Changzhou Colewell Machinery Co., Ltd.

A gas strut provides controlled motion and support for doors, hatches, lids, and equipment across industries. Proper measurement ensures correct replacement and optimal performance for your application. These pneumatic devices contain pressurized gas that creates force for lifting, lowering, and positioning loads.

Equipment failures from incorrect gas strut specifications cost businesses thousands in downtime. Industrial maintenance studies show that 65% of gas strut replacements fail due to improper sizing, leading to equipment damage and safety hazards.

You benefit from accurate gas strut measurement by ensuring proper function, extending equipment life, and maintaining safety standards. The global gas spring market continues to grow as industries demand reliable motion control solutions.

Key Takeaways

• Gas strut measurement requires three critical dimensions: stroke length, extended length, and compressed length

• End fitting types and dimensions must match your mounting hardware for proper installation

• Force ratings determine lifting capacity and must align with your load requirements

• Lockable gas struts require additional specifications for the locking position and release mechanism

• Professional measurement and documentation prevent costly installation failures and equipment damage

Gas Strut Measurement Overview

What Are Gas Struts?

Gas Struts are pneumatic devices that use compressed gas to provide controlled force for lifting, lowering, and positioning applications. These components consist of a cylinder containing pressurized gas, a piston rod that extends and retracts, and end fittings for mounting. You find gas struts essential in automotive applications, industrial equipment, furniture, and medical devices.

The system works through gas pressure acting on a piston inside the cylinder. When you apply force, the piston moves, compressing or expanding the gas volume. This creates controlled motion with consistent force throughout the stroke range.

Note: Gas struts differ from mechanical springs by providing constant force rather than variable force that increases with compression.

Common applications include:

These specifications help you understand the range of gas strut options available for different applications and load requirements.

How Gas Struts Work

Gas struts operate through pressurized gas contained within a sealed cylinder. The gas pressure acts on a piston connected to the extending rod, creating a force that supports or moves loads. When you compress the strut, gas pressure increases, providing resistance. During extension, gas pressure decreases, reducing force output.

Key operational principles include:

• Pressure differential between cylinder chambers creates a directional force

• Sealed construction maintains gas pressure throughout the service life

• Controlled flow through internal valving manages extension and compression speed

• Temperature compensation adjusts pressure for environmental conditions

You achieve optimal performance through proper gas strut selection, matching your specific requirements:

Gas struts provide consistent force output regardless of position within the stroke range. This characteristic makes them ideal for applications requiring steady support or controlled motion.

You can configure mounting orientations to suit various equipment designs and space constraints.

The sealed system requires no maintenance under normal operating conditions, providing long-term reliability in demanding applications.

Tip: Many industrial automation systems rely on gas struts for precise positioning and load support in manufacturing processes.

Recent developments in gas strut technology include:

• Advanced sealing materials extend service life in harsh environments

• Smart gas struts with integrated sensors provide position feedback for automated systems

• Lockable Gas Struts offer mid-stroke positioning for adjustable applications

• Environmental considerations drive the development of eco-friendly gas alternatives

When planning gas strut applications, you should:

• Calculate exact load requirements, including weight and moment arms

• Consider environmental factors like temperature, humidity, and chemical exposure

• Plan mounting locations with adequate clearance for full stroke operation

• Select appropriate end fittings that match your mounting hardware

• Account for cycle life requirements based on usage frequency

Gas struts provide the reliability, precision, and safety you need for controlled motion applications across industries. You can support heavy loads, control motion speed, and maintain position with properly selected components.

Core Measurement Parameters

Stroke Length

Stroke length represents the total distance the piston rod travels between fully compressed and fully extended positions. This measurement determines the maximum opening angle or travel distance your equipment can achieve. You calculate stroke length by subtracting the compressed length from the extended length.

