Spheroidal Graphite Iron Rolls (S G 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.

In these rolls the graphite is in the from of spheroids produced by suitable inoculation. Most nodular iron rolls are chill cast resulting with a hard working layer and softer nects. The alloy content is accurately controlled to give fine and well distributed graphite nodules and refined carbide in generally pearlitic or beinitic / martenstic matrix. The Higher alloy contaent Cr-Ni-Mo makes the rolls more tougher & wear resistant.