1) API Spec 5CT 2) J55, K55, L80, N80, P110 3) NUE&EUE API 5CT L80 seamless steel tubingStandard: API 5CTSize: 2 3/8", 2 7/8", 3 1/2", 4 1/2"Steel grade: L80Type: NUE, EUELength: R1, R2 L80 Physical PropertiesY.S. : 552Mpa~655MpaT.S. Min : 655MpaHardness Max : 23HRC