What is laser cutting?

The process is thermal: the beam melts or burns the material, and the assist gas helps decide which. With nitrogen it is fusion cutting, giving a bright, oxide-free edge on stainless steel and aluminium; with oxygen it is laser flame cutting, faster in mild steel but leaving an oxide layer on the edge. Compressed air sits in between for thinner sheet. No tooling is needed per shape. Input is usually a DXF or a flat pattern from the 3D model; parts are nested on the sheet and often held by micro-joints until they are broken out.

What decides cut quality in laser cutting?

Cutting speed and quality depend on material, thickness, laser power and beam quality, assist gas and pressure, focus position and nozzle. Every internal profile starts with a pierce, which takes noticeable time in thick plate. In small radii and sharp corners the machine slows down. The cut has a width, the kerf, which the program compensates for, and the edge can show a slight taper, striations and dross on the underside. A heat-affected zone runs along the cut, which can harden the edge of hardenable steel; that matters for tapping or later machining. Holes that are small relative to the sheet thickness lose accuracy and are then often drilled.

What does the standard say about laser cutting?

For thermally cut edges, including laser, plasma and oxyfuel, ISO 9013 is often cited. It classifies cut quality by the perpendicularity or angularity tolerance of the cut face and the mean profile height of the cut surface, and gives limit deviations for the dimensions of cut parts. A requirement is only unambiguous with the class or range stated; a drawing that just says ‘laser cut’ leaves the quality open and is worth querying.

How does laser cutting work in practice?

Machine time follows total cut length, thickness, the number of pierces and the rapid moves. Material cost per piece depends on how well parts nest and whether you charge the remnant; a one-off on a whole sheet is relatively expensive. Whether the edge still needs deburring, rounding or machining follows from its function: an oxide layer can hinder paint adhesion or welding, and for a fit a cut edge is usually not accurate enough.

What is laser cutting often confused with?

Laser cutting is not laser marking: cutting goes through the material, marking only changes the surface. Plasma cutting is thermal too, but leaves a wider kerf and a rougher, more tapered edge, and is mainly of interest in thick plate. Waterjet cutting works without heat and so leaves no heat-affected zone.