... 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- ... Casing, Tubing, Coupling. Our factory manufacture Casing, Tubing: According to API SPEC 5CT Casing . Casing Steel grade: J55, K55, L80, ... ,L80,P11012.415315.3412.19J55,K55,N80,L80,P110 API 4 1/2"Oil casing