Gas springs – often referred to as gas struts – are widely used across engineering, manufacturing, automotive, and industrial sectors. Compact and self-contained, these precision-engineered components enable controlled lifting, lowering, and positioning of panels, lids, machinery, and equipment. Their smooth motion, reliable counterbalancing, and predictable performance make them essential in everything from everyday products to advanced industrial systems.
With decades of industry-leading expertise, Lesjöfors supplies high-performance gas spring solutions for demanding environments. Our products support safe movement in salt-rich marine conditions – such as boat hatches and engine covers – and deliver dependable, long-term performance in hygiene-critical medical settings, including diagnostic units and laboratory enclosures.
Understanding what a gas spring is, how it works, and where it adds value is key to selecting the right solution. In this article, we explain the fundamentals, from the difference between springs and struts to the core gas-pressure mechanism, the main types available, and the industries where they are most commonly used.
What is a gas spring?
A gas spring is a sealed mechanical device that uses compressed nitrogen gas and hydraulic oil to generate force and provide controlled movement.
Within each unit, you’ll find:
- A precision-engineered steel or stainless-steel cylinder
- A piston and piston rod
- High-performance seals
- A pressurised nitrogen gas chamber
- Hydraulic oil for damping
When the rod is pushed into the cylinder, the internal pressure increases. This rise in pressure creates an outward force, enabling controlled opening and closing, and counterbalancing in applications ranging from machine covers to vehicle hatches.
Gas springs are known by different names, such as gas struts, gas props, gas rams, or even gas or pneumatic dampers. In reality, they are all identical, relying on compressed nitrogen gas and hydraulic oil to deliver smooth, controlled motion.
What is a gas strut?
A gas strut is simply another name for a gas spring, most commonly used in cars (hoods, trunks, and tailgates), RVs and motorhomes, boats and marine equipment, and furniture such as adjustable seating and overhead compartments.
Automotive and marine markets in particular use “gas strut,” while industrial sectors more often use “gas spring.” Mechanically, they are identical, both relying on compressed nitrogen gas and hydraulic oil to deliver smooth, controlled motion.
Gas spring mechanism: how does it work?
Gas struts operate using a simple but highly effective internal mechanism:
1. Compressed nitrogen generates force
The cylinder is filled with high-pressure nitrogen. When the rod is compressed into the sealed cylinder, the internal volume decreases and pressure rises. This creates a controlled, outward extension force.
2. The piston regulates speed and movement
Precision channels in the piston meter the flow of gas, allowing predictable movement without sudden acceleration.
3. Hydraulic oil provides damping and smooth end-of-stroke control
Oil slows movement at the end of the stroke, preventing abrupt extension. This is essential for applications like vehicle hatches, machine lids, and access panels.
4. Sealed construction ensures long service life
High-performance seals maintain pressure and protect the internal mechanism from contamination.
Key benefits of gas springs
Gas springs offer several advantages across a wide range of industries. They deliver precise and steady motion that improves safety and ease of use, while providing consistent pre-load force across the stroke. Their compact design allows for high force output in a small footprint, and their sealed construction ensures reliable, maintenance-free operation.
Many variants also offer strong temperature stability and corrosion resistance, making them suitable for demanding environments. With options including compression, traction, lockable, stainless-steel, dynamic, and high-force units, these components provide the versatility engineers need for predictable motion control.
Types of gas springs
There are several types of gas springs available, each offering specific performance characteristics to suit different applications.
Dynamic gas springs
Dynamic gas springs use a cylinder slot to control speed and damping across the stroke. Ideal where the motion profile must be tuned precisely, for example, in automotive tailgates and industrial closures.
Compression gas springs
Compression gas springs are the most common type. The rod extends automatically when force is removed. This type of spring is used in lids, hatches, equipment enclosures, and ergonomic mechanisms.
