... 21.3-610mm 2. Wall Thickness: 3.23-50mm 3. Standard: ASTM A106, ASTM A53, ASTM A179, API5L GR.B, ... X42, X46, 1. Outer Diameter: 21.3-610mm2. Wall Thickness: 3.23-50mm3 ... . Standard: ASTM A106, ASTM A53, ASTM A179, API5L GR.B, X42, ... : API , BS, GB, ASTM,6.Steel grade: GR.A/B, X42, X46, X52, X56, X60, X65, X707.Pipes' ends ...