It is considered the noblest material due to its valuable qualities. Compared to other materials, titanium has a low density (around 4.5 kg / cm3 - with small variations depending on the type of alloy) which is equal to 58% of the density of stainless steel. The melting point is very high (around 1,700 ° C) while the modulus of elasticity and the coefficient of linear thermal expansion are very low. Among the qualities of titanium there is also the almost total insensitivity to corrosion, a notable advantage for the construction of bicycles. On the other hand, titanium is one of the most difficult materials to use. Processing is complicated and requires special (and expensive) machinery. Titanium tubes can be made by drawing or by winding a titanium plate subsequently welded along the length. Due to its characteristics, titanium must be welded in a controlled atmosphere, this is because when it is brought to the melting point, titanium tends to absorb the gases present in the air, losing its mechanical qualities.

Due to the complicated manufacturing process, titanium is ten times more expensive than conventional steel. The creation of a titanium frame is very particular and requires specific equipment. In fact, this material is very difficult to work with machine tools, due to its hardness, and requires high torques and speeds. Furthermore, the grooving and preparation of the pipes must be done by hand, since working it with mechanical grinding wheels or pipe cutters would compromise its characteristics. Its high weldability (especially grade 9) is subject to the influence of oxygen, nitrogen and hydrogen present in the air.

During welding, titanium heats up and becomes very reactive with atmospheric elements, which bind and oxidize the weld and irretrievably weaken the material. For this it is necessary to weld it in a protective atmosphere of argon, an inert gas that isolates the material and prevents oxygen from binding (a bit like it happens in TIG welding, of which we have already spoken). Welding in a protective atmosphere takes place by inserting the pipes to be joined, the pliers with the tungsten electrode and the filler rods in a glass bell in which argon is pumped to saturate it and expel oxygen, while the welder, from the outside , make the joint. You can understand for yourself that the costs for this type of processing are really high. There is a system to overcome this problem and be able to weld the Ti also outside the bell and it is a procedure used in the aeronautical sector for welding the titanium rods which are the structural basis of the aircraft. Using the classic TIG welding system, however, an increased Argon cone (called gas lens) is used, therefore with a larger volume, capable of covering the entire weld and thus protecting it from the dangers of oxygen.