How Gas Springs Work

Proven and Reliable

Gas springs are a proven and reliable method of counterbalancing large covers and objects. They offer ideal capabilities for safely lifting, lowering and positioning heavy or cumbersome objects.More versatile than mechanical springs, gas springs offer your product the advantages of speed-controlled dampening, cushioned end motion, simple mounting, compact size, flat force curve, and a wide range of available forces.

Simple Construction

Essentially, a gas spring is a sealed cylinder consisting of only a few basic components: rod, tube, piston, seals and end attachments. It contains pressurized inert gas and a small amount of oil.Although we use standard components, we custom design and manufacture each product to meet specific needs.

Simple Operation

The internal pressure of the gas spring greatly exceeds atmospheric pressure. This pressure differential exists at any rod position and generates an outward force according to the equation: Force=(Pgs-Patm)x(rod area)

Gas-Springs-figure 1

As the rod is pushed into the tube chamber, some of the gas volume is displaced, slightly increasing the internal pressure…Pgs.This causes forces to be a function of stroke as shown in figure 2.Actual gas spring forces are also governed by frictional effects(both static and dynamic).

Repeatable Linear Forces

Output forces of a gas spring are factory-set to customer specifications. Each gas spring is pressurized to obtain the desired working force P1and dependent forces P2, P3and P4.

As shown by the diagram in figure 2, when an external compressing force exceeds the extended force of a gas spring (P3), the rod compresses into the cylinder. When the extension force (P2)exceeds the external force applied, the gas spring extends.Frictional effects are represented by f.

Gas-Springs-figure 2

The slope of the Force/Stroke diagram is represented by P2/P1which is termed a Force Ratio. This can be varied from 1.1 to 1.6 in a given spring, depending on application requirements. Standard gas springs have Force Ratios typically ranging from 1.2 to 1.4.


During motion of the piston through the tube, versatile dampening capabilities are generated by forcing the gas and oil to meter through the piston.

Gas-Springs-figure 3

Our patented Labyrinth pistons use a “maze” path to generate variable degrees of dampening depending on the effective length of the maze. This allows the Labyrinth path cross-section to be larger, ensuring more reliable operation than tiny single-orifice pistons.

When the piston changes direction, the piston seal flips and can change the flow path through which the gas and oil pass. Most gas springs dampen during extension for controlled opening motion, but they bypass dampening during compression for easier closing. Compression dampening is optional.

Most applications perform more smoothly if the gas spring is oriented with its rod end down. This allows the more effective oil dampening to occur later to provide end cushioning.

Dampers for speed control only, without counter-balancing, are also available. Basic construction is essentially the same as the gas spring except there is much more dampening oil and no internal pressure charge. Dampening in widely variable amounts can then be provided in extension, compression or both directions.

Updated: 8/6/2020

Helpful Links

Are you looking for bearings?

About Monroe


Over 60 years of manufacturing experience to best serve our customers



Monroe provides custom manufacturing solutions to clients throughout the world


Value Adds

Our knowledge, customer service & processes are structured to reduce delivery times, improve quality & cut costs



Monroe is committed to customer satisfaction, we strive for continuous improvement in our products and our people.


The information contained in this website is for general information purposes only. The information is provided by Monroe Engineering, LLC, Inc. (Monroe) and while we endeavour to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk. All users should evaluate product suitability for each intended application of that product under actual use conditions. In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from this information.