Total assembly

mounting and tightening an assembly on-site

Tightening of the screws of an engine

In which situations ?

  • Are you looking for a service provider to assist you with the assembly and tightening of your bolted assemblies ?
  •  Would you like to have the guarantee that your assemblies will be put together correctly and that an even tension will be applied to all of its screws or bolts.
  • Are you looking for a few percent precision in the bolt tension of your assemblies ?

›  Get in touch with TRAXX, the tightening experts ! TRAXX can cover the mounting and tightening of your structure on-site!

A service application example :

Tightening of the structure for the SAFRAN Aircraft Engines flight-testing center, Istres, February 2017


  • 200 Threaded bars
  • Tightened to 700 kN
  • Accuracy : 4%

This 100 t, 18 m high structure is used to test over 1,200 different parameters on new propeller and turbo-reactor engines (Open Rotor and LEAP engine to name but two) under conditions as close to flight as possible.

This test bench must support significant levels of stress: beyond supporting its own weight it must bear the engines suspended from it and stand up to their thrust. In this case we are talking about hundreds of kN. Consequently the pylon will be subjected to simultaneous torsion and traction stresses. Faced with these conditions and specifications the project manager, Latécoère-Services, called on TRAXX for the tightening of the structure.

Over their two weeks intervention, the TRAXX engineers operated on-site, managing the controlled hydraulic tension tightening of the whole of the pylon, this included 200 M35 and M42 threaded bars tightened to over 700 kN.

The assembly and tightening was completed successfully even allowing for a number of additional factors (temperature variations, weather conditions, difficulty of access to some of the threaded bars).

The guarantee that an even tightening tension was applied to the whole of the structure significantly reduced the risk of future incidents. One of the advantages of thinking in tension is that it makes it possible to monitor assemblies over time, controlling the tension in the threaded bars after one year, five years, ten years… a true guarantee for the future.

Do you have a technical question, comment or enquiry concerning tightening systems ?

Write to us !

We will answer your enquiry within half a day.