Qingdao hongbo manufactures and supplies zircornia ceramic liners, HY-chrome liners, hardened steel liners, chrome-plated liners matched performance and durability in most drilling conditions from mountain, desert, plain to offshore drilling. With advanced technology, metallurgical control and rigid inspection, both triplex and duplex liners are available in a wide range of sizes with unmatched performance and durability in the most severe drilling conditions.