Metrol Nitrogen Gas Struts - FAQ

Metrol Springs Ltd offer a comprehensive range of gas struts, end fittings and connecting parts from stock.

What is a gas strut?

Gas struts are hydro pneumatic rams. The gas/oil filled units will give smooth controlled movement to lids, hatches and doors. Gas struts are self contained units and maintenance free, when used in accordance to manufacturers guidelines they will give years of trouble-free service.

How a gas strut works

A gas strut consists of a rod that slides in and out of a pressurised sealed tube. The rod has a piston riveted to one end which prevents it from being forced out of the tube when pressurised. The force of the gas strut is provided by the gas pressure acting on the cross sectional area of the rod. The higher the gas pressure, the higher the force of the strut. The piston has a metering orifice which allows the gas to pass from one side of the piston to the other. By altering the size of this orifice the rate of extension can be varied. The oil within the gas strut produces the damping characteristics throughout the stroke, subject to correct orientation. As the rod extends from a compressed position the oil zone will dampen the movement as it reaches its full extension, giving a smooth controlled stop. The damping characteristics can be changed by using different viscosity and volume of oil in the tube.

Characteristics of a gas strut

As a gas strut is compressed the force increases from a high initial value by approximately 30%. This increase can be expressed as a ratio (Rc) values.
Values are given for standard gas strut sizes. By modifying the design of the strut, the ratio can be altered to suit the application.

Where are gas strut used?

Gas struts are used in a wide variety of industries.

Lorries and Trailers
Industrial machinery
Bus and coach
Machine guards
Caravans and Motorhomes
Rooflights and access hatches

And many more, for professional advice on your application, please call us now.

How can a gas strut be used?

Nitro-Struts are used to:

Aid and assist in lifting
Aid controlled movement
Counterbalance when raising and lowering
Damp movement
Support an object in position
Adjust position of an object.

Which gas strut should be used?

There are a variety of Nitro-Struts available to suit different applications.

Fixed Force
Variable Force
Stainless Steel



Sales and technical help: 01604 499332
Alternatively, click here to contact via email or via our fax on 01604 493390.

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New applications, need help or advice on which gas strut to use and what mounting positions to use, call our technical hotline 01604 499332 for advice.