Everything You Need To Know About Gas Springs and Gas Struts

Gas springs are versatile hydro-pneumatic (containing both gas and liquid) lifting mechanisms that help us raise, lower and support heavy or cumbersome objects more easily.

They’re most widely seen in various configurations of door hardware, but the potential uses are near limitless. In everyday use, gas springs are now very commonly found in vehicle compartments, supporting adjustable chairs and tables, on all manner of easy-open hatches and panels, and even in small electronic devices.

As the name suggests, these springs rely on pressurised gas - along with some oil-based lubricant - to support or oppose a range of external forces. The compressed gas offers a controlled way of storing and releasing energy as smooth, cushioned movement, transferred via a sliding piston and rod.

They’re also commonly referred to as gas struts, rams or dampers, although some of these terms imply a specific set of gas spring components, configurations and intended uses. Technically speaking, a standard gas spring is used to support objects as they move, a gas damper is used to control or limit that motion, and a damped gas spring tends to handle a bit of both.

With this in mind, how exactly do gas struts and dampers work in practice? Which types are most appropriate in which roles, and what’s the ideal setup for the job you have in mind? In the sections below we’ll explore these and other questions about gas springs, starting with a closer look at how most lifts, struts and dampers function.

Different sorts of gas struts and dampers come in a variety of configurations and components, and the precise mechanics of any given spring will be defined first and foremost by its intended use. Gas springs found in vehicle compartments will most likely be set up differently to those used on doors, chairs, electrical goods or industrial platforms - but all have some key elements in common.

To better understand how gas struts work, it’s helpful to picture a standard bicycle tyre pump. Like most manual hand pumps, gas springs and dampers feature a piston and rod mechanism passing back and forth through a tight-fitting tube. Unlike the open-ended tube of a pump, though, the cylinder of a gas spring is sealed, so the volume of gas inside remains constant.

The piston in a gas strut allows a certain amount of this gas to pass around or through it, maintaining a balanced internal pressure while creating two varying pockets of different volumes and surface areas. By limiting the ease of gas flow through the piston one way or the other, manufacturers can adjust the force required to move it in a given direction.

The extent to which this ease of flow is balanced or biased, along with the overall pressure of gas and fluid contained in the tube, is what makes different types of gas strut better suited to either supporting, accelerating or damping movement.

Gas springs for doors

Given the myriad door types that benefit from gas spring applications, it’s no surprise that there are almost as many options for which sort of strut will fit which scenario.

Household, school or workplace doors usually incorporate some sort of traction or pull-type gas spring, to help them open easily under pressure but return quickly to a closed position when not in use. Conversely, cabinet doors and access hatches often require the exact opposite function, allowing considerable weight to be lifted easily, and remain fully open until manually pulled shut again.

In either scenario, a locking gas spring might also be useful, enabling the door to hold itself in place midway between fully open or closed. Certain doors - such as those with folding mechanisms - may even require a variable speed gas strut, to allow for smooth operation as different parts of the door move at different rates, and to dampen movement as partitions slide into one another.

As with all such fixtures, the correct type of door gas struts to choose will depend entirely on what job you want them to do once mounted. Gaining a clear idea of the desired action and activation force is always the best place to start when figuring out which gas spring product will best suit your needs.

Gas springs for cars

Some cars will incorporate multiple sets of gas springs into the design of their various hoods, panels and compartments, but by far the most common usage is in boot-lifting mechanisms. In particular, nearly all hatchbacks and estate cars will have gas struts affixed to the rear assembly, helping to lift, support and lower their heavy tailgates smoothly and effortlessly.

In fact, the action on most car-fitted gas springs is subtle enough that many drivers don’t realise they’re actually helping to raise the tailgate, as opposed to just holding it in place once it’s up. It’s easy to tell how much heavy lifting these fixtures do once they start to wear and degrade, though - especially with some estate-type rear doors, which can feel remarkably heavy if their gas struts are overdue for replacement.

Gas springs for chairs

The gas springs commonly used for office chairs are generally arranged in more of a ‘damping’ configuration, where greater resistance is met as the chair is lowered, and less as it’s raised. This cushions the downward movement of the seat when you’re in it, but allows it to spring back to its starting position with no manual force when empty.

