Cast Iron

Cast iron is a ferrous alloy primarily composed of iron, carbon, and silicon. By definition, cast iron contains higher carbon content than steel, typically ranging from 2.5–4.0%, depending on the size and grade of the casting. Silicon is intentionally added as an inoculating agent, promoting the formation of graphite as excess carbon precipitates from the molten iron.

This graphite structure gives cast iron many of its defining characteristics, including excellent machinability, wear resistance, thermal stability, and vibration-damping properties—making it a preferred material for a wide range of industrial applications.

Cast iron is not a single material, but rather a classification that encompasses a broad range of material grades, each engineered for specific performance requirements. The two primary categories of cast iron are:

• Gray Iron – Known for its graphite flake structure, superior machinability, and exceptional vibration damping

• Ductile Iron – Characterized by nodular graphite, offering higher strength, ductility, and impact resistance

Together, these material families allow engineers and manufacturers to select cast iron grades tailored to strength, durability, machinability, and performance needs across diverse applications.