The laser beam is focused for cutting. All its power is bundled onto one point, usually with a diameter of less that half a millimeter. Where the focused beam strikes the workpiece, the metal immediately begins to melt. It even partly burns or evaporates.

After a short time, the laser beam penetrates the material completely. The real cutting begins after this penetration. The laser beam moves along the contour of the part and melts the material as it advances. Molten metal and slag are blown away in a downward direction. This creates a narrow cutting gap that is barely wider than the focused beam itself.

In cutting, the laser beam processes the sheet, contour for contour.

Notches in the part are always cut before the outer contour. The processing of each contour begins with piercing. The point where the sheet is pierced generally lies a little removed from the contour, in the scrap skeleton. In thicker sheets, material is thrown upward when the sheet is pierced, and the point of penetration is wider than the later kerf.

After penetration, the laser beam first cuts until it reaches the contour and only then begins to cut the actual contour. To blow metal melt and slag out of the kerf, a cutting gas is blown into the slit under pressure. The type and pressure of the gas have a great influence on the cutting process and the cutting result.