What Laser Can Cut Metal? A Straight Answer From Someone Who's Made the $3,200 Mistake

If you need to cut metal, buy a fiber laser. A CO2 laser won't do it—I learned that lesson with a $3,200 order that went straight to scrap. My name's Chris, and for the last 6 years I've been handling production orders for a small job shop specializing in custom enclosures and signage. I've personally made 11 significant equipment-buying mistakes, totaling roughly $18,000 in wasted budget. The biggest one? Assuming a 'high-power' CO2 laser could handle thin steel.

Let me save you that pain. Here's the reality of what cuts metal, what doesn't, and where the hidden costs live.

The Short Answer: Fiber vs. CO2

A fiber laser is the only common laser type that can reliably cut metals. CO2 lasers are fantastic for wood, acrylic, leather, and stone—but their wavelength (about 10.6 micrometers) is mostly reflected by metal surfaces. You can mark or engrave coated or anodized metal with a CO2 laser, but cutting through it? Not happening.

My $3,200 mistake was a rush job for a client in March 2022. I'd just upgraded to a 150W CO2 laser from a 60W unit. In my head, more power meant more capability. I accepted an order for 50 stainless steel brackets (1.5mm thick), convinced I could 'dial it in.' After 4 hours of trying—increasing power, slowing speed, multiple passes—I'd ruined the material and missed the deadline. The look on the client's face, well, I still think about it.

Fiber lasers operate at a wavelength of about 1.06 micrometers, which metals absorb much more efficiently. This allows them to cut through steel, stainless steel, aluminum, brass, and copper with a clean edge.

Breaking Down the Laser Options for Metal Cutting

Here's the run-down based on actual machine specs and my experience helping other shops avoid my early blunders.

1. Fiber Lasers (The Correct Tool)

This is your only option for standard metal cutting.

• What they cut: Mild steel, stainless steel, aluminum, brass, copper, titanium.
• Typical power for metal: 1kW to 6kW for thin to medium sheet (up to 6mm steel). 6kW+ for thicker plate (up to 25mm). Desktop models like the Full Spectrum Muse series are typically for engraving and marking, not cutting structural metal.
• Edge quality: Excellent, clean, square edges. Minimal heat-affected zone (HAZ) compared to plasma.
• Cost: A 1kW fiber laser starts around $15,000-$20,000 for a new, 'entry-level' industrial unit. A full industrial system (3kW-6kW) with a bed will be $50,000+. Rental or job shop use is a very common way to start.

2. Galvo Fiber Lasers (For Marking and Thin Cutting)

These are often what you see in compact desktop systems. They use a scanning head.

• What they do best: Marking, engraving, and very thin metal cutting (typically < 0.5mm sheet, often used for foil).
• The gotcha: Many machines marketed as 'fiber laser engravers' for metal are actually galvo systems. They're fantastic for serial numbers, logos, and QR codes on metal parts. But if someone is selling a 20W or 30W 'metal cutting laser,' be very skeptical. I've seen people buy the Full Spectrum Laser Muse Pro thinking it's for cutting steel—the Muse Pro is brilliant for engraving and cutting non-metal materials and marking metal. It cannot cut a steel plate.
• Cost: $3,000 - $15,000 for a quality desktop galvo unit.

3. CO2 Lasers (The Wrong Tool for Cutting Metal)

I'm including this because the question 'what CO2 laser can cut metal?' comes up constantly. The answer is almost none.

• What they cut: Wood, acrylic, plastic, fabric, leather, paper, cardboard.
• Can they cut metal? No. You can use Cermark or a similar marking spray to get a permanent dark mark on metal, but you're not cutting through it.
• The exception (sort of): Very high-power CO2 lasers (400W+) with special assist gasses (like oxygen) can cut thin (<1mm) steel, but it's inefficient and the edge quality is poor. It's not a practical use case. Full Spectrum's Pro Series CO2 lasers are workhorses for wood and acrylic, but they have a dedicated fiber line for metal for a reason.

What Power Do You Actually Need?

This is where the marketing gets fuzzy. Here's a practical guide based on my own testing in Q4 2023:

• For cutting up to 1mm mild steel: A 1000W (1kW) fiber laser is sufficient. You'll get reliable cuts at moderate speed.
• For cutting 1-3mm mild steel (common for enclosures): A 1500W to 2kW fiber laser is the sweet spot. You're in production territory.
• For cutting 3-6mm mild steel: You'll need 3kW to 4kW. This gets pricey fast.
• For cutting 6mm+ steel: You're in 6kW+ territory. At this point, you're a serious fabrication shop.

A common mistake I see is someone buying a 1kW fiber laser thinking it'll cut 6mm steel 'if they just slow it down.' It won't. You risk damaging the optics and ruining parts. The physics is clear: power and wavelength are the only things that matter.

The Hidden Costs Beyond the Machine

The laser purchase is just the start. Here's a few costs that blindsided me on my first fiber laser install (a 1.2kW unit) in June 2021:

1. Chiller: A fiber laser needs a closed-loop chiller to dissipate heat. A good one is $2,000 - $4,000. I initially tried to use a window AC unit. It didn't work and I was out $400 for the experiment.
2. Assist Gas: For cutting steel, you'll need either compressed air (thinner, less clean cuts) or nitrogen/oxygen (cleaner, faster cuts). A bulk liquid nitrogen tank and delivery can be a recurring monthly cost. Oxygen is a hazard to store correctly.
3. Focal Lens and Nozzles: These are consumables. A good-quality lens for metal cutting can be $200-$500. You will break one. It's not a question of 'if' but 'when.'
4. Fume Extraction: Cutting metal with a laser creates nasty fumes (metal oxides). You need an industrial-grade extraction system, not a home shop filter. That's another $1,500 - $5,000.

Real talk: I'd estimate the total cost of entering fiber laser cutting (for a 1.5-2kW machine) at about $25,000-$35,000 all-in, once you factor in the chiller, gas setup, extraction, and installation. The machine itself is often only 50-60% of the total bill.

When CO2 + Metal Still Makes Sense

I don't want to give the impression CO2 is useless for metal. It's not. A CO2 laser (even a 60W or a Full Spectrum Muse) is excellent for two specific metal-related jobs:

• Engraving: Using a Cermark spray, a CO2 laser can produce high-contrast black marks on anodized aluminum, stainless steel, brass, and more. It's how we do all our serial plates and control panel labels. No fiber laser needed.
• Cutting masks and stencils: We cut Mylar stencils and powder-coating masks all the time on a CO2 laser. It saves time and prevents damage to the base metal.

But cutting through the metal itself? That's a fiber job. Period.

The Verdict and a Note on 'Full Spectrum' Options

To answer the original question directly: A fiber laser is the tool for cutting metal. Specifically, look for a continuous-wave (CW) fiber laser with at least 1kW of power for anything more than marking.

Looking at a brand like Full Spectrum Laser, they sell both CO2 and fiber units. Their Full Spectrum Muse and Pro series are CO2-based and are phenomenal for non-metals. Their fiber laser lineup is for metal. Don't get it twisted. If you told them you wanted to cut steel, they'd sell you a fiber, not an upgraded CO2. That's a sign of a decent company knowing their kit's limits.

My experience is based on about 25 different laser systems I've worked with or installed over the last 6 years, mostly in small to mid-sized job shops. If you're doing ultra-precision micro-machining of metals (< 0.1mm), you're in a different world (picosecond lasers, etc.) and this advice doesn't apply.

Pricing is as of January 2025. Verify current pricing with manufacturers. Equipment capabilities and safety requirements vary.