CO2 vs Fiber for Metal Engraving: What Actually Cuts Metal?

I review laser systems before they're allowed to ship to customers. Part of my job is saying "no" to things that look great in a demo but won't survive a production run.

So when someone types "what cuts metal" into Google and lands on my desk, I get it. The answer depends on what kind of metal—and what you mean by "cuts." That's exactly what I want to break down here.

The comparison: CO2 vs fiber for metal work

Two laser technologies dominate this space. CO2 lasers are the workhorses of wood, acrylic, and plastic processing. Fiber lasers are the go-to for bare metal marking and thin-metal cutting. But there's more nuance than that, especially if you're looking at a brand like Trotec.

I'm going to compare them the same way I'd compare two suppliers in a quality audit: material capability, cutting vs engraving, total cost of ownership, and consistency. No hype, just what I'd check before signing off.

Dimension 1: What each laser can actually process

CO2 lasers emit at 10.6 µm—a wavelength that organic materials love to absorb. Wood, paper, leather, acrylic? They all take a CO2 beam beautifully. Bare metal, though? Not so much. Reflective metals like aluminum and copper tend to reflect the beam instead of absorbing it, which is risky for both the workpiece and the machine.

Fiber lasers operate at ~1.06 µm, and that wavelength is readily absorbed by metals. You can mark stainless steel, brass, aluminum, titanium—bare, clean, no coating needed. That's the simple answer to "what cuts metal": a fiber laser, usually.

But here's the part that surprises a lot of buyers: CO2 lasers can handle some metal jobs. Specifically, coated metals. Anodized aluminum, painted steel, powder-coated surfaces—the beam vaporizes the coating and exposes the substrate, leaving a permanent mark. I've personally tested a Trotec Speedy CO2 machine that marked anodized aluminum with outstanding contrast. So if someone tells you CO2 lasers can't touch metal, they're oversimplifying.

Before you compare prices, look at the official trotec laser materials guide. It shows which materials are approved for each system—and which ones will damage your optics or void your warranty.

Real-world laser cutter examples

• CO2 laser cutter: acrylic signage, wood crafts, leather engraving, paper cutting, marking anodized aluminum.
• Fiber laser: engraving serial numbers on steel, cutting thin stainless sheets, marking aluminum without pre-coating.
• Diode laser (hobby/semi-industrial): engraving wood, leather, dark plastic—but for metal? Only certain coated surfaces, and often too slow for production.

Dimension 2: Cutting vs engraving—they're not the same

I keep a clear distinction in my head: cutting means going all the way through. Engraving or marking means removing a layer or changing the surface color. The machine you need depends on which one you actually want.

If you're cutting 0.5 mm stainless steel for nameplates, a fiber laser can do it at a reasonable speed. A CO2 laser like the Trotec Speedy 100? It's not the right tool. It's designed for fine cutting and engraving of non-metals. Cranking up a CO2 tube to try to cut bare metal will give you a burned edge at best, and a damaged machine at worst.

Not ideal, but a necessary simplification.

Dimension 3: Trotec Speedy 100 price vs long-term fiber cost

Let's talk about search phrases for a moment. "Trotec laser speedy 100 price" gets a lot of hits. The Speedy 100 is an approachable entry point into Trotec's ecosystem, and it's a smart starting point if you're primarily working with non-metals. But if I'm doing a quality inspection on a capital purchase, I always calculate total cost of ownership, not just the sticker price.

The lowest quoted price often isn't the lowest total cost. Total cost includes the base unit, software licensing, optics maintenance, replacement tubes, training, and downtime if the system goes down.

Here's the thing: Trotec pricing is quote-based. I can't give you a universal number as of early 2025—market conditions and configurations change too quickly. But I can tell you what moves the price: laser wattage, work area size, laser type (CO2, fiber, or dual-source Flexx), and options like autofocus or camera systems.

And here's the unexpected twist in this comparison: a CO2 machine like the Speedy 100 can have a lower upfront price than a comparable fiber laser—but for metal-heavy workflows, the fiber laser often wins on cost-per-part over time. Fiber lasers have fewer consumables, longer service intervals, and no expensive gas-filled laser tube to replace. If your whole job is marking bare metal, a fiber machine will likely pay for itself in throughput and maintenance savings.

Dimension 4: Consistency—where I earn my paycheck

From my role, the most important dimension is consistency. Can the machine produce the same depth, the same contrast, and the same edge quality across a production run of 50,000 parts? That's where the flashy demo often fails.

I remember a vendor claiming their CO2 machine could cut 1 mm stainless steel "with no problem." We tested it. The first few passes looked okay. By the tenth part, the edge quality degraded and the tube temperature was climbing. That wasn't a manufacturer defect—it was a physics problem. Wrong wavelength, wrong power budget, wrong machine for the application.

To assess quality, we use principles similar to print standards. For engraved logos, we check line resolution—at least 300 DPI equivalent for crisp edges, just like commercial print. For color matching on anodized aluminum, we use a physical reference standard, similar in spirit to a Pantone swatch, to agree on what "black" or "gold" should look like before we accept a batch.

What I've learned: don't assume a machine that works for one material will work for another. Check the specs, run the test, measure the output. And if a salesperson says "it can do everything," that's a red flag.

So which one should you choose?

If you're still asking "what cuts metal," let me answer it scenario-by-scenario instead of with a blanket statement.

Choose a CO2 laser (Trotec Speedy series) if:

• Your work is 80%+ wood, acrylic, leather, or paper.
• You occasionally mark anodized aluminum or coated steel.
• You want a flexible engraver/cutter for a sign shop or small-scale production.
• The trotec-laser Speedy 100 price fits your startup budget.

Choose a fiber laser (Trotec Fiber series) if:

• You mark bare metals daily—steel, aluminum, titanium, brass.
• You need thin metal cutting (generally under 2 mm for practical production).
• You're buying an industrial laser etching machine for serializing parts, traceability, or permanent markings.
• Low operating costs and high uptime matter more than low initial price.

What about a diode laser?

Diode lasers are cheap and popular for hobby setups. They're fine for wood and leather, but for industrial metal work? In my experience, they're almost never a true replacement for CO2 or fiber. They lack the power density and beam quality for reliable production. If you're a professional, treat diode as a prototyping tool, not a production solution.

The bottom line

I'd rather spend ten minutes explaining these options than deal with a customer who bought the wrong machine and then blames the technology. An informed customer asks better questions and gets a system that actually matches their workflow. That's the outcome I care about.

So, CO2 or fiber—what cuts metal? Fiber for bare metal, CO2 for coated metal, and neither is a universal answer. Know your material, your tolerances, and your total cost. Then you'll know which side of this comparison deserves your budget.