Fabrication of a tubular frame is not a simple process. It becomes challenging if two tubes are meeting each other at 90°. It becomes more challenging if two tubes are not meeting each other at an angle of 90°. This challenge becomes even more difficult if more tubes meet at the same point and/or the cross-sections of the meeting tubes are different. If one uses the conventional fabrication method, it involves multiple steps and a variety of machines. 

Structures and frames made of metal tubes have long since become widespread in all industrial sectors. Their presence and complexity have gone hand in hand with the availability of tools and technologies capable of designing and implementing them in a way that makes them functional but also, and above all, cost-effective.

Light and robust, of high-quality appearance and in a wide range of shapes and sizes, tubes have inspired generations of engineers in the most diverse fields. Furniture, mechanics, automotive, hydraulics, just to name a few, without forgetting the major construction sector, that has experienced the most significant growth in recent times.  We see tubular structures in the constructions: supporting the roof that one can see in airports, railway stations, etc. Similar tubular structures are also used in the industrial sector including machine frames, various structures within agricultural equipment and cranes, etc.  

You find these examples also in modern indoor and outdoor furniture starting from the many types of chairs, school bench structures and table legs.