... 3.Standard:ASTM A53,BS1387,API 5L,GB/T3091 4.Own two factory 5.MOQ:10MT COMMODITYASTM A53 BS 1139 Qualified 3/4 ... Q195-Q345,A36, A53,ST35, ST37STANDARDASTM A53, ASTM A500, BS1387,BS 1139PAYMENT T/T. L/CTRADE ... TERMS FOB/CFR/CIF/EXWMIN QUANTITY20MTPLACE OF ORIGINTianjin City, China END TREATMENT Plain/Beveled/Threaded ... with black painting. The Tolerance of Outer Diameter and Wall Thickness(GB/T)