Critical measurement process:

1. Compress the gas strut completely to its shortest position

2. Measure the distance between mounting center points (dimension A)

3. Extend the strut fully to its longest position

4. Measure the distance between mounting center points (dimension B)

5. Calculate stroke length: B-A = stroke length

Important: Stroke length directly affects your equipment's range of motion. Insufficient stroke prevents full opening, while excessive stroke may cause interference with surrounding components.

Extended Length

Extended length measures the total distance between mounting center points when the gas strut is fully extended. This dimension ensures your equipment reaches its maximum open position without the strut bottoming out or failing to provide adequate support.

You measure extended length by positioning the strut in its fully extended state and measuring the straight-line distance between the centers of both end fittings. This measurement includes the cylinder body plus the fully extended piston rod.

Tip: Record extended length in millimeters for precision, as small variations can significantly impact equipment function.

Compressed Length

Compressed length measures the minimum distance between mounting center points when the gas strut is fully compressed. This dimension ensures your equipment can close completely without the strut preventing proper closure or occupying excessive space.

Measure compressed length with the strut in its shortest position, recording the distance between end fitting centers. This measurement represents the cylinder body length plus the minimum piston rod extension.

End Fittings and Mounting

Common Fitting Types

Gas strut end fittings provide the mechanical connection between the strut and your equipment. You'll encounter several standard fitting types, each designed for specific mounting requirements and load conditions. Ball socket fittings offer flexibility for angular movement, while eyelet fittings provide rigid connections for heavy-duty applications.

Ball Socket Fittings:

• Allow angular movement during operation

• Accommodate mounting misalignment

• Common in automotive and furniture applications

• Available in various ball diameters (6mm, 8mm, 10mm typical)

Eyelet Fittings:

• Provide a rigid mounting connection

• Handle higher loads and side forces

• Used in industrial and heavy-duty applications

• Require precise mounting hole alignment

Threaded End Fittings:

• Offer adjustable mounting length

• Allow custom mounting configurations

• Common thread sizes: M6, M8, M10

• Require compatible threaded mounting points

Fitting Dimensions

Accurate fitting dimensions ensure proper installation and safe operation. You must measure critical dimensions, including ball diameters, eyelet inner dimensions, and thread specifications. Mismatched fittings can cause installation failure or premature wear.

Ball Socket Measurements:

• Ball diameter (measured at the widest point)

• Socket depth and opening diameter

• Mounting stud diameter and length

Eyelet Measurements:

• Inner diameter of mounting hole

• Eyelet width (metal thickness)

• Overall eyelet dimensions

Threaded End Measurements:

• Thread diameter and pitch (e.g., M8x1.25)

• Thread length and engagement

• Hex size for installation tools

Note: Always verify fitting compatibility with your mounting hardware before ordering replacement gas struts.

Force Rating Determination

Force rating indicates the extending force your gas strut provides, measured in Newtons (N) or pounds (lb). This specification determines whether the strut can adequately support your equipment weight and provide smooth operation. Incorrect force ratings cause poor performance or equipment damage.

Force Rating Identification Methods:

1. Label Reading: Check cylinder body for printed or engraved force ratings

2. Calculation: Determine the required force based on load weight and mounting geometry

3. Testing: Use a force gauge to measure the actual strut output

4. Supplier Consultation: Provide application details for professional recommendation

Force Selection Guidelines:

• Match or slightly exceed calculated requirements

• Consider safety factors for dynamic loads

• Account for friction and binding in the mechanism

• Evaluate force requirements at various positions

For lockable gas struts, specify both extending force and holding force at the locked position. These specialized components require additional force calculations for proper selection.

Lockable Gas Struts

Locking Mechanisms

Lockable gas struts provide the ability to stop and hold position at any point within the stroke range. These specialized components combine standard gas strut operation with mechanical locking systems that prevent unwanted movement. You control locking through various release mechanisms designed for specific applications.

