Dual-Action Gas Springs

What Is a Dual-Action Gas Spring?

A dual-action gas spring is a special gas spring solution designed to support, control or balance motion in two functional directions or movement stages.

A standard compression gas spring pushes outward. It is commonly used on lids, hatches, covers, doors and access panels. A traction gas spring works in the opposite direction and pulls components toward each other.

A dual-action gas spring can be engineered around these different motion needs. In some applications, it may support deployment and control return. In others, it may combine compression and traction behavior, include damping, or use a double rod gas spring design to fit a compact mechanism. This makes it different from a normal catalog gas spring.

The first question should not be only: “How many Newtons do we need?” The better question is: “What should the mechanism do during each movement phase?”

Why the Name Can Be Confusing

There is no single global name for this product family. Different industries and catalogs may use different names for similar motion-control concepts.

Common terms include:

• Dual-action gas spring
• Double action gas spring
• Double action cylinder
• Double rod gas spring
• Compression traction gas spring
• Two-way gas spring
• Stow-and-deploy assist gas spring

For technical clarity, dual-action gas spring is usually the best main term. It keeps the product inside the gas spring and motion-control category while still explaining that the part does more than a standard one-direction support spring.

The term double action cylinder can also appear in catalogs, but it is broader and can create confusion with powered hydraulic or pneumatic cylinders. For Newtone’s positioning, dual-action gas spring and double rod gas spring are clearer and safer terms.

A simple definition would be: a dual-action gas spring is a custom gas spring solution used when a mechanism needs controlled assistance in more than one movement phase.

Where Dual-Action Gas Springs Are Used

Dual-action gas springs are used when the movement is more complex than a simple open-and-hold action. The most obvious example is a stow-and-deploy system. A marine mechanism, foldable device or compact equipment assembly may need help when deploying and controlled support when returning to its stored position.

However, the same product idea can be reviewed for many other applications. Possible use areas include:

• Marine stow-and-deploy systems
• Trolling motor lift-assist mechanisms
• Foldable marine equipment
• Special access panels and hatches
• Heavy-duty service covers
• Machine guards with two-stage movement
• Medical equipment covers and adjustable housings
• Food-processing machinery guards
• Military access covers
• Aerospace access systems
• Compact OEM motion systems

The industry can change. The motion problem stays the same. If the mechanism needs controlled movement during both deployment and return, a dual-action gas spring may be worth reviewing.

How Dual-Action Gas Springs Work in Stow-and-Deploy Systems

In a stow-and-deploy system, the moving assembly usually has two important phases. The first phase is deployment. The user wants the mechanism to move from its parked or stored position into its working position with less effort. A gas spring can help reduce the manual force required and make the motion feel smoother.

The second phase is stowing. When the mechanism returns to its stored position, the movement should not feel uncontrolled, heavy or unstable. Depending on the design, the gas spring can help guide, cushion or balance that return movement.

This is why a stow-and-deploy assist gas spring is different from a simple lid support. A simple gas spring might only help a cover stay open. A stow-and-deploy assist gas spring must work with the full movement path of the mechanism. It may need to assist in one phase, resist in another phase, or behave differently through different parts of travel. That is why geometry matters so much. Stroke length, mounting points, rod direction, moving pivots, force level, return speed and end fittings must all be reviewed together.

On one recent project, a compact-equipment OEM building a fold-out marine antenna mount sent us their travel dimensions and their own estimate for the deployment force. When we ran the moment balance on their actual mounting geometry, their planned lower pivot point put the moment arm much closer to the hinge than they had assumed, and their force estimate was meaningfully off. We adjusted the mount point instead of simply raising the spring’s rating, and the finished dual-action strut deployed the mast smoothly while controlling the stow return without needing a separate damper.

What Is a Double Rod Gas Spring?

A double rod gas spring is a special gas spring design where the motion-control function may involve rod movement from both sides of the cylinder body, or a custom internal structure that supports two-phase movement.

This term is important because many buyers describe the product by what they see. If the component has a cylinder body and rod movement from both ends, “double rod gas spring” becomes a natural search term.

A double rod gas spring may be considered when:

• The mechanism needs support in two directions
• The available installation space is limited
• A standard compression gas spring cannot follow the motion path
• Compression and traction behavior are both required
• Return movement needs to be controlled
• The design needs special damping or speed behavior
• The complete mechanism must stay compact

A double rod gas spring is normally not a simple replacement item. It is usually a custom-engineered product built around the application.

Compression and Traction Support in One Custom Concept

A dual-action gas spring can be designed with different motion behaviors depending on the application. One project may need stronger assistance during deployment and lighter control during return. Another may need the opposite. A third may need compression behavior in one direction and traction gas spring behavior in another.

This is why these products are normally discussed as custom projects, not standard catalog parts. Possible design requirements may include:

• Compression force
• Traction force
• Different force values in each movement phase
• Different movement speeds
• Damping in extension
• Damping in compression
• Damping in both directions
• Double rod gas spring configuration
• Special end fittings
• Compact installation space
• Stainless steel construction
• Custom mounting geometry

The right design is not always the strongest design. It is the one that makes the mechanism move safely, smoothly and predictably.

