What is a Lift-o-Mat? Function & Matching Gas Struts (Replacements for Stabilus)

A Lift-o-Mat is a specific design of gas strut that originally became known as a brand name by the company Stabilus, but today often serves as a generic term for flap fittings. It supports the controlled opening and holding open of furniture doors using compressed nitrogen gas. The force is specified in Newtons (N).

What exactly is a Lift-o-Mat?

Technically speaking, a LIFT-O-MAT is a hydro-pneumatic adjustment element. The design consists of a pressure tube (cylinder) and a piston rod with a specialised piston assembly. Highly compressed nitrogen gas is contained inside.

When the furniture flap is opened, the gas pressure pushes the piston rod outwards. This acts like a hydraulic muscle inside the cabinet carcase, taking the weight of the front and lifting the flap upwards without much effort. A small amount of oil in the cylinder provides end-position damping so that the door opens gently and does not slam unchecked against the hinges. Such a gas strut differs fundamentally from simple mechanical lid stays, as it actively assists the movement.

Force specification in Newtons (N) and heavy-duty applications

The decisive technical parameter for selection is the extension force, measured in Newtons (N). As a rule of thumb in furniture making: 10 N corresponds to a load capacity of approximately 1 kg.

For standard kitchen wall units, struts with values such as 200 N or 250 N are frequently used. For large, solid fronts made of MDF or solid wood, however, this is not sufficient. In these cases, gas struts for heavy flaps are required, delivering forces of 300 N, 400 N or even up to 500 N. The exact force selection depends on the flap weight including the handle, as well as the flap height.

Dimensions, standards, and typical values

When replacing a defective strut, the dimensions must match precisely. The most important parameters are:

• Total length (extended): Measured from the centre of one mounting socket to the centre of the other. A common dimension in furniture construction is 268 mm or 245 mm.
• Stroke: The distance that the piston rod can retract (e.g. 90 mm).
• Mounting: The end fittings usually feature a ball joint or an eyelet for mounting onto the ball stud base plate on the carcase. The diameter of the ball socket in standard furniture fittings is often 10 mm.

To blend seamlessly into the furniture, the cylinders are available in various finishes. A gas strut in silver is frequently used in modern kitchens, whilst white or black variants are chosen depending on the interior decor of the carcase.

Usage & selecting the right replacement

If a cabinet door no longer stays open or falls shut on its own, the gas pressure has escaped and the fitting must be replaced. Refilling the gas in these components is not possible.

To identify the correct replacement, a quick look at the text printed on the old cylinder is sufficient. There is usually a sequence of numbers ending in "N" (for example "0250N"). This provides direct confirmation of the required spring force.

Installation is carried out by releasing the metal retaining clips on the ball joints. The new strut is then simply pressed onto the existing ball studs of the flap fittings. For wide flaps fitted with two struts, it is advisable to replace both sides simultaneously to prevent asymmetric strain on the hinges.

Related terms and fittings

In addition to classic gas struts, there are other mechanisms for moving components inside a cabinet. Mechanical flap stays operate via friction and hold the flap at any desired position, but do not actively assist the opening motion.

Another system based on hydro-pneumatic force or strong tension springs is the pull-down wardrobe rail. In this case, rather than opening a door upwards, a clothes rail is swung downwards from the upper section of a tall wardrobe, with the dampers counterbalancing the weight of the garments when swinging it back up.