A Working List of Laser Cutting Materials for Engineers
This page gives a practical list of laser cutting materials and explains how each group behaves at the cut edge: which metals, plastics and non-metals cut cleanly, which need assist gas, and where the process stops making sense. Written for engineers and buyers who pick a sheet material before the first part is quoted.
What the laser does to the material
A fiber laser focuses 1,070 nm light into a spot roughly 0.1–0.3 mm wide. The metal absorbs that energy, melts locally, and a coaxial gas jet blows the molten pool out through the kerf. Nothing touches the sheet, so there is no tool wear, no clamping chatter, and no minimum corner radius forced by a cutter body.
That mechanism sets the first rule of any list of laser cutting materials: the material must absorb the beam, and the molten pool must flow out cleanly. Steel, stainless and aluminium do both. Copper and brass reflect most of the beam at room temperature, so they need higher power and a tighter focus before the cut stabilizes.
Reflectivity is not fixed. It drops once the surface starts to melt. That is why a 1 kW fiber laser struggles with 3 mm copper but a 6 kW source cuts it without drama. Power, not material name, decides whether a sheet is cuttable.
Heat also has to go somewhere. A narrow kerf leaves a heat-affected zone (HAZ) of roughly 0.05–0.3 mm on most steels. On thin sheet that is negligible. On 12 mm plate it can change hardness at the edge, which matters if the part is later welded or fatigue-loaded.
- 1AbsorptionThe surface must take in 1,070 nm light, not bounce it back.
- 2Melt flowAssist gas must push the molten pool out of the kerf.
- 3Heat pathThick sections hold heat longer and widen the HAZ.
Ferrous metals on the list
Carbon steel is the easiest entry on any list of laser cutting materials. Grade 1018 or A36 cuts with oxygen assist, and the oxygen reaction adds heat, so 6 mm plate cuts faster than it would with nitrogen. The trade-off is a slightly oxidized edge that needs cleaning before paint or weld.
Switch to nitrogen assist and the edge comes out bright and oxide-free, ready for powder coating. You pay for the gas and lose some speed, but you skip a secondary operation. For brackets, covers and weldments that get painted, that is usually the right call.
Stainless steel 304 and 316 need nitrogen, not oxygen. Oxygen assist on stainless leaves a heavy dark oxide that is hard to remove and can seed corrosion. With nitrogen at 12–18 bar, 3 mm 304 cuts at roughly 4–6 m/min on a mid-power fiber machine and the edge stays silver.
Tool steel and 4130/4140 behave well up to about 10 mm. Beyond that, dross starts to hang on the bottom edge and the kerf tapers. If the part needs a straight, burr-free edge at 15 mm, laser is the wrong process; waterjet or abrasive cutting will serve you better.
- 1Carbon steelOxygen for speed, nitrogen for a clean weld edge.
- 2Stainless 304 / 316Nitrogen assist only, or the edge oxidizes.
- 3Alloy steelClean to about 10 mm; dross appears past that.
Aluminium, copper and titanium
Aluminium is on the list, but it is not the same animal as steel. The surface reflects, and the metal conducts heat away about five times faster than steel. Both effects push you toward higher power and nitrogen assist. A 6 kW source cuts 6 mm 6061 cleanly; 3 mm cuts on almost any modern fiber machine.
Alloy choice matters more than thickness. 5052 and 6061 cut predictably. 7075 has a higher zinc content and tends to micro-crack at the edge when cut with a cold, fast pass. If a 7075 bracket will see fatigue loads, plan a light machining pass on the cut face.
Copper and brass sit at the hard end of the list. C110 copper reflects strongly and needs 4–6 kW for 3 mm. Brass C36000 is easier because the zinc vaporizes and helps the kerf clear, but the zinc vapor is toxic, so fume extraction is not optional.
Titanium (Ti-6Al-4V, grades 2 and 5) cuts well with argon or nitrogen assist. The concern is not the cut, it is the edge chemistry. Titanium reacts with oxygen at high temperature, so a nitrogen-shielded cut keeps the edge ductile. Leave the oxide on and the part can fail a bend test.
- 1AluminiumHigh reflectivity and fast heat sink; nitrogen, high power.
- 2Copper / brassNeeds 4–6 kW; zinc fume must be extracted.
- 3TitaniumArgon or nitrogen shield keeps the cut edge ductile.
Plastics and other non-metals
CO2 lasers handle most non-metals; fiber lasers generally do not. Acrylic (PMMA) cuts with a flame-polished edge that needs no finishing, which is why it dominates signage and display work. ABS cuts but leaves a slightly brown edge and releases fumes, so extraction is required.
POM and PA cut cleanly at low power. PEEK is harder: it needs tighter focus and slower feed, and the cut edge stays slightly rough. Carbon-fibre sheet is a special case. The laser cuts the resin, not the fibre, so the edge frays and the dust is conductive. Many shops route or waterjet carbon fibre instead.
Wood, MDF and plywood cut well but char at the edge, and the char depth grows with thickness. Paper and cardboard cut fast and are common in packaging prototypes. Foam and rubber cut with a sealed edge, which is often the reason they are chosen over die cutting.
