How do you secure a fastening on an aeronautical assembly using pre-bonding ?

Soprima was working one the big names in aeronautics on an aeronautical fastening project. We guided and advised our client from the very beginning of the project by proposing a geometry and sizing that was favourable to the forces that the assembly will have to withstand. 

The technical support role is one of Soprima’s main added values. The contribution of pre-coating here via its bonding function made it possible to secure the fasteners, the structural parts of the aircraft. 


The application of a micro-encapsulated adhesive (a process already qualified by Soprima with aeronautical partners) in the thread of the aeronautical fastener increased the loosening torque by adding an additional adhesive force translated by a breakaway torque.

This additional breakaway torque helped to keep the assembly tensioned and prevented the expansion and vibration phenomena that are particularly challenging in the aeronautical field.

This technique had the advantage of guaranteeing the customer a controlled, precisely dimensioned and repeatable process, without any additional assembly stage (saving time for the customer and eliminating health and safety issues).


Due to the criticality of the use of pre-coating in this aeronautical context, it was necessary to ensure the repeatability and robustness of the pre-coating process.

Our product had to be applied carefully without spilling onto the outer areas. The fill rate was also closely monitored to ensure the complete absence of non-conformities.

Quality monitoring was also reinforced by a more demanding quality control plan and adapted measuring equipment. Sampling and qualification were the result of a joint customer/supplier review of the pre-coating specifications.



Soprima also guarantees the breakaway torque of all its parts using a measurement method defined jointly with the customer.

This test method, which validates the functionality of our product, is mainly based on feedback from over 20 years of experience with our automotive partners.


We carefully study all your technical problems. Our know-how enables us to offer you the most appropriate assembly solution.