Cylinder liners are manufactured in gray cast iron in the form of a seamless tube. There are different chemical compositions in the manufacture of gray iron, but the elements most commonly used are: iron, carbon, silica, phosphorous, sulfur, manganese, nickel, chromium and molybdenum. Their hardness ranges from 200 to 260 in the Brinell scale, although this is not a rule. 

The amount of every element varies according to the iron properties required, with a tensile strength of 28 kgf/mm.