Gas springs Liftline

The gas spring, also called gas strut, gas pressure springs, gas dampers or gas pressure dampers, will solve your individual requirements for opening, closing, tilting and damping flaps, tables, seats or loungers thanks to our decades of experience. They take care of the controlled movement sequence and offer the following advantages:

  • Simple installation
  • Compact design
  • Integrated damping
  • Definable spring characteristic and extension speed

Gas spring standard product range

The SUSPA standard product range of gas springs includes five different basic types 16-12, 16-1, 16-2, 16-4 and 16-6.

TypeØ Tube (mm)Ø Piston rod (mm)Stroke max. (mm)Extension force F1 (N)
16-1212415040 - 180
16-115615050 - 420
16-218.5825080 - 750
16-3228495100 - 1,200
16-42210495100 - 1,200
16-62814500200 - 2,490


What is a gas spring? How is a gas spring built, how does it work and how do you find the right gas spring for your purpose? We will briefly present the most important functions here.

  • What is a gas spring?

    Gas springs are hydropneumatic adjustment elements.

  • Structure of a gas spring

    Gas springs consist of a pressure tube and a piston rod with a piston unit. Connection parts to the pressure tube and the piston rod allow for the suitable connection for your application. The core of the SUSPA gas spring is the special sealing and guiding system. This ensures the hermetic sealing of the interior with low friction, even under extreme environmental conditions.

  • Extension force of the gas spring

    The gas spring is filled with non-toxic nitrogen under high pressure. This produces a charging pressure that acts on the cross-sectional area of the piston rod. This generates the extension force. If the extension force of the gas spring is higher than the force of the counterweight, the piston rod extends. If the extension force is lower, then the piston rod retracts. The flow cross-section in the damping system determines how quickly the extension occurs. In addition to nitrogen, there is a defined amount of oil in the interior for lubrication and end position damping. The suspension comfort of a gas strut can be determined as needed and for the respective task.

  • Spring characteristic of the gas spring
    Spring characteristic of the gas spring

    As can be seen from the graphic, the spring characteristic represents the force progression of the gas strut over the stroke, from the extended to the compressed state and back. In the process, the spring characteristic value represents the force ratio F2/F1. When designing a gas strut, the force F1 is the most important criterion in addition to the dimensions. The force F1 is measured 5 mm before the end of the extension movement, thus defining the value of the spring force. The force FR resulting from the friction is created between the force lines in the compressed and extension direction. The extension speed is divided into two types of damping: With the standard gas strut, the extension speed is controlled via a pneumatic and hydraulic range. When installing the gas spring with piston rod facing down, the piston first moves through the gas-filled part (pneumatic area), then through the oil-filled part of the pressure tube (hydraulic area). The piston rod is braked by the oil.

    If desired, the damping can also occur dynamically. For this purpose, a longitudinal groove is provided in the pipe, which allows for a positionally-independent damping of the gas spring.


    Gas springs with hydraulic damping can be designed as special versions according to the following principles:

    • extension-damped gas strut
    • compressed-damped gas strut
    • compressed and extension-damped gas spring
    • Gas spring without damping



  • Design and Development

    The SUSPA gas spring Liftline is individually designed depending on the installation situation. For us, the focus is on the function of the entire application as well as the individual coordination of the kinematics and the spring characteristics in accordance with the requirements profile. Gas springs are tested in our technical department on systems, test equipment and trial facilities:

    • Linear test benches
    • Folding test benches 
    • Climate test chamber 
    • Hydropulser
    • Tailgate simulation 
    • Speed / acceleration measurement 
    • Laboratory for metallurgy and corrosion tests 
  • Selecting the gas spring

    The following conditions are generally to be observed when selecting the suitable SUSPA gas spring: 

    • The ratio of the diameter of the piston rod to the tube determines the force progression of the spring characteristic. Flat characteristic curves require a small piston rod diameter and a large pipe cross-section.
    • A longer stroke means smaller required forces of the gas strut and in this respect smaller reaction forces at the pivotal points. 
    • A larger piston rod diameter should be chosen for extremely long strokes paired with high extension forces. This solution offers a higher level of safety against the gas strut buckling. Correspondingly, the effect of transverse forces acting on the gas spring should be avoided in general. 

    SUSPA gas springs correspond to the highest requirements in a variety of application areas due to their basic design and their reliability. However, it is up to the user to check the suitability for the respective application case. We are happy to help you select the appropriate SUSPA gas spring and install it properly. 

Sector finder

SUSPA gas struts offer comfort and safety in many applications.