Laser cutting is achieved by heating the material using a focused laser beam. As the material melts, it is effectively removed either by gas jet or vaporization, thus creating a cut kerf. There are 3 basic types of laser cutting methods:

In Fusion Cutting, the laser beam is coaxially combined with an inert gas such as nitrogen or argon. The heat produced by the laser beam creates a molten layer that is ejected down through the kerf by pressurized gas from the nozzle. Fusion cutting may be used for cutting mild steels up to 25 mm thick.

Flame cutting, also called reactive cutting, utilizes a laser beam coupled with oxygen gas or air to heat the substrate to its ignition temperature. While the heat produced by the laser beam melts the surface, the gas exothermically reacts with the substrate and creates an additional source of heat to form an oxide layer or slag. As the gas jet ejects the slag from the bottom surface of the substrate, it produces a cut kerf. Flame cutting is often used for cutting alloy steel such as mild steel and thicknesses up to 40 mm at relatively fast processing speeds.