Heavy-Duty Gas Struts for Ottoman Beds: Sizing 200N to 250N Correctly

October 12, 2025

A gas strut rated at 200 N to 250 N produces enough lifting force to support flaps or lids weighing roughly 20 to 25 kilograms per unit, preventing them from falling shut uncontrollably.

When constructing storage chests, smaller ottoman bed boxes, or solid wall cabinets, fitters and joiners often face the challenge of securely supporting the weight of moving panels. A gas strut acts like a mechanical muscle, taking the self-weight of the flap and holding the opening angle stable. Correct sizing in Newtons (N) is the critical factor. If the strut is too weak, the flap drops shut; if it is too strong, it can hardly be closed or, in the worst case, rips the hinges out of the carcase.

This guide explains the technical parameters for using gas struts in the 200 N to 250 N weight class, how to calculate requirements, and what to look out for during installation.

Key Buying Criteria for Gas Struts

To choose the correct flap stays for a piece of furniture, the weight, leverage, and structural conditions must be matched precisely.

Load Capacity in Newtons (N)

The force of a gas strut is always specified in Newtons. As a rule of thumb in cabinetmaking: 10 N corresponds to a lifting force of approximately 1 kg. A strut with 200 N is therefore designed for a load of around 20 kg. On furniture flaps, two struts are always fitted to ensure symmetry and prevent warping in the material. Two struts rated at 250 N each can therefore support a flap weight of up to 50 kg, provided the lever arm (the depth of the flap) is within the standard range.

Dimensions: Overall Length and Stroke

Alongside force, physical dimensions are vital for opening angle geometry.

Overall length: Usually measured in the extended state from hole centre to hole centre of the mounting brackets (typically 245 mm to 270 mm on standard furniture struts).
Stroke: Describes the distance the piston rod travels into the pressure tube. A typical stroke range is 90 mm to 100 mm. The stroke determines how far the flap can swing open (frequently 75°, 90°, or 110°).

Mounting System and Fixing Points

Transferring force to the carcase requires stable mounting points. Struts are generally supplied with screw-on mounting plates. For carcases made from chipboard or MDF, wood screws with a 4 mm diameter are used. On very heavy flaps requiring gas struts for heavy flaps, the screws must grip deeply enough into the material to absorb the leverage forces when closing (when the strut is compressed).

Overview of Types and Options

Even though the mechanical function remains identical, gas struts can be visually adapted to the furniture design. This is particularly relevant for open shelving systems or glazed fronts.

Standard versions: The housing is made of painted steel, with a piston rod made of chrome-plated metal.
Colour variations: To integrate the fitting inconspicuously into the furniture, different finishes are available. For pale carcases, gas struts in white are suitable, whilst for dark timbers or anthracite decorative boards, gas struts in black are the visually subtler choice. The classic industrial look is achieved with models from the gas struts in silver category.

Please note: A gas strut should not be confused with a pure furniture buffer (soft-close damper). While a gas strut actively exerts force to lift and hold a flap, a soft-close damper merely cushions the closing motion.

Which Strut for Which Application?

Choosing between 200 N and 250 N depends on the material thickness and the dimensions of the flap.

If you are building a storage bench or a toy box made of 18 mm MDF with a lid size of approx. 800 mm x 400 mm, then choose two gas struts with 200 N each. The total weight of the lid is usually 4 to 6 kg here. Due to leverage when closing from the vertical position, this resistance is sufficient for gentle opening and secure holding.
If you are constructing a heavy, deep access flap for an ottoman bed box at the foot end (e.g. made from 22 mm chipboard or solid wood), then opt for 250 N models. The deeper the flap, the larger the lever arm and the more force is required at the mounting point.
If the front flap is additionally weighted with mirrors or thick glass inserts, then the 250 N variant is strictly required to prevent sagging when open.

Installation Advice for Fitters

Installing gas struts requires precision. A discrepancy of just a few millimetres in the fixing points drastically changes the opening angle and the required closing force.

Fit hinges first: Before mounting the struts, the flap must be attached to the carcase with the main hinges. For heavy flaps, robust concealed cup hinges / cabinet hinges with soft-close damping are recommended to support the weight horizontally.
Note installation orientation: Gas struts must always be installed so that the thick pressure tube points upwards and the thinner piston rod points downwards when the flap is closed. Only then is the internal seal pack continuously lubricated by the oil inside the cylinder.
Mark fixing points: Follow the supplied installation instructions precisely for the desired opening angle (e.g. 90°). Measurements are always taken from the inside edge of the carcase.
Assembly: Screw the circular mounting plates to the carcase and flap first. Afterwards, simply clip the strut onto the ball studs of the brackets.

Testing note: Never attempt to compress a 200 N or 250 N strut by hand prior to installation. A force of 20 to 25 kg can hardly be exerted manually in a controlled way. The function can only be tested after installation via the leverage of the flap.

FAQ – Frequently Asked Questions About Gas Struts

What does 200N mean on a gas strut?

The value 200 N (Newtons) indicates the extension force of the strut. Converted, this corresponds to a force capable of lifting or supporting a weight of approximately 20 kg. In furniture construction, this value is needed to balance the weight of a flap including the lever effect.

Can I simply replace a faulty 150N strut with a 250N strut?

No, this is technically not advisable. If you install a substantially stronger strut, the flap will require immense effort to close. Additionally, pressure increases on the hinges and fixing screws in the timber, leading over time to fittings being torn out of the chipboard. Always replace struts with models of identical Newton ratings.

How do I calculate how many Newtons my flap needs?

The exact calculation uses the law of the lever: weight of the flap in kg × 10 × (depth of the flap in mm / 2) divided by the distance from the mounting point to the hinge in mm. For standard wall units, 60 N to 120 N per side is often sufficient. Heavy chest lids or ottoman bed access flaps require 200 N to 250 N per side.

Why cannot the new gas strut be moved before installation?

This is normal physical behaviour. A 250 N strut resists compression with a force of 25 kg. Without the lever arm of the fitted furniture flap, it is extremely difficult for a person to apply this force in an exact linear motion to the thin piston rod without slipping. The strut is not defective; it simply needs to be installed.

Do gas struts require maintenance?

No, they are maintenance-free, closed systems. The only crucial factor is the correct installation orientation (cylinder uppermost when closed) so that the internal seals do not dry out. Furthermore, avoid scratching the piston rod, as scratches would damage the seal during retraction, causing a loss of gas pressure.

Matching Products & Categories

For the complete installation of flaps and heavy lids, you need the right accompanying hardware alongside the appropriate gas strut. Ensure all fittings are fully matched to the weight of the front panel.