Ferro Silicon Magnesium Alloys are used to produce all types of ductile cast iron. It is added to the molten iron for producing a structure containing graphite in nodular or spheroidal form. This form minimizes the embrittlement effect of graphite on the metal matrix with the result of producing cast iron with better machinability, toughness, and tensile properties. Ferro Silicon Magnesium consists mainly of magnesium silicides combined with the silicides of iron, calcium and rare earth metals.