Extensive springs (stretchable springs - stretchable springs) - With these springs, the coil rests on the coil so that the spring has as much stiffness as possible and thereby transmits a greater load. They are designed to give a certain force when stretched to a certain length. According to the place of attachment of these springs, the extension springs can have the following lugs:

- Standard lugs (Germany and England)
- Double lugs
- Extended ears
- Swivel lugs
- Inserted lugs
- Special lugs
- Springs with additional thread
- Springs with inserted screw caps

Standard DIN 2097

The dimensions of the material for production are from 0.2mm to 25mm.