How to Choose the Right Gas Struts for Your Project

Whether you're lifting the door on a canopy, building a toolbox lid, or designing a storage hatch, choosing the right gas strut can make all the difference. A well-matched pair of struts provide smooth, controlled, motion and reliable support — whilst making the wrong selection can lead to frustrating installs, premature wear, or safety issues. 

At Selectlok we recommend that your gas struts be installed by a qualified auto professional and so we have not included installation guidelines in this guide. 

We’ll walk you through everything you need to know to pick the perfect gas strut for your project — from understanding force ratings to getting the right size and preparing for installation. 

What Are Gas Struts? 

Gas struts (also called gas springs) are pressure-loaded cylinders that assist in lifting and holding open panels, lids, and doors. They’re commonly used in: 

They work by forcing a metal shaft (piston) to slide (in and out) and compress a highly pressurised gas contained within the outer cylinder body (via a system of rubber seals and directional valves) to provide a smooth and assisted force to aid in the lift and/or closing action of any number of applications — making your setup easier and safer to use. 

How to Select the right Gas struts to ensure they are fit for use? (Light, Medium or Heavy Duty) 

Gas struts are generally broken down into three or four main categories and are rated by length, shaft diameter as-well-as their pressure-force/Newtons (N) or possibly, even what sort of ends/connectors are being used.   

A great place to start is to figure out whether you require a strut that is going to perform relatively light-duties and is there primarily only to offer support or whether you need something more substantial that will assist you in lifting heavy or cumbersome lids and doors, etc. The easiest way to do this is to look at the correlation between shaft diameters and the pressure/force range (N) of a given strut.  

Heavy-Duty Gas Struts:  

Best for: 

Heavy-duty struts are built to handle excessively heavy loads and rough conditions. They’re ideal for higher cycling usage both in outdoor environments and setups where strength and reliability are non-negotiable. 

Tip: Always ensure you have calculated the optimal strut length and mounting position (as-well-as the force to shaft diameter ratio [N:Dia] is determined so-as to safely and effectively assist in supporting full weight of the load whilst preventing excessive; twisting, strain or catastrophic failure. 

Selectlok Pick: 

Shop Heavy-Duty Struts at Selectlok 

Medium to Heavy-Duty Gas Struts:  

Best for: 

Medium to heavy-duty struts really blur-the-lines between the two categories. They’re ideal for outdoor environments and are perfect for assisting with doors that are more substantial in size and weight yet still provide durability and longer life-expectancies than standard medium-duty gas struts. 

Tip: Always ensure struts are mounted in the correct placements to prevent premature wear, safety issues or inadequate support. 

Selectlok Pick: 

Medium-duty struts strike the balance between lifting power and smooth control. They’re great for everyday access where weight is moderate. 

Medium-Duty Gas Struts: 

Best for: 

Tip: Choose quick-connect ends to make installation easier. 

Selectlok Pick: 

Explore Medium-Duty Struts 

Light-Duty Gas Struts:  

Best for: 

Light-duty struts offer reliable lift and gentle support — perfect when you want subtle motion control in tight or indoor spaces. 

Tip: Even small struts need to be installed correctly to avoid bending. 

Selectlok Pick: 

Browse Light-Duty Struts 

How to Choose Your Gas Struts  

When choosing what gas struts to pair with your project or build, it is imperative that you select a variant that is going to be best suited for your application.  

This typically, can require a series of calculations based on two or more of the factors above and often comes down to how heavy your lid or door is, the external dimensions and how much assistance is required when in use. 

Calculating the Correct Variant to Use 

To work properly, your gas strut must match the size and travel distance of your lid.

Here's how to measure it:

1. Measure the Lid Height - Measure the distance from the hinge to the fully open position. A good rule of thumb is for your gas strut to be around 60–70% of the lid height.
   
   
2. Know Your Stroke Length - This is how far the strut travels between open and closed. Make sure it’s long enough to open fully, but short enough to close completely without bottoming out.
   
   
3. Plan the Mounting Angle - Most struts work best when mounted at a 30–45° angle from horizontal when extended. This helps with smooth operation and even pressure

(Please refer to the infographics below) 

Selectlok offers lengths from 195mm to 920mm, with a wide variety of force ratings — ideal for DIY projects of any scale. 
 

See the Full Range of Gas Struts 

What to Prepare Before Installation 

A smooth install starts with good prep. Here’s what you’ll need: 

Final Tips for Success 

Need Help Finding the Right Fit? 

Not sure what you need? The team at Selectlok is here to help — with expert advice, custom pressure fills, and fast shipping across Australia. 

Whether you're upgrading your canopy or building something from scratch, the right gas strut will make your project easier, safer, and more professional.