Office chair gas struts are nearly always lockable one way or another, although it’s worth noting that the locking mechanism is sometimes entirely separate from the spring itself. In these cases, rather than being a built-in feature of the strut, the lockable component functions more like a quick-release clamp positioned around the sliding central column.

Both types tend to be equally effective at holding a comfortable position, and are similarly easy to adjust for the user.

From the handful of examples given above, it’s clear that there are multiple product types and configuration options available when it comes to installing gas springs or dampers on all manner of hardware.

In this section, we’ll look more closely at the different types of gas struts on offer, and at how to decide which sort of spring you might need to get the job done properly.

How to calculate the right gas spring

For the most part, picking out the most suitable type and gauge of gas strut will depend on knowing some basic information about the measurements, angles and ratios of the doors, windows, cabinets, compartments, hatches, platforms and panels you’re looking to move, support or restrict.

Key data to bear in mind when figuring this out includes the dimension and weight of moving parts (particularly their unsupported span), the degree of force you’ll ideally require to move them (anywhere from 50-2500N in many common cases), and where their centre of gravity will lie as they fully open and close.

Armed with this information - which isn’t nearly as difficult to measure (or even estimate) as it may sound! - you can then use a gas spring calculator or sizing chart to judge which type and gauge of gas strut will deliver the effect you’re looking for.

Alternatively, of course, you can always contact our expert customer service team for helpful advice and assistance.

As you’d expect from such a diverse and multifaceted product line as gas struts and components, there is a huge range of manufacturers and suppliers available - and, as ever, quality can vary considerably.

Even after you’ve taken the time to research and locate fittings, fixtures and accessories that are all fully compatible with one another, it can be difficult to feel assured you’re getting reliable product advice, engineering support and aftercare when liaising with multiple different manufacturers. For this reason, we highly recommend the full suite of Camloc gas spring systems.

Camloc gas springs

Camloc offers a comprehensive, fully compatible range of gas springs, struts and damper systems, ideally adapted to a wide variety of high-performance uses and settings. After nearly three decades in the business, they’re now a go-to brand across many exacting industries and sectors, including:

• construction
• military
• medical
• distribution
• leisure
• automotive

In addition, buyers of high-quality Camloc springs and gas strut products benefit from advanced engineering support, free technical advice, flexible custom-made designs and full compliance with the latest ISO 9001 industry standards.

The standard traditional version of compression springs are usually based on the classic spring design we’re all familiar with: a coiled length of exposed steel wire that can be compressed more tightly against itself when an external force is applied to either end. They’re used in countless everyday mechanisms, from ballpoint pens to mobile phones, electronics and vehicle suspension systems.

As the downward force exerted on a compression spring increases, the coiled wire stores progressively more and more energy. It will only release that energy, as either a sudden or a gradual ‘push back’ movement, once the force holding it down is removed or sufficiently reduced.

In terms of spring function, this spring is usually deployed as a type of damper - it inhibits the downward motion of any force applied on top of it, to an extent defined by the gauge and stiffness (or spring rate) of the wire coil. Gas springs can perform much the same role, although they’re far more versatile in general.

Gas struts and rams designed to act as dampers are able to withstand much higher compressive forces than exposed steel wire versions, due to the compressive properties of pressurised gas. This makes them ideal for use in a range of heavy-duty industrial settings, where the weight of the platform or moving part exerting force on the spring would be too great for exposed steel coils to push back effectively.

However, as we’ve seen above, gas springs can also be configured and combined with numerous accessories to serve a range of other purposes, from holding raised platforms and objects in position to offering smooth, effortless movement in any given direction. This multi-directional function is one of the other key strengths of gas struts: a car hatchback, for example, that uses traditional steel springs would move very rapidly in one direction or the other, but require excessive force to return to its original position.

The fact that gas pistons, lift struts and compression springs can be configured to raise, lower, support, damp or limit movement makes them far more versatile tools in most scenarios, and highly adaptable for an almost limitless range of household and workplace applications.

Gas springs, struts and dampers are incredibly widely used today, with applications across more industries and sectors than we could hope to name. They’re found at all sorts of scales and spring ratings, performing functions that range from supporting massive industrial platforms, to enabling the smooth self-closing mechanism of a high-end DVD player.