Country and language
Choose country:
Choose language:

Success stories


WE‑EF decided to use our HELICOIL® Screwlock thread inserts due to their secure fit and high corrosion resistance.

WE-EF street lights

Lighting up Bielefeld

Corrosion-resistant and high-strength. HELICOIL® Plus Screwlock thread inserts help to protect the environment and save municipal finances. When WE‑EF was commissioned to convert all of the city’s outdoor lights to LEDs, it was the screw connection issue that cast a shadow over the project.

Initial situation

Extreme material requirements

WE‑EF specialises in outdoor lighting

Its LED lamps are exposed to varying climate conditions, high traffic volumes and, in some cases, extreme weather. As a result, protection against corrosion and vibration had to be guaranteed for long-term market success. To meet these demanding requirements, WE‑EF used 5CE technology: unmixed, recycled aluminium alloys with a low copper content.

The only remaining weakness was the conventional screw joint. These were unable to withstand major shocks during testing.


HELICOIL® Plus Screwlock thread inserts

WE‑EF uses our HELICOIL® Plus Screwlock thread inserts. 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 DIN EN ISO 2320. This, together with high corrosion resistance, ensures the HELICOIL® thread inserts do not come loose. As a result, they contribute to the durability of WE‑EF street lighting. This is one of many benefits currently enjoyed by the city of Bielefeld.

HELICOIL® Plus Screwlock – thread insert for metals
HELICOIL® Plus Screwlock thread insert for metals
HELICOIL® Plus Screwlock Thread inserts for metals with screwlocking effect


Lower energy consumption

14,800 luminaires replaced, 42 % lower CO₂ emissions, and a reduction in power consumption of around 5 million kWh per year – the figures are remarkable. Thanks to reduced light diffusion, the new LED luminaires are also enhancing the daily lives of the citizens of Bielefeld. With WE‑EF's OLC® (One LED Concept) lens technology, the light is focused on the surface to be illuminated. We are delighted that our HELICOIL® Plus Screwlock thread inserts can make such a long-term contribution to the environment, the city’s finances and, of course, our customer WE‑EF.

Customer benefits

  • Anti-loss
  • Increased value
  • Quality improvement
Bielefeld, Rabenecksheide, lighting before and after conversion to WE-EF VFL540 LED street lights
Lighting before (small image top left) and after conversion to WE-EF VFL540 LED street lights

we will be happy to help.

Do you have any questions or a current project?

Just let us know and we’ll get in touch

Contact us