IS 3306 specifies pig iron — the primary raw material for iron foundries (to make castings per IS 210) and steel plants (to make steel per IS 2062). Foundry grade pig iron has higher silicon and carbon for castability; basic grade has lower impurities for steelmaking.
Specification for pig iron used as raw material in foundries and steel plants covering grades, chemical composition, and testing requirements.
Key Values
Foundry Grade carbon3.5-4.5%
Foundry Grade silicon1.5-3.5%
Basic Grade carbon3.5-4.5%
Practical Notes
! Foundry grade (high Si) is for casting — silicon promotes graphite formation in grey iron.
! Basic grade (low P, S) is for steelmaking — impurities are removed in the converter/furnace.
! Pig iron quality directly affects casting quality — always verify chemical analysis before melting.