Premium Chromium Liners(Bi metal liner,Hy-chorme liner )combine the strength of a forged steel out 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 62HRC. Each liner is machined to close tolerance 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 superior performance under tough corrosive and abrasive conditions.