The rule for non-metals is simple: if the material melts without burning and the fumes can be extracted, it probably cuts. If it chars, smokes heavily, or contains chlorine (PVC), stop. PVC releases hydrogen chloride, which corrodes the machine optics.
- 1AcrylicFlame-polished edge, no secondary finishing needed.
- 2POM / PA / PEEKCut at low power; PEEK edge stays slightly rough.
- 3PVCDo not cut. Chlorine gas attacks optics and lungs.
Where laser cutting stops working
Thickness is the first wall. The practical ceiling for a 6 kW fiber source is about 20 mm carbon steel, 12 mm stainless, and 8 mm aluminium. Past those numbers the kerf tapers, dross forms, and the cut speed collapses. Waterjet or plasma becomes the cheaper route.
Edge quality is the second wall. Laser cutting leaves a striated edge on thick plate. If your drawing calls for Ra 0.8–1.6 μm on the cut face, laser alone will not reach it. A light finish pass or a different process is needed.
Material chemistry is the third wall. PVC, polyurethane foam with chlorinated blowing agents, and any sheet with a halogen content will corrode the machine. Some coated steels also release zinc or chrome fume that needs filtration. Check the material data sheet before the sheet goes on the bed.
Finally, consider what happens after the cut. Laser edges on stainless and aluminium are often weld-ready, but copper and brass leave a slightly oxidized edge that needs cleaning. If the part goes straight to anodizing, the cut edge will anodize differently from the rolled face.
- 1ThicknessTaper and dross grow fast past 20 mm steel.
- 2FinishLaser alone rarely holds Ra 0.8 μm on thick plate.
- 3ChemistryHalogen-bearing sheets corrode optics and need banning.
List of laser cutting materials at a glance
Typical ranges for a mid-power fiber or CO2 source; exact limits depend on machine power and assist gas.
| Material | Laser type | Assist gas | Typical thickness |
|---|---|---|---|
| Carbon steel 1018 / A36 | Fiber | Oxygen or nitrogen | Up to 20 mm |
| Stainless 304 / 316 | Fiber | Nitrogen | Up to 12 mm |
| Aluminium 5052 / 6061 | Fiber | Nitrogen | Up to 8 mm |
| Copper C110 | Fiber (high power) | Nitrogen | Up to 4 mm |
| Brass C36000 | Fiber | Nitrogen | Up to 6 mm |
| Titanium Ti-6Al-4V | Fiber | Argon or nitrogen | Up to 6 mm |
| Acrylic PMMA | CO2 | Air assist | Up to 20 mm |
| POM / PA | CO2 | Air assist | Up to 10 mm |
Pick the process, not the material name
If the part is flat sheet under 12 mm and needs a fast, low-tooling cut, laser is the right call. If it needs a mirror finish, tight tolerance on the cut face, or a thickness past 20 mm, choose waterjet or CNC machining instead. Send us the drawing and we will tell you which one fits.
Common questions
Can a fiber laser cut copper and brass?
Yes, but only at higher power. Copper C110 reflects most of the 1,070 nm beam when cold, so 3 mm needs roughly 4–6 kW and a tight focus. Brass C36000 is easier because zinc vaporization helps clear the kerf.
Zinc fume is toxic. Any shop cutting brass needs fume extraction at the cutting head, not just room ventilation.
Why does stainless need nitrogen instead of oxygen?
Oxygen assist adds heat and creates a chromium oxide layer on the cut edge. That layer is dark, hard to remove, and can seed pitting corrosion.
Nitrogen is inert. It shields the molten pool and leaves a silver edge that is ready for welding or passivation without a pickling step.
Is laser cutting suitable for carbon fibre sheet?
Usually not. The laser vaporizes the resin matrix but leaves the carbon fibres frayed along the cut edge, and the dust is conductive.
For structural carbon fibre, routing or waterjet gives a cleaner edge and avoids the conductive dust problem. Laser is sometimes used for thin cosmetic panels only.
What tolerance can laser cutting hold?
On thin sheet, a well-maintained fiber laser holds about ±0.1 mm on profile dimensions. On 12 mm plate the kerf tapers and tolerance loosens to roughly ±0.3 mm.
If the drawing calls for ±0.005 mm, laser is not the process. That tolerance belongs to CNC machining, not thermal cutting.
Which plastics should never go on a laser bed?
PVC and any chlorinated plastic top the list. They release hydrogen chloride, which corrodes optics and damages the extraction system.
Polyurethane foam with chlorinated blowing agents and some flame-retardant grades are also risky. Check the material data sheet before cutting.
Does laser cutting harden the cut edge?
On carbon steel, the oxygen-assisted cut leaves a thin hardened layer because the exothermic reaction heats the edge. The HAZ is typically 0.05–0.3 mm deep.
For most brackets and covers this does not matter. For fatigue-loaded parts, a light machining pass removes the hardened layer and restores ductility.
Send the sheet, get a straight answer
Upload your drawing or 3D file. We will confirm the material, the process, and the edge quality you can actually expect, with a quotation and free DFM analysis within 12 hours.
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