Circular Hollow Sections
This is a form of hollow section which is particularly effective in circumstances of compression, torsion and bending. It is also probably the most architecturally attractive type of hollow section, and its closed shape, without the sharp corners of squares or rectangles reduces the area that needs to be protected.
It avoids severe contact with the elements because of its lower drag coefficients during exposure to wind or water, and generally protects the structure from corrosion and other wear. Unit costs in the manufacture of hollow sections, whether circular, square or hollow, are higher than for other sections, their applications can be very economical, representing a long term saving as well as excellent structural durability