Tension springs

Tensions springs are usually tightly wound but can also be supplied with pitch, with or without initial force. A wide range of hooks and eyes is available. The most important parameters in the specification of tension springs are:

  • wire
  • exterior diameter
  • free length
  • initial force (if applicable)
  • type of material


We work in most types of spring material, of which the most common are:

  • EN 10270-1- SM (SS 1774-04) Spring steel
  • EN 10270-3-1.4310 (SS 2331-06) Stainless steel

We also handle any surface treatment required. Our modern machines allow us to manufacture tension springs with wire diameters of 0.20–15 mm. We supply batch sizes from a single spring to limitless quantity.


Our tension springs are used in a wide range of products, including:

Locks, contacts, note handling equipment, photocopiers and grinders.


When ordering tension springs:

State all measurements in mm and forces in N.
Unless stated otherwise, the material used will be spring steel.
Please include requests for special material, surface treatment and any special conditions. If required, we can provide assistance with calculations and dimensioning

Dt = Wire diameter

Dy = External diameter

L0 = Free length, measured inside on hook/eye

nv = Number of active coils

H1/H2 = Internal height of hook/eye in mm (normally 0.75 x Di)

Ö = Hook curve in mm

C = Spring constant in N/mm

F0 = Initial force in Newtons

F1 = Spring power at length L1

L1 = Loaded length