Success stories


Exterior lighting is exposed to wind and weather. Because of their secure fit and maximum corrosion resistance, WE-EF chose our HELICOIL® Screwlock thread inserts.


Bielefeld illuminated

Corrosion-resistant and high-strength. HELICOIL® Plus Screwlock thread inserts help to conserve the environment and municipal finances.

Bielefeld has to save money. And energy. Therefore, WE-EF was commissioned to convert all of the
outdoor luminaires to LED lights. Only the screw locking issue cast a cloud over the project. With HELICOIL® Plus Screwlock thread inserts, the problem could be solved.

Initial situation


Extreme material requirements

WE-EF specialises in exterior lighting.
Right across the world. Varying climate conditions, high traffic volumes and, in some cases, extreme weather make high demands on the LED lamps’ capacity. Reliable protection against corrosion and vibration has to be guaranteed for long-term market success. To meet these high demands, WE-EF used 5CE technology: unmixed, recycled aluminium alloys with a low copper content.
The only remaining weakness: The conventional screw joints. They were unable to withstand major shocks during testing.

Customer profile


Bispingen / Germany




HELICOIL® Plus Screwlock thread inserts

WE-EF uses our HELICOIL® Plus Screwlock thread insert. Its screw-clamping section effectively prevents the screw from working loose due to vibrations. One or more polygonal threads clamp the flanks of the installed screw. The elastically resilient frictional locking results in prevailing torques similar to the specifications of ISO 2320. This, together with the high corrosion resistance, means that HELICOIL® thread inserts do not come loose. They thus contribute to the durability of WE-EF street lighting. And the city of Bielefeld benefits too.



Lower energy consumption

14,800 replaced luminaires, 42% lower CO2 emissions and a reduction in consumption of around 5 million kWh per year – these figures are remarkable. Thanks to the lower light diffusion of the new LED luminaires, the citizens of Bielefeld also benefit in everyday life. By means of WE-EF's OLC® (One LED Concept) lens technology, the light is focused specifically onto the surface to be illuminated. We are delighted to contribute to their long-term success with our HELICOIL® Plus Screwlock thread inserts. For the environment, municipal finances and, of course, our customer WE-EF.

Customer benefits

  • Anti-loss
  • Increased value
  • Quality improvement


Find out more: related downloads.

If you would like to know more, simply download the relevant brochures.

Title Language Version File Download
Success story
WE-EF and Böllhoff light up Bielefeld
English 0318/15.02 333 kB / PDF
English 0318/15.02 333 kb / PDF
Metric thread inserts for metals
English 0100/16.02 2969 kB / PDF
English 0100/16.02 2969 kb / PDF

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