Common locking types include:

• Cable Release: Remote operation through flexible cable connection

• Button Release: Direct manual operation at the strut location

• Rotary Release: Twist-action mechanism for secure engagement

• Lever Release: Ergonomic handle for frequent operation

Tip: Lockable gas struts are essential for adjustable workstations, medical equipment, and applications requiring precise positioning.

Locking Position Specifications

When specifying lockable gas struts, you must define the required locking positions and holding forces. These parameters ensure the strut can maintain position under your specific load conditions while providing smooth operation throughout the stroke range.

Key specifications include:

• Locking range: Portion of the stroke where locking is available

• Holding force: Force required to maintain locked position

• Release force: Force needed to activate release mechanism

• Locking precision: Accuracy of position holding under load

Application Considerations

Lockable gas struts require careful application analysis to ensure proper performance. Consider operating frequency, environmental conditions, and user accessibility when selecting locking mechanisms and specifications.

Design factors include:

• Operator access to release mechanism location

• Environmental protection for outdoor or harsh conditions

• Cycle life requirements for frequent adjustment applications

• Safety considerations for fail-safe operation

Selection and Installation Guide

Load Calculation

Accurate load calculation ensures your gas strut provides adequate force for smooth operation without overpowering the mechanism. You must consider the actual weight being supported, the mounting geometry, and any additional forces from friction or binding.

Basic force calculation:

1. Determine the weight of the supported component

2. Measure the distance from the hinge point to the center of gravity

3. Measure the distance from the hinge point to the gas strut mounting

4. Calculate the required force using lever arm principles

Formula: Required Force = (Weight × Distance to CG) ÷ Distance to Strut

Additional considerations:

• Safety factor (typically 1.2-1.5)

• Dynamic loads from operation

• Environmental effects on gas pressure

• Friction in the mechanism components

Installation Requirements

Proper installation ensures safe operation and maximum service life. You must follow the manufacturer's specifications for mounting, orientation, and environmental protection. Poor installation practices lead to premature failure and safety hazards.

Installation best practices:

• Mounting orientation: Rod down for maximum life in most applications

• Alignment: Ensure smooth operation without binding or side loading

• Protection: Shield from damage and environmental contamination

• Documentation: Record installation details and specifications

Maintenance and Inspection

Regular maintenance preserves gas strut performance and identifies potential issues before failure. You should establish inspection schedules based on usage frequency and environmental conditions.

Maintenance tasks include:

• Visual inspection for damage, leakage, or contamination

• Operation testing to verify smooth motion and proper force

• Seal condition assessment for gas leakage

• Mounting security verification for all connection points

Important: Replace gas struts showing signs of gas leakage, binding, or reduced force output to prevent equipment damage or safety hazards.

Conclusion

Accurate gas strut measurement ensures proper equipment function, safety, and longevity. Understanding stroke length, extended length, compressed length, and force requirements allows you to select the right components for your application. End fitting compatibility and environmental considerations complete the specification process.

Professional measurement and documentation prevent costly installation failures and equipment damage. Whether you need standard gas struts or lockable gas struts, proper specification ensures optimal performance and reliability.

For complex applications or custom requirements, consult with experienced gas strut suppliers who can verify your measurements and recommend appropriate solutions for your specific needs.

FAQ

How do you measure gas strut stroke length?

Compress the strut fully and measure between mounting centers (A), then extend fully and measure again (B). Stroke length equals B minus A.

What happens if you use the wrong force rating?

Incorrect force can cause equipment malfunction, damage, or safety hazards. Too little force fails to support loads, while excessive force may damage mechanisms.

Can gas struts be mounted in any orientation?

Rod-down orientation typically provides the longest life, but mounting flexibility depends on specific strut design and application requirements.

How often should gas struts be replaced?

Replace gas struts when they show reduced force, gas leakage, or binding. Service life varies from 50,000 to 2 million cycles, depending on application and quality.

What's the difference between lockable and standard gas struts?

Lockable gas struts include mechanisms to stop and hold position at any point in the stroke, while standard struts provide continuous force throughout their range.