Bi-metal liner's sleeve is made of wear-resistant cast iron, and the surface hardness is HRC60-65. Therefore, liners feature wear resistance, corrosion resistance and high surface finish. Liners are put in from the cylinder cover bore in the front of the cylinder and fixed with liner cage, cylinder cover plug and cylinder cover when installing. 

HNA premium liners combine the strength of a forged steel outer shell with the abrasion and corrosion resistance of a high chromium iron inner sleeve. These liners feature a centrifugally cast high chrome iron sleeve which is machined and heat treated to a minimum uniform bore hardness of 62 RC. Each liner is machined to close tolerances to assure ease of installation and long liner life with the inside diameter of these premium liners honed to a mirror-like finish for smooth even wear during the life of the liner.