With material of high-quality Proved by used for many years and the scientific experiments, the tubing casing model J55, K55, N80, L80 and P110 our company saled were made of after a multi-channel precision machining processes, together with strict quality control procedures. Standard: API 5CT, API 5B 1) Sizes: OD 4 1/2"~13 3/8"(114.3~339.7mm) 2) Grade: J55, K55, N80, L80, P110 3) Standard: API 5CT, API 5B
