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Can a fiber laser cut metal?

Yes – a kilowatt-class fiber laser cutter cuts metal cleanly. But fiber markers (20-100W) only mark; they don’t cut. Learn the difference and what power cuts which thickness.

Yes — if it’s a kilowatt-class fiber cutter, not a marker. Here’s the difference.

Short answer

Yes — a fiber laser is the tool for cutting metal, but only a kilowatt-class fiber cutter, not a fiber marker. Cutting steel, stainless, aluminum, brass, and copper takes roughly 1 kW and up; the 20–100 watt fiber markers people ask about only mark metal — a 30 W or 50 W fiber will not cut even thin sheet reliably. Thickness scales with power (about 10 mm stainless at 1 kW up to 20–25 mm at 6 kW). Fiber also doesn’t cut non-metals — it passes through glass and acrylic and scorches wood. For machines and thickness, see our metal-cutting guides.

Marker vs. cutter: the key distinction.

“Fiber laser” covers two very different machines. A fiber marker (20–100 W, like Boss’s FM series) etches and engraves the metal surface but cannot cut through it. A fiber cutter (kilowatt-class, like Boss’s FC series) focuses far more power and uses an assist gas to cut clean parts from sheet and tube. So a fiber laser cuts metal — if it’s a cutter.

Fiber marker versus fiber cutter: a 20 to 100 watt marker beam etches only the surface of a metal sheet, while a kilowatt-class cutter beam with assist gas cuts through it; below, cut thickness scales with power from about 10 millimeters of stainless at 1 kilowatt to 20 to 25 millimeters at 6 kilowatts
Both are fiber lasers, but a 20–100 W marker only etches the surface while a 1 kW+ cutter with assist gas cuts through — cut thickness scales with power.

Power, thickness, and non-metals.

Cutting starts around 1–2 kW for thin-to-medium sheet and scales up — roughly 10 mm stainless at 1 kW to 20–25 mm at 6 kW. A 30 W or 50 W fiber is a marker and won’t reliably cut even 1 mm stainless. And fiber only cuts metal — it passes through glass and acrylic and scorches wood. For details, see can a laser cutter cut metal?, how many watts to cut metal?, and how thick can a laser cut?

Related questions

Can a fiber laser cut metal?

Yes, if it’s a kilowatt-class fiber cutter. Fiber is absorbed by metal, so a fiber cutter slices steel, stainless, aluminum, brass, and copper cleanly with an assist gas. A fiber marker (20–100 W) only marks — it doesn’t cut.

Can a 30W or 50W fiber laser cut metal?

No — those are marking wattages. A 30 W or 50 W fiber etches and engraves the metal surface but cannot cut through it; it won’t reliably cut even 1 mm stainless. Cutting needs a kilowatt-class fiber cutter.

Can a 50W fiber laser cut 0.8mm or 1mm stainless steel?

Not reliably. A 50 W fiber marker is built to mark, not cut, so even thin 0.8–1 mm stainless is beyond it for clean, repeatable cutting. For thin sheet you want at least a ~1 kW fiber cutter.

How do you cut 1-inch or thicker metal with a fiber laser?

Thick metal needs high power — roughly 6 kW handles around 20–25 mm (about 1 inch), and the largest industrial systems (12 kW and up) cut thicker. Pair the power with the right assist gas and settings for the metal. See our metal-cutting thickness guide.

Will a fiber laser cut non-metals?

No. Fiber is for metal — its wavelength passes through glass and clear acrylic and scorches wood, so it doesn’t cut non-metals. Use a CO2 laser for wood, acrylic, leather, and paper.

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