... : +/-10%.StandardRound pipe: GB/8163-2008, GB 8162-2008, ASTM A 106, DIN2391, EN39-2001.Square Steel Pipe: GB/T6728-2002 ... , ASTM A500 Gr A B C, JIS G3466.GradeQ195, Q215, Q235, Q295, Q345, ST37, ST52 ... , Grade A, Grade B.20#, 45#, etc.End FinishPlain/ beveled ends or threaded with ...