Chemistry of Oxygen Cutting:

The procedure of oxygen cutting is depend on the ability of high purity oxygen to combine quickly with iron when it is heated to its ignition or kindling temperature, above 870°C. The iron is quickly oxidised by the high-purity oxygen and heat is liberated by various reactions. The balanced chemical equations for these reactions are as following:

Fe + O = FeO + heat (267 kJ), first reaction

3Fe + 2O₂ = Fe₃O₄ + heat (1120 kJ) second reaction

 2Fe + 1.5O₂ = Fe₂O₃ + heat (825 kJ), third reaction