CamaSteel sells different forms of steel tubes and pipes that are commonly used today. Steel tubes and pipes, however, do not have the same applications and vary in sizing. They both have a hollow cylindrical shape but that is where the similarities end. For example, pipe diameters are calculated using the inside diameter whereas tubes are calculated using the outside diameter. Steel pipes usually cover larger applications than steel tubes do. Another distinguishing factor is the shape of the inside where steel pipes only have round sections and tubes can be round, square, and rectangular. Steel pipes are also typically used for transporting or dispensing liquids and gases, so it is important to know the capacity and tolerance of the pipe. Steel tubes on the other hand are used in manufacturing and for structural purposes.