Malleable iron, like ductile iron, possesses considerable ductility and toughness because of its combination of nodular graphite and low-carbon metallic matrix. There are two basic types of malleable iron: blackheart and whiteheart. This article focuses on the blackheart malleable iron and discusses the chemical composition of malleable iron. A summary of mechanical properties and specifications of malleable iron castings is presented in a table. The article also reviews the mechanical properties of ferritic malleable iron and pearlitic and martensitic-pearlitic malleable irons.