The performance targets of Tubing model L80, J55and N80 our company saled were achieved API 5CT standard requirements. With material of high-quality Proved by used for many years and the scientific experiments, the tubing casing model L80, j55 and N80 our company saled were made of after a multi-channel precision machining processes, together with strict quality control procedures. Standard: API 5CT 1) Sizes: OD 4"(101.6mm) 2) Grade: L80, N80 3) Standard: API 5CT, API 5B