How do I tell the difference between a torsion spring and an extension spring?

The torsion spring
— The torsion spring is fitted ONLY on sectional doors, and is installed horizontally. Torsion springs can be "at the front" = next to the lintel; they can also be "at the back", placed at the other end of the rails.

The extension spring
— It's most often installed vertically but can sometimes be positioned horizontally, on either side, along the sides of the door, along the guide rails; they stretch as the door closes and relax as it opens.
Extension springs can be found on their own, but also in clusters of several springs. To identify a spring in a cluster, look for the reference engraved on the hook.

Still not sure?
Send us:

• An overall photo of your door closed.
• The ends of the springs.
• The door's identification plate

Updated on: 08/07/2026