker B4 30W is the best value, the xTool F1 Ultra is best if you also engrave wood, and the xTool F2 Ultra is the one that marks stainless in colour. No blue diode engraves bare metal, whatever the listing claims.
The ComMarker B4 had only a handful of Amazon reviews at the time of writing, too few to read anything into either way. Check the current listing before buying.
This is the most expensive mistake in the hobby, and it is made weekly. A listing says “metal engraving” next to a 20 W blue diode; the buyer means stainless tumblers; the machine means powder-coated tumblers. They are not the same thing.
Why wavelength decides everything
Bright metals reflect visible light — that is what makes them shiny — and a blue diode emits visible light at about 455 nm. Metal absorbs infrared at 1064 nm far more readily, which is why fiber and infrared lasers mark it and diodes do not.
| Metal | Blue diode 455 nm | Infrared 2–3 W | Fiber 20–60 W |
|---|---|---|---|
| Stainless steel | Nothing on bare steel | Dark annealed mark | Deep engrave; colour with MOPA |
| Anodised aluminium | Removes dye — white mark | Clean white mark | Fast and deep |
| Bare aluminium | Nothing | Faint grey | Proper engraving |
| Brass & copper | Nothing | Marginal | Yes; copper wants more power |
| Titanium | Nothing | Oxide colour | Full colour range with MOPA |
| Powder-coated | Excellent | Yes | Yes |
ComMarker B4 30W Fiber
A galvo fiber laser for the price of a mid-range diode. 110 mm square field, which suits knives, tags, rings and tumbler panels and rules out anything large. Electric focus column, and LightBurn talks to it so you are not locked into EZCAD.
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xTool F1 Ultra
Fiber head and diode head in one body. Stainless tags and basswood ornaments on the same bench with no module swap. For a mixed product line this is cheaper and smaller than owning two machines.
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xTool F2 Ultra
60 W MOPA. Adjustable pulse duration is what produces colour on stainless — a capability you can put on a price list. It also cuts around 2 mm brass, stainless and aluminium outright. LightBurn works with it from version 2.2.0, according to xTool’s October 2026 Q&A.
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LaserPecker LP4
Infrared and diode in a handheld head. For markets and on-site personalising, being able to mark a customer's own flask in front of them is worth more than bench speed.
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Field size is the spec people get wrong
Galvo machines mark inside a fixed square — commonly 110 × 110 mm or 150 × 150 mm. That sounds tiny next to a 400 mm diode bed, and for flat work it is. For cylinders it does not matter at all, because the rotary turns the work rather than the beam travelling. Match the field to your largest flat part, not to your biggest ambition.
Questions people also ask
What is the best laser engraver for metal?
For value, the ComMarker B4 30W fiber. For a mixed wood-and-metal shop, the xTool F1 Ultra. For colour marking on stainless and cutting thin metal, the xTool F2 Ultra.
Can a diode laser engrave stainless steel?
Not bare stainless. It marks powder-coated, painted or anodised surfaces, and it will mark bare steel if you apply a thermal marking spray first.
What is the difference between marking and engraving metal?
Marking changes the surface colour without removing material. Engraving removes metal to a measurable depth. Marking needs far less power, which is why 2–3 W infrared modules work at all.
Do I need MOPA for tumblers and knives?
No. Standard fiber marks both perfectly well. MOPA matters when you want colour on stainless or very clean marks on plastics.