The difference between laser flame cutting and laser-fused cutting is the use of oxygen as a cutting gas. By means of interaction between the oxygen and the heated metal, a chemical reaction is produced to further heat the material. Because of this effect, for the same thickness of structural steel, the cutting rate can be obtained by using this method is higher than that of the fused cutting.
On the other hand, the method is more likely to have a worse quality than a fused cut. In fact it produces a wider slit, apparent roughness, increased heat-affected zone, and poorer edge quality. Laser Flame cutting is not good for machining precision models and sharp corners (there is a danger of burning off the cusp). Pulse-mode lasers can be used to limit thermal effects, and the laser power determines the cutting speed. In the case of a certain laser power, the limiting factor is the supply of oxygen and the heat conduction rate of the material.