Laser Cutting Speed & Cost by Material Thickness

How relative cut speed and cost change with material thickness for fiber laser cutting, across mild steel, stainless steel, and aluminum. Thicker material needs more power and a slower cut, which raises cut time, and the tolerance widens with thickness. The table shows relative tiers and tolerances, not absolute prices or cut speeds, because real values depend on machine power, assist gas, nesting, and the supplier.

How to read this matrix

Each row pairs a material and thickness with a relative cut speed (fast to slow), a relative cost (low to high), and a typical tolerance. The tiers are relative, so a fast, low-cost row takes less cut time and costs less than a slow, high-cost row for comparable work, not a fixed number. Reading down a material column shows the trend: as thickness grows, speed falls, cost rises, and tolerance widens. Reading across a thickness shows how the material changes the result, because mild steel, stainless, and aluminum respond differently to the same beam. Use the table to see the direction and size of the change, then confirm the specific tolerance and time with the shop and the machine that will run the part.

Why speed falls and cost rises with thickness

A fiber laser cuts by melting or vaporizing metal along a path, and the amount of metal to remove grows with thickness. To cut cleanly through thicker stock, the beam needs more power and a slower feed, so the head spends more time per meter of cut and the machine time per part rises. Higher power, slower speed, and greater gas consumption all push the relative cost up the tier as thickness grows. The change is gradual at first and steepens past the mid thicknesses, which is why thin sheet sits at fast and low cost while 10 to 12mm plate moves to slow and high. Nesting many parts on one sheet spreads the cut time and material cost across more parts and softens the per-part rise, but it cannot remove the thickness effect.

Tolerance and edge quality by thickness

Tolerance widens with thickness because thermal dispersion grows with material mass, so the cut edge is less precise on thick plate.

Tolerance by material

Thin mild steel sheet holds about ±0.10mm at 1mm, widening to about ±0.15mm around 3 to 6mm and ±0.25mm at 12mm. Stainless follows a similar path, from about ±0.10 to 0.20mm at 3mm to about ±0.20mm at 10mm. Aluminum runs looser throughout, about ±0.13mm at 3mm widening to ±0.40mm at 10mm, because it reflects the beam and sheds heat fast.

Edge quality and assist gas

Edge quality also changes: thin sheet shows a clean, narrow kerf and a small heat-affected zone, while thick plate shows more taper, a wider HAZ, and possible striation. Assist gas shifts the edge: oxygen cuts thick mild steel faster but leaves an oxide film, while nitrogen gives a clean edge on stainless and aluminum at higher gas cost.

Material differences

The three metals behave differently under the same beam.

Mild steel and stainless

Mild steel absorbs the fiber wavelength well, so it cuts cleanly across a wide thickness range and is the easiest of the three. Stainless cuts similarly but may need slightly higher power because of its alloy content, and it benefits from nitrogen assist for a clean, corrosion-friendly edge.

Aluminum, copper, and brass

Aluminum reflects the beam and conducts heat away quickly, so it needs higher power, nitrogen assist, and looser tolerances, and very thick aluminum tests the limits of the process. Copper and brass reflect the beam so strongly that they need specialized high-power setups or a different process, which is why this table stops at the common structural metals.

When laser is not the right cut

Fiber laser excels on thin to medium sheet, but it is not universal.

Past the thickness limit

Past about 20 to 25mm in steel, edge quality and speed fall and cost climbs, so waterjet (clean, any thickness, no heat) or plasma (thick plate, looser tolerance, lower cost) often fit better. For highly reflective metals like copper and brass, waterjet is the reliable choice.

3D features and the right alternative

For parts that need 3D features, pockets, or holes a flat cutter cannot reach, CNC machining is the route. The thickness and material columns in this table help spot the point at which a switch to another cutting process is worth it.

Limitations

The tiers are relative and illustrative, derived from fiber-laser process behavior, not a price list or a cut-speed chart. Real cut speed, cost, and tolerance depend on laser power, beam quality, assist gas and pressure, lens and nozzle condition, nesting, and the supplier, and a well-tuned high-power machine can extend the clean-cut range. This page compares how speed and cost change with thickness to guide material and process choice; it does not quote prices or per-meter rates. For an actual part, the cut time and cost are set by the supplier against the specific geometry and material, which is outside the scope of this reference.