... reaching major goals in production


To guarantee quality, a long life and efficiency, the production cycles for making our U-bolts are regulated by strict processes, some originally engineered by Bosio, such as compressed winding forming.
Other processes used at the Santena factories are: hot pressing and forming at a controlled temperature; forming the ends and preparing the average diameter of roll-forming of the thread by extrusion, and finally roll-forming the thread after heat treatment for hardening and tempering, a process that gives the thread added resistance.



  • Preparing average diameter for rolling the thread by extrusion.
    Preparation of the average diameter by extrusion of the ends maintains the continuity of the fibers of the material that otherwise would be interrupted in the turning operation or traditional grinding.
    The continuity of the fiber, especially at the thread end, allows a better distribution of stress, resulting in an increase of endurance strength.
  • Rolling the thread after hardening and tempering.
    Making the thread by rolling after the heat treatment for hardening and tempering further increases its endurance strength and allows it to bear extra load conditions in critical conditions.
  • Compressed-winding forming.
    Compressed winding forming makes the sections at the curve points more resistant, even when the radiuses are very small; this notably improves torque resistance and shear resistance and is a condition that is not present in traditional bending systems because the smaller the curve radius is, the more the section in the curve points is reduced by the stretching of the material. Moreover, the possibility of having very small curve radiuses makes it possible to use U-bolt support bases that are thinner and therefore lighter.


English version
Bosio srl 10026 SANTENA (Torino) Italy - Via Montegrappa, 11 - Tel. 011 949.25.38 - Fax 011 949.26.10