+33 (0)1 40 04 92 30 Lun - Jeu 7h30 - 17h30 / Ven 7h30 - 16h 37, Avenue de Saint-Mandé 75012 PARIS
+33 (0)2 48 50 18 10 Lun - Jeu 8h - 17h / Ven 8h - 16h Rue du Minerai 18570 La Chapelle-Saint-Ursin
ISO 9001 since 1998

SEE THE CASE STUDY – Railway & Transports Industry

The problem

Major rail freight companies rely on their equipment and vehicles to transport heavy loads over long distances, sometimes thousands of kilometers in extreme environments and conditions. Given these very difficult conditions, some of our customers have experienced loosening on critical assemblies. The perfect example is the splice joint bar with a set of different elements, screws, nut against nut, washer, drilling of the screw and pin. There could be several points of failure due to the enormous pressure exerted on these fasteners.

The solution

Having many parts is not a guarantee of safety. In many cases, longer screws will have to be purchased, which increases the cost of expenses. In order to solve their problem, we have delivered our customer an option with a better cost/benefit ratio: our THU self-locking nuts that you can see in the illustration in 1” and 1”1/8.

These full height self-locking nuts, have two slots on the same level, allowing them to withstand high vibrations, heavy loads and extreme temperatures. From the first installation of the THU nuts in December 2017 until February 2019 there was no loosening, even in extreme conditions and temperatures of -14°C.


The benefits for our customers with our THU self-locking nut were immediate:

  • Important increased profits resulting from lower maintenance and fastener shutdowns.
  • Substantial time and labor savings by eliminating daily or monthly tightening of fasteners.
  • Impact wrench compatibility eliminates the need for specialized equipment such as torque wrenches for certain sectors

About us

Founded in 1974, J. Lanfranco & Cie specializes in the manufacture of high-end self-braked nuts and safety fasteners. ESL and ERM have been on the market for more than 40 years, in the most extreme conditions.