Steel Tube Standard: GB/T3639,8162,3087,ASTM A106,A192,BS3059,3601,3602,6323, DIN1629,1630, JIS G3454 Grade:1010, ... structure steel cold draw and extruded tube seamless by standard GB/T3639,8162,3087,ASTM A106,A192, BS3059,3601,3602,6323, DIN1629,1630 ... , JIS G34541.Standard:GB/T3639,8162,3087,ASTM A106,A192,BS3059,3601,3602,6323,DIN1629,1630,JIS G34542.Grade:By ...