Why a Standard Gas Spring May Not Be Enough

A standard compression gas spring is still the right choice for many applications. If the job is to lift a hatch, hold a cover open or reduce the weight of a lid, a standard gas spring can be simple and reliable.

But some mechanisms need more. A standard gas spring may not be enough when:

• The system has two active movement phases
• Deployment and return both need support
• The mechanism needs compression and traction behavior
• Return speed must be controlled
• Space is too compact for separate components
• A standard spring creates too much force in one position
• The mechanism needs a special force curve
• Damping and force support must be integrated

In these cases, a dual-action gas spring or double rod gas spring may be the better direction. The goal is not to make the part more complicated. The goal is to make the mechanism easier, safer and more controlled for the user.

Fully Stainless Steel Production Option

Newtone can manufacture dual-action gas springs and special gas spring solutions in fully stainless steel construction when the application requires corrosion resistance, cleanability or outdoor durability. See our stainless steel gas springs range for the standard-catalog equivalent of this material direction.

This can be important for:

• Marine equipment
• Outdoor mechanisms
• Food-processing machinery
• Medical equipment
• Laboratory systems
• Military access covers
• Aerospace access systems
• Washdown areas
• High-humidity environments
• Corrosive working conditions

A stainless steel design can help reduce corrosion risk and support longer service life in demanding environments. This is especially important when the product is exposed to saltwater, moisture, cleaning chemicals or outdoor weather.

Not every application needs stainless steel. If the part works indoors in a clean and dry environment, standard material options may be enough. But when exposure is severe, stainless steel should be reviewed from the beginning.

Custom Anodized-Compatible Connection Heads

The connection heads are just as important as the cylinder body. A dual-action gas spring may work inside a compact or visible mechanism where the end fittings must match the surrounding structure. In some applications, the connection heads may need to be produced from materials suitable for an anodized surface process.

Newtone can manufacture special connection heads and end fittings according to the project requirement. These can be designed for compatibility with anodized processes when the application needs a specific surface finish, improved appearance or compatibility with aluminum structures.

This can be useful for:

• Marine aluminum structures
• Premium equipment assemblies
• Aerospace components
• Medical device frames
• Defense equipment
• Custom OEM mechanisms
• Visible connection points

The end fitting is not only an appearance detail. It affects alignment, side-load, installation quality and service life. A clean-looking fitting that cannot rotate correctly may damage the mechanism. A custom connection head that matches the movement path can make the complete assembly more reliable.

Geometry Matters More Than the Product Name

A dual-action gas spring must be designed around the mechanism geometry. The product name alone does not define the right solution. Before production, the movement should be reviewed carefully:

• Where does the mechanism start?
• Where does it finish?
• Which component moves?
• How much stroke is available?
• What force is needed during deployment?
• What force is needed during return?
• Is damping required?
• Is the rod exposed to side-load?
• How much installation space is available?
• Can the end fittings rotate correctly?
• Is stainless steel required?
• Are anodized-compatible heads required?

Side-load is especially important. Gas springs are designed to work mainly in an axial direction. If the rod is forced sideways during movement, the seal, guide and rod surface can wear faster. In a custom dual-action system, this matters even more because the movement path is often more complex than a normal lid support.

When Should You Consider a Dual-Action Gas Spring?

A dual-action gas spring should be considered when a standard compression gas spring, traction gas spring or damper cannot solve the complete movement requirement. It may be the right direction when:

• The mechanism needs support during deployment and return
• The application uses a stow-and-deploy movement
• Compression and traction behavior are both needed
• A double rod gas spring design is required
• Movement speed must be controlled in both directions
• Installation space is too compact for separate components
• The mechanism must feel smooth and controlled to the user
• The product works in marine, medical, industrial, military or aerospace environments
• Fully stainless steel construction is required
• Connection heads must be custom or anodized-compatible

If the movement is simple, a standard gas spring may be the better choice. If the mechanism has two active phases, a dual-action design may solve the problem more cleanly.

What Information Is Needed for a Custom Quote?

To design a dual-action gas spring, the manufacturer needs more than a general force request. The most useful information includes:

• Application photos or CAD drawings
• Open and closed positions
• Deploy and stow positions
• Available installation space
• Required stroke
• Moving part weight
• Mounting points
• Direction of movement
• Required force during deployment
• Required force during return
• Damping requirement
• Desired movement speed
• Material requirement
• End fitting type
• Environmental conditions
• Cycle expectation
• Need for stainless steel
• Need for anodized-compatible connection heads

If an existing product is already used, share its extended length, compressed length, stroke, rod diameter, body diameter, end fitting type and any markings on the part. For stow-and-deploy mechanisms, a short video is often very useful. It shows where the system feels heavy, fast, unstable or uncontrolled.

Frequently Asked Questions About Dual-Action Gas Springs