... , N80, M65, L80, C90 3.Casing Length: R1,R2, R3 API 5CT Casing 1.Casing Sizes: OD 4-1/2"~20 ... .Casing Length: R1,R2, R3Sell API-5CT Casing, Tubing, Coupling. Our factory manufacture Casing, Tubing: According to API SPEC 5CT Casing . Casing Steel ... ,N80,L80,P11012.415315.3412.19J55,K55,N80,L80,P110 API 4 1/2"Oil casing