Oxy-fuel cutting is the oldest and most commonly used steel cutting method. It is used for cutting materials 3-300 mm thick. A burning gas jet or flame (acetylene or propane) is used to heat the steel to its ignition temperature (approx. 900°C). Oxygen is mixed into the fuel flame to enhance the melting and burning process. The gas jet oxidizes and blows away the liquid steel and oxidation products, producing a hole. The flame motion at a proper speed forms a continuous gap between the plate parts to be separated.