High-silicon spheroidal graphite iron

A variant within the spheroidal iron family in which silicon dissolved in the ferritic matrix — at higher concentrations than standard spheroidal iron — simultaneously improves mechanical strength and ductility without requiring heat treatment.
Compared to pearlitic spheroidal irons of equal strength, they offer better machinability and dimensional stability, making them suitable for compressors, planet carriers, and precision components with tight tolerances after machining.