Air When heated up to 30*000 F Undergoes ionic changes & reaches the fourth state of matter, called plasma. Instead for expensive Argon or Nitrogen onl;y compressesd air is used. Hence called Air Plasma. APPLICATION Air Plasma can be used to cut following matels: Mild steel Stainless steel carbon and Alloy steel Aluminium and its alloys Copper Casting Bronze Brass Maganses steel and special alloys etc.