Why is the cutting oxygen passed through a preheat flame in oxyfuel cutting?

The cutting oxygen is passed through a preheat flame during oxyfuel cutting primarily to facilitate the cutting process itself. When the preheat flame is applied to the metal, it raises the temperature to a point where the material can readily reach its ignition temperature when the cutting oxygen is introduced. This allows for a more efficient reaction, enabling the cutting oxygen to oxidize the metal and result in a smoother, cleaner cut. By preheating the metal first, the cutting process becomes more controlled, reducing slag formation and improving the overall quality of the cut. The combination of the high-temperature flame and the cutting oxygen ensures that the metal is not only cut cleanly but also helps in achieving a better cut edge, which is crucial in many fabrication processes.