Window hardware: how it works, what it supports and how to choose it according to the type of wall opening

Window hardware is the mechanism that opens, closes and holds the sash, and it sets how many kilos the sash can weigh, how many operations it can take and how it ventilates. It is chosen by three data points: the test class of the EN 13126 series, the maximum sash weight declared by the manufacturer and the corrosion protection.

The profile and the glass are what you see; the hardware is what you feel every day, when you turn the handle. If it fails or falls short, the window sags, rubs or stops closing properly, however good the profile is. That is why it pays to know which parts make up window hardware, what the numbers on the data sheets mean and what to ask before signing the order.

This guide gathers data published by window system and window hardware manufacturers, by the trade press and by standards bodies. We do not compare brands: each figure is attributed to its manufacturer and applies to a specific model, under its own conditions.

The short answer: window hardware is made up of hinges, a tilt stay, an espagnolette with locking points and a handle. The EN 13126 series defines how it is tested; according to Roto, class H3 equals 20,000 cycles and H2 equals 10,000. The weight a sash can take is limited by the weakest link in the assembly: the Cortizo COR 70 concealed-sash data sheet declares 160 kg per sash, and the hardware of the manufacturers consulted declares between 130 and 300 kg depending on the model. Against coastal salt, corrosion class 5 requires 480 hours of salt spray, according to Interempresas.

What parts make up window hardware and what is each one for?

A tilt-and-turn hardware set brings together four groups of parts: those that hang the sash, those that guide it, those that close it and the handle that moves everything. Window hardware for side-hung windows has the same parts without the tilt stay.

The more locking points, the more even the pressure on the gaskets. On a side-hung window, the Ventanas Cortizo guide explains that the sash presses against the gaskets, and that is why it usually gives more weathertightness and insulation.

Visible hardware and concealed hardware

With visible hardware, the hinges and the tilt stay can be seen when the sash is closed. With concealed hardware they are hidden in the joint between sash and frame. Some heavy sashes use concealed hinges: Maco declares 150 kg for its Multi Power range, and Roto states up to 180 kg on timber profiles for its NX C concealed hinge.

What does the hardware do in each type of opening?

The type of opening decides which parts window hardware needs and what load it carries. How a window opens affects its weathertightness, ventilation, clear opening and the space it takes up, according to the Ventanas Cortizo guide.

Lift-and-slide doors have their own hardware and their own challenges, which we explain in the guide on large-format minimalist sliding doors and lift-and-slide doors. Here we focus on the sashes that turn on hinges, which depend on the hardware the most.

What do the EN 13126 series tests mean?

EN 13126 is the European series that sets out how window and door-height window hardware is tested; each part covers one type of hardware. According to the scope published by BSI, part 8 specifies the requirements and tests for durability, strength, safety and operation of tilt-and-turn, tilt-first and turn-only hardware, and classifies by durability, mass, corrosion resistance and test sizes.

If the data sheet of the window hardware cites "EN 13126" with nothing more, ask which part it is: the test of a tilt-and-turn set does not apply to a lift-and-slide door.

Test cycles and durability classes

Cycles count the operations the hardware withstands on the test bench. Roto states that class H3 equals 20,000 cycles and H2 equals 10,000, and Siegenia declares 20,000 tilt-and-turn cycles for its Titan AF and ALU 5200 ranges.

To put the figure in context with a calculation of our own: if a sash were opened five times a day every day of the year (1,825 operations a year), 20,000 cycles would last about 11 years. It is an order of magnitude, not a guaranteed service life. As the test is also classified by the mass of the sash, a number of cycles only makes sense next to the weight for which it was obtained.

Corrosion classes

Corrosion resistance is grouped into classes, and 5 is the highest. Interempresas reports that class 5 of EN 1670 requires 480 hours in salt spray, and that a hinge manufacturer reports more than 1,000 hours for its product. Roto and G-U declare class 5 for their hardware; we look at it in more detail in the section on the coast.

