seamless steel pipe/tube, oil casing tube, quality according to the API Spec 5CT, Grade J55, K55, N80, P110 and others... seamless oil casing pipe Seamless pipe used for liquid service,petroleum cracking,oil field,low and medium pressure,and structural purposes and so on.Specifications: ItemMain MaterialExecutive StandardSpecification (MM)SML Steel Tubes for Structural Purposes10#,20#,35#,45#, ...