-    Square tube (1)
     -    Rectangular tube (1)
     -    Cap tube (1)
     -    Oval steel tube (1)
     -    Triangular steel pipe (2)
     -    Inner hexagonal seamless pipe (1)
     -    Hexagonal pipe (1)
     -    Inner circle outside the hexagonal seamless pipe (1)
     -    Hexagonal seamless tube within the cylindrical (3)
     -    Within the straight teeth seamless pipe (1)
     -    Outside the straight teeth seamless pipe (1)
     -    Other Special Pipes (1)