What a test class says and what it does not

A class certifies that window hardware was tested in a laboratory under specific conditions. It does not certify the complete window: the behaviour of the window is declared by the system, with its own air, water and wind tests. The full text of the standard is paywalled and we do not reproduce it; the figures in this section come from public descriptions and from manufacturers.

How much weight can a large side-hung sash take?

There is no universal maximum weight: the limit is set by the weakest link between profile, hardware and glass. The data sheets consulted declare between 120 and 160 kg per sash in aluminium systems, and window hardware between 130 and 300 kg depending on the model.

Limits declared by aluminium systems

The data sheet is the first document to read. These are values published by the system manufacturers, always "according to the manufacturer":

Two details. The Cortizo data sheet says to check the maximum weight and dimensions for each type, so the 160 kg is not a value for any sash. And with HD hardware the same series admits taller but narrower sashes, which confirms that the hardware changes the possible size.

What the hardware supports

For aluminium window hardware, as for the rest, the maximum weight is declared by range and by type of hinge. These values are maxima declared by each manufacturer for a specific model. They are not a ranking and they cannot be compared with each other without looking at the conditions:

The weakest-link rule

A profile system rated for 160 kg is no use with 130 kg hardware, and the other way round: 300 kg hardware does not raise the limit of a 120 kg profile. The lowest of the three values applies: profile, hardware and glass. That is why window hardware for a large sash is chosen with the system data sheet in front of you, not the other way round. Dimensions work the same way. For its Aluvision range, Roto states sash heights of up to 3,000 mm without special approval; for greater heights, it is advisable to ask the manufacturer.

Glass weighs more than it seems

Glass is the heaviest part of a large sash. According to the AGC technical data sheet for its Planibel glass, the density of float glass is 2,500 kg/m³, which equals 2.5 kg per square metre and millimetre of thickness. With a calculation of our own: a 1.20 × 2.40 m sash with 6/16/6 double glazing (12 mm of glass) has 2.88 m² and carries about 86 kg of glass alone. The profile and the hardware are added to that figure, and laminated glass or triple glazing raises it.

Hinges, reinforcements and number of support points

When the sash gets close to the limit, window hardware manufacturers offer additional components: Maco adds a load transfer that takes its hardware from 150 to 180 kg, and Siegenia declares 185 kg with a load-transfer cable. Roto, for its part, offers a reinforced hinge (Power Hinge) for heavier sashes.

We have not found a general public rule on how many hinges each weight and format needs. It is defined by the hardware manufacturer for each case: ask for it in writing, with the real weight and size of the sash.

Can you ventilate with the sash closed and protect children?

Yes: window hardware can hold the sash in a ventilation position and limit how far it opens. They are two different functions; here we give the main idea of each.

Ventilation position and micro-ventilation

In a tilt-and-turn window, the tilted position ventilates by opening the sash at the top. The parallel position, on the other hand, moves the sash away from the frame evenly, and it is what micro-ventilation hardware offers. In Winkhaus's activPilot Comfort, that gap is about 6 mm, and the manufacturer states that it protects better than a tilted sash against wind-driven rain, outside noise and insects.

On heat loss, Interempresas reports Winkhaus data: at most 2 °C in 10 minutes with the sash tilted against 0.5 °C in 10 minutes with parallel movement. These are manufacturer figures, not from an independent test.

If ventilation worries you because of damp in the home, our guide on why a house on the Costa del Sol feels cold in winter covers it in more detail.

Opening restrictors and child locks

A restrictor stops the sash from opening further than intended. Siegenia presents a restrictor that keeps the opening below 89 mm, with a version certified to EN 13126-5 for child-safety cases; an adult releases it with a key handle, for example to clean the glass. Part 5 of the series covers, precisely, the devices that restrict the opening of windows and door-height windows.

Burglar resistance is a different matter, with its own classes, and we do not cover it here: our guide on burglar-resistant windows without bars RC2 and RC3.

How does window hardware stand up to coastal salt?

Window hardware defends itself against salt with its coating, and that defence is measured in hours of salt spray and grouped into classes, up to 5, the highest. According to Interempresas, class 5 of EN 1670 requires 480 hours, and one manufacturer reports hinