It increases low and high temperature strength in Steels and Cast Irons. Improves corrosion resistance of Stainless Steels. It is a strong hardenability agent. Used also as a strong carbide former and moly steels can exhibit a secondary hardening peak.

This fact, plus molybdenum's ability to strengthen ferrite even at elevated temperatures, has led the application most wider in the manufacturing of heat-resisting steels. Ferro molybdenum is used mainly in production of alloys steel, such as structual steel, spring steel, bearing steel, tool steel, antiacid stainless steel, heat-resistant steel and magnetic steel etc.