Laser cutting (sheet metal): how it works, costs and design rules

A focused laser beam cuts flat shapes from sheet or plate. It is the cheapest way to make flat parts with holes and contours in steel, stainless and aluminium, and it is the first step for most bent sheet metal parts.

Typical tolerance

±0.1–0.2 mm

Quantities

1 to 10,000+

Lead time

2–10 working days

Materials

Steel and stainless up to about 25 mm, aluminium up to about 15 mm

How it works

A fibre or CO2 laser melts the material along a programmed path and assist gas blows it out of the cut. Parts are nested on a full sheet to use as much material as possible.

Benefits

• No tooling, fast and cheap per part.
• Complex 2D shapes cost little more than simple ones.
• Good edge quality on thin material.

Limitations

• 2D only (bending is a separate step).
• Slight taper and heat-affected edges on thick plate.
• Holes smaller than the material thickness are unreliable.

What drives the cost

• Total cut length and the number of pierce points.
• Material type and thickness.
• How well the part nests on a standard sheet.

Design rules

• Make holes at least as large as the sheet thickness.
• Keep features at least 1× thickness from edges and from each other.
• Use standard sheet thicknesses.
• Add small radii to inside corners to reduce stress and burning.

Preparing your STEP file

• Send a flat DXF at 1:1 in millimetres, plus the STEP for bent parts.
• Remove text and tiny details the laser cannot cut, or mark them as engraving.
• State the material grade and thickness on the drawing or in the file name.

See also the full STEP export checklist and the comparison of all processes.