The presence of free graphite flakes in the working layer distinguishes indefinite chill cast iron rolls from clear chill cast iron rolls. Free graphite improves the elastic properties of the material, reduces the effect of specific rolling loads, and favours heat exchange by increasing the resistance to thermal fatigue. The structure is also made up of cementite which increases wear resistance, in a pearlitic or bainitic/martensitic matrix. Rolls may be supplied as monobloc or as compound. When high hardness is required in the working layer in combination with highly resistant core metal, the use of compound (double poured) rolls is recommended.
Indefinite chill cast iron rolls are used above all as pre-finishing and finishing rolls for rods, flats, light and medium sections.