... , K55, N80, M65, L80, C90 3.Casing Length: R1,R2, R3 API 5CT Casing 1.Casing Sizes: OD 4-1/2"~20" 2 ... .Casing Grade: H40, J55, K55, N80, M65, L80, C90 3.Casing Length: R1,R2, R3Sell API-5CT Casing, Tubing, Coupling. Our factory ... manufacture Casing, Tubing: According to API SPEC 5CT Casing . Casing Steel grade: J55, K55, L80 ...