Oxy acetylene cutting is known by many names, such as oxy cutting, oxy-fuel cutting or flame cutting. It is a process where fuel gases and pure oxygen are used for cutting.
Flame cutting uses pre-heating. First, the flame heats up a spot on the metal. Then a high-pressure stream of pure oxygen is directed towards this spot. Hitting the heated spot ignites the oxygen which, in turn, cuts the metal. The cutting flame temperatures rise up to 3500°C.
The cutting torch usually has a central hole and some more placed around it. The holes around the central jet are for guiding oxygen and acetylene onto the workpiece to preheat it. The central jet is for oxygen only – it provides the final cutting gas.
Flame cutting is excellent for cutting steel. The reason why it only works well with steel is related to the chemical reactions taking place. When the metal melts, it combines with oxide to form iron oxide. This makes the cut possible.
Therefore, it is a good option when working with ferrous metals but is pretty much unusable with aluminium or even stainless steel. Aluminium oxide has a higher melting temperature than iron oxide. This is why it is not used there. Stainless steel, on the other hand, is actually used for those non-oxidising qualities, making these metals also unsuitable.
For these reasons, it is necessary to find an alternative when thick plates from materials other than carbon steel need cutting. One possibility is waterjet cutting.