Grey cast iron is a type of cast iron with lamellar graphite. It is an alloy of iron and carbon. The carbon content in the alloy is between 3.0 and 3.7 %, its other components being silicon (1.5 to 2.5 %), manganese (0.5 to 1.4 %), and sulphur (up to 0.12 %). Carbon is excreted in iron in the form of graphite lamellas or sheets. The fracture surface of such iron is grey in colour, after which the alloy was named.
The properties of grey cast iron mainly depend on the size and shape of the excreted graphite sheets. The larger the graphite sheets, the larger the cracks in cast iron and the lower its strength.
The main mechanical properties of grey cast iron are its tensile strength and hardness. Both are regulated by the EN-1561 standard, which classifies individual types of cast iron by quality. Livar manufactures grey cast iron in the range from EN-GJL-150 to EN-GJL-350.