What is a gas spring?
Gas springs, also known as gas shock absorbers, gas pistons, hydraulic pistons, gas struts, or hydraulic dampers, are devices made up of a sealed steel cylinder that contains nitrogen (and in some cases oil) under pressure, inside which a piston attached to a rod moves through a sealed guide system. Their main function is to balance and support the weight of various elements, allowing for smooth opening and controlled, gentle closing of doors, lids, covers, panels, and other applications. Thanks to their support and damping effect, gas springs ensure safe, stable, and easy movements for the user.
Within this technology, LIFT is a commercial name used to refer to non-locking gas pressure springs, meaning they do not allow fixation in intermediate positions and operate continuously throughout their entire stroke. These gas pistons are specifically designed to optimally balance weight through their force-support effect and are characterized by their advanced damping properties, which ensure particularly smooth, safe, and controlled movements for the user.
We know that, on many occasions, questions can arise when it comes to replacing a gas spring that, due to wear, a leak, or simply the end of its service life, needs to be replaced and we don’t know how to find the right alternative.
Next, we explain in a simple way what information is needed to identify the correct gas spring, understand how gas springs work, and make their search as easy as possible.
Information needed to identify your gas spring
1. Total extended length
It is essential to measure the gas spring fully extended, as this is the only way to determine its optimal stroke and choose the appropriate gas spring. To obtain this measurement, you should measure from the center of the head or end fitting on one side to the center of the head or end fitting on the other side. This measurement is key to ensuring that the new spring fits and functions correctly.
2. Force or compressed gas pressure (N)
It is also necessary to know the force of the spring, gas strut, or gas piston, indicated in Newtons (N). This value represents the capacity and pushing force of the gas spring through the internal gas pressure. In our case, we charge the gas to measure at the time of assembly. We do not work with springs preloaded by third parties nor store precharged units for long periods, as this can cause deterioration and possible leaks, reducing the actual force of the spring over time. In this way, we ensure that the product delivers the exact specified force.
2.1 Weight and centre of gravity: the figure you need before working out the force
How a gas spring works comes down to three ideas: weight, centre of gravity and moment. Understanding how gas springs work is what lets you choose the right gas spring for each application, whether that is doors, lids, hatches or industrial equipment.
The weight is the load the spring has to help move, while the centre of gravity is the point where that load is concentrated. The distance between that point and the hinge, together with the weight, determines the force (N) needed to open and close the application. Depending on the design, the size and the position of the element, this calculation can vary.
That effort is known as the moment, or torque, and it represents the turning effect the weight produces on the hinge axis. To balance it, the gas spring works through the internal pressure of the gas held in a precisely sealed cylinder, generating the force needed for a controlled, safe movement with as little friction as possible.
Weight, centre of gravity and moment are therefore key factors in choosing the right gas spring, setting up its mounting correctly and guaranteeing optimal performance. Both compression gas springs and traction gas springs work on this same principle, although each type is designed for different needs and working conditions.
Moment balance formula
For the door or lid to stay in place or move smoothly, the principle of moment balance applies:
P × A = F × K
- P: Weight of the lid or load.
- A: Distance from the centre of gravity to the hinge.
- F: Nominal force of the gas spring (in Newtons).
- K: Effective lever arm of the gas spring.
Why does the spring need more force than the lid weighs?
Since gas springs are usually mounted very close to the hinge, their lever arm (K) is much smaller than the distance of the lid itself (A). For this reason, the nominal force (F) of the spring in Newtons has to be considerably greater than the static weight to guarantee smooth, assisted lifting and opening.
3. Type and dimensions of the end fittings
Finally, we need to know the characteristics of the end fittings of your gas damper, which can vary depending on the application. It is important to specify:
- Diameter of the end fitting hole
- Thickness (in case it is an eyelet)
- Material
With this information, we can offer the most suitable and personalized solution according to each customer's needs.
Tailor-made solutions for your specific needs
In our catalog, we offer a wide range of universal gas springs, with low, medium, or high resistance, available in both steel and stainless steel, covering most common applications. However, if you need to choose a gas spring with very specific dimensions and that meet particular requirements, a certain force, or special characteristics—whether for a new project or because you need different performance—we manufacture the spring entirely to measure, as our gas springs are tailored to the needs of each of our customers.
We have our own manufacturing facilities, without intermediaries, our own stock, and the technical capability to produce from scratch the exact spring you need.
Important note: We do not require a minimum order. We manufacture and ship from a single unit up to large volumes (with the corresponding discounts), serving both individual and industrial customers. That’s why our solutions range from gas springs for door lifting, gas springs for storage beds, foldable beds, campers, kitchen furniture, pneumatic lifts, toy boxes, gas spring products for the automotive industry, to industrial gas springs for industrial applications.
Our gas springs in action
Gas Springs Trunk
Gas Springs Kitchen Cabinet
Gas Springs Industry
Gas Springs for Canape
If you want to learn more about their applications, you can visit the article Applications on our blog.
We make direct shipments from Valencia to anywhere in the country, quickly, with delivery times of 24–48 hours once the order is prepared, being a reference for gas springs in Spain thanks to our personalized service and fast delivery times.
We invite you to use our advanced and specialized tool for calculating your gas springs: by entering just a few details, it will recommend exactly the right gas spring for you.
Calculate my springHave questions? Contact us
If you have any questions, please contact our customer service team. We will be happy to help you find and select the spring: