... in the east area of China, we were awarded API 5CT and API 5L certificate by American Petroleum Institute, the copy of ... manufacture various kinds of seamless steel pipe: API 5CT casing pipe and oil tubing, API 5L line pipe, ordinary pipe for fluid ... (mm)WT(Ib/ft)GRADETHK(mm)END60.32(2 3/8")4.70H,J,L,P4.83NU , EU5.80C,N,L ... ,P6.45EU7.35C,L8.53EU7.45L,P8.53EU73.02(2 7/8")6.40H,C,N,L,P5.51NU6.50H,C,N ...