Standard: API 5L GR.B ,ASTM A53 Gr.B ,ASTM A106 Gr.B,20#,DIN, 1) Standard: API 5L GR.B ,ASTM A3 Gr.B ,ASTM A106 Gr.B,202) SPEC:O.D from 21.3mm(1/2") to 508mm(20") SCH40, SCH80,SCH160,DIN3) Thickness: 2.0-70mm4) End: Plain Ends or Threads and Couplings5) Using: For water well,Structural Seamless Steel Pipe