1.API 5CT N80 oil casing pipe 2.OD:6-760mm WT:1-30mm 3.Grade:J55,K55,L80, ... · API 5CT N80 oil casing pipe 1. Size:OD:6-760mm WT:1-30mm2. Grades:N80,J55,K55,L80,P110 ... It is inserted into a well bore and cemented in place to protect both subsurface formations and the wellbore from collapsing and ... and natural gas from a well.Size(mm)O.D.:6-760mm W.T.:1-30mmGrade and Chemical Composition (%) Gradechemical ...