Lockable gas springs
Lockable variants contain a special internal valve that allows the rod to lock at any point. These gas springs are essential in adjustable furniture, medical devices, and ergonomic systems.
Stainless steel gas springs
Manufactured from corrosion-resistant stainless steel, these components are designed for marine, medical, food-processing, and hygiene-critical environments.
Traction gas springs
Traction gas springs operate in tension, retracting automatically. They are suitable for folding ramps, retractable systems, and applications requiring inward force.
NitroSprings
NitroSprings use high-force nitrogen cylinders compliant with PED 2014/68/EU. They are used in heavy-duty lifting, clamping, tensioning, suspension, and ejection systems.
Custom-designed solutions
Here at Lesjöfors, as well as our extensive range of stock gas springs, we also design and manufacture custom solutions to meet clients’ exact requirements. Our engineers develop gas struts with customized force ratings, materials, mounting formats, and damping profiles.
Common applications of gas springs
Gas struts ensure safe, controlled movement within a wide range of industries:
Automotive
In the automotive sector, gas springs are commonly used in hoods, trunks, tailgates, and other access points. They also support seating adjustments, storage compartments, interior access panels, and a variety of vehicle accessibility systems.
Marine
Stainless-steel gas springs are essential in marine environments, where resistance to saltwater and corrosion is critical. They are typically found in deck hatches, engine covers, seating mechanisms, and offshore doors, delivering long-term performance even in harsh, salt-rich conditions.
Defense
Defense applications rely on heavy-duty gas springs for robust and consistent performance. They support armored vehicle hatches, weapon-system mechanisms, rugged access panels, and a wide range of military field equipment where reliability and durability are essential.
Construction
In the construction industry, gas springs are used in machinery covers, cab-tilt mechanisms, stabilizing systems, and heavy equipment access panels. Their controlled motion helps improve operator safety and equipment reliability on demanding job sites.
Agriculture
Agricultural machinery uses gas springs to assist cabin controls, access hatches, heavy lids, and adjustable implements. Their ability to provide predictable, low-maintenance motion makes them ideal for equipment exposed to outdoor conditions and repetitive use.
Other sectors
Gas springs also play a vital role in medical equipment, industrial automation, aerospace systems, furniture design, and material handling applications. Their versatility and consistent motion control make them suitable for a diverse range of industries.
How to configure and order gas springs
Choosing the right gas strut requires considering the following factors:
- Force range and load behaviour
- Stroke length and cylinder dimensions
- Rod diameter
- Mounting orientation
- End fittings and accessories
- Environmental conditions (temperature, corrosion, hygiene)
Here at Lesjöfors, we’re proud to offer one of the most extensive ranges of gas springs in Europe. Our expert engineers also work closely with clients to define the required parameters and develop custom solutions that meet precise performance requirements.
Stock and custom gas springs for every application
Gas struts perform critical functions across wide-ranging industries. With over 175 years of experience as a spring manufacturer, Lesjöfors is the trusted gas spring partner. We offer thousands of standard gas struts, including variants designed for corrosive environments, adjustable configurations, and lockable options, as well as custom options to meet exact requirements.
Whether you need a standard compression, a stainless-steel variant, a traction gas spring, or a custom-engineered design, our global manufacturing capabilities ensure performance, precision, and long-term reliability.
For tailored support or technical advice, contact us today.
FAQs
A gas spring provides controlled lifting, lowering, and positioning of moving parts using compressed nitrogen and hydraulic damping.
The lifespan varies by use and environment, but high-quality gas springs typically deliver tens of thousands of cycles when installed and maintained correctly.
Common alternatives include gas strut, gas prop, gas ram, pneumatic spring, and gas damper.
Yes. Lesjöfors engineers develop custom gas springs tailored to the required force ranges, materials, stroke lengths, and performance requirements.
Lesjöfors offers one of Europe’s widest ranges, including compression, stainless-steel, traction, lockable, dynamic, and high-force nitrogen springs, along with custom-built solutions.