Standard:JIS, GB, DIN, ASTM Grade:10#-,45#, A53-A369, ST35 ... carbon steel pipe 1)Standard: ASTM B 16.9 /16.11 B 16.28 JIS B 2311/2220 DIN2617/2616/26152)Specification:Thickness ... steel pipe StandardAPI 5CT, 5L; ASTM, BS, JIS, DINSteel GradeAPI 5L Grade B/ASTM A106B, BS 1387O.D.21.3-610mmW ... advanced paymentQualificationIndependent import and export qualifications A106/A53 GR.B seamless carbon steel pipe