Spheroidal Graphite Cast Iron (S G Iron) or Ductile Iron is considered as one of the most versatile roll materials now a days. It is produced by a small proportion of magnesium added to the melt as nickel-magnesium or alternative alloy, or as pure magnesium. In S G Iron Roll, the free carbon takes the shape of spheroids or nodules, thereby eliminating the notch effect of flake graphite and improving upon the mechanical properties of the cast iron.