The world is full of all kinds of structures, some of which are more durable than others. The tube is one of the simplest and most durable structures in the world. A tube is a strong structure, but at the same time it is also very light. In addition, tubes do not take up a lot of raw material to produce, which saves a lot of money. This is why steel tubes are used to build all kinds of things, from furniture to traffic signs.

Tube structures can be used to build furniture (on the right) or traffic sings (on the left).

Many kinds of tall structures, such as floodlights and light posts, are made from steel tubes. Steel tubes are very durable, but they are also light to transport and handle. 


Steel tubes can be used to build durable, tall structures.

The bones of the human limbs are also hollow. Hollow bones are durable, but they are also lightweight. The bones of other animals can also be hollow. For example, most of the bones in the body of a bird are hollow. This makes it easier for the bird to fly.


Tubes are durable but light structures. They can be found in electric posts (on the left) or even in bones (on the right).