Replacing a Faulty Stabilus Lift-O-Mat: How to Find the Right Replacement

January 26, 2026

A faulty gas strut must always be replaced with a model featuring an identical extension force in Newtons (N) and an exact matching overall length to keep the flap properly balanced.

When a kitchen wall unit door no longer stays open on its own or slams shut, the built-in gas strut is usually defective. In furniture construction, models like the Stabilus Lift-O-Mat have been the technical standard for upward-opening fronts for years. Inside the cylinder is nitrogen gas stored under high pressure. Over the years or due to seal wear, this gas slowly escapes, reducing the lifting force.

For installers or joiners, the challenge during replacement is identifying the exact matching spare part. An incorrect strut inevitably leads to mechanical malfunctions and, in the worst-case scenario, can rip the hinges out of the carcase. In this guide, you will learn the technical criteria required to determine the correct replacement for your LIFT-O-MAT and how to carry out the installation properly.

Key Purchasing Criteria for Replacement

Selecting the right replacement strut does not require guesswork, but rather reading or measuring three clear technical factors.

Extension Force in Newtons (N)

The force with which the piston rod is pushed out of the cylinder is specified in Newtons. This is the most critical parameter when replacing the part. If the force is too low, the flap will drop shut under its own weight. If it is too high, closing the front requires considerable effort, placing permanent strain on the fittings.

Typical values for standard furniture flaps (such as microwave cupboards or wall units) are 200 N or 250 N. On original parts, the exact rating is printed directly onto the cylinder. Look for a number ending with "N", such as "0250N" or "200 N". Once you have identified this number, you know precisely which gas strut you need.

Overall Length and Stroke

In addition to force, the geometry must be correct. The overall length is always measured in the fully extended state. The measurement is taken from the centre of one mounting eye to the centre of the other mounting eye. Common lengths in furniture making include 245 mm or 268 mm.

The stroke refers to the distance the piston rod can travel inside the cylinder. It defines the maximum opening angle of the door. A replacement strut must match the original in overall length and stroke to within a few millimetres; otherwise, the mechanism's kinematics will jam.

Mounting and Fixing Type

The end fittings of the strut, often called socket ends, must fit the mounting plates screwed to the carcase and the front. In most cases, these are ball sockets clipped onto a ball stud, typically with a diameter of 10 mm. This ball joint connection allows the strut to compensate smoothly for the slight rotational movement when the flap opens.

Overview of Types and Options

Even though the fundamental function is the same, different strut versions exist depending on the application and furniture design.

Standard vs. Heavy-Duty Versions

For standard fronts made of chipboard or lightweight MDF with a width of 600 mm, standard struts ranging from 150 N to 250 N are perfectly adequate. However, if dealing with large-format doors, solid timber, or fronts with integrated glass panels, the weight increases significantly. In these instances, specialised gas struts for heavy flaps are used, handling forces of 300 N, 380 N, or more. With such weights, the load-bearing flap fittings must also be solidly sized and anchored deeply into the carcase.

Appearance and Colour Finishes

In modern furniture construction, the interior aesthetics of cabinets play an important role. While silver metal cylinders were used almost exclusively in the past, struts are now matched to the carcase decor. To create a cohesive look, you can choose between different finishes:

Gas struts in silver for classic white or grey carcases.
Gas struts in black for dark timbers or anthracite interiors.
Gas struts in white for a seamless look in bright kitchens.

Related Systems: The Wardrobe Lift

A technical relative of the cabinet strut is the wardrobe lift. Gas struts also work behind the scenes here to move heavy loads. However, this is a complete lifting mechanism for tall wardrobes, where the hanging rail swings downwards on two lever arms. The struts in these systems are significantly larger and calibrated with much higher force than the compact cylinders used in kitchen wall units.

Which Model for Which Application? (Decision Guide)

If the print on the old strut has become unreadable, you will need to calculate or estimate the required force. The rule of thumb: the strut force must counterbalance the door weight precisely, taking the leverage effect into account.

For small fronts (e.g. 30 cm height, lightweight finish): Choose models around 150 N.
For standard kitchen flaps (e.g. 40 cm height, MDF): 200 N or 250 N are standard here.
For large or heavy fronts (e.g. 50 cm height, solid timber): Choose models from 300 N up to 380 N.

If you do not know the exact Newton rating, you can make a rough calculation. Weigh the detached flap. You need approximately 10 N of holding force per kilogram of door weight. However, because the flap acts as a lever, this value is multiplied by a factor based on the door height. For precise specification, manufacturers of flap stays provide reference charts where you can cross-reference the front weight and height to find the correct strut rating.

Important principle: Always replace both struts on a door simultaneously. Even if only one cylinder seems faulty, the second will have already lost pressure. Replacing only one side leads to asymmetrical stress on the hinges, which causes the door to warp over time.

Installation Guide: How to Replace the Strut

Replacement is as simple as clicking a seatbelt into place — the socket snaps onto the ball stud with gentle pressure. All you need is a flat slotted screwdriver and a helper to support the flap during the process.

Secure the door: Open the front fully and have a second person support it in its highest position.
Release the retaining clip: Place the slotted screwdriver against the small metal clip on the plastic head of the old strut. Lever the retaining spring up slightly (do not remove it completely, just lift it).
Detach the strut: Lifting the spring expands the ball socket. Pull the strut sideways off the ball stud. Repeat this on the other end of the cylinder.
Fit the new strut: The new cylinder is usually supplied ready to install. Place the ball socket onto the ball stud on the carcase and press firmly until it clicks audibly into place. Lifting the clip beforehand is usually not necessary when fitting.
Check functionality: Repeat the procedure on the second strut. Open and close the flap several times to verify smooth movement and correct holding force.

FAQ – Frequently Asked Questions About Replacing Struts

Where do I find the force rating (Newtons)? On almost all models, the Newton rating is stamped directly into the metal cylinder or printed on it. Look for a number followed by an "N". Typical markings are "0200N", "250 N", or "320N".

Can I fit a stronger strut so the flap stays open better? No. The extension force must be matched precisely to the weight of the front. An excessively strong strut (e.g. 320 N instead of 200 N) will cause the door to fling open aggressively and make closing it very difficult. The continuous tension can pull the fixing screws out of the chipboard.

Do both gas struts always need to be replaced? Yes. Gas struts are subject to natural wear. If one side fails, the other is usually near the end of its service life as well. Replacing only one side leads to uneven force distribution and will warp the cabinet door.

How do I measure the length correctly? Always measure the strut when it is uninstalled and fully extended. The correct measurement is taken from the centre of the top fixing hole (or ball socket) to the centre of the bottom fixing hole.

What is the difference between a gas strut and a furniture damper? These components perform opposite tasks. A gas strut (such as the Lift-O-Mat) actively pushes a flap upwards and keeps it open with constant force. A furniture damper (soft-close cylinder), on the other hand, is a purely passive component on hinges or drawer runners that merely decelerates the closing movement to prevent slamming.

Matching Products and Categories

To find the exact replacement for your furniture unit, navigate directly to the appropriate category. You can filter the struts by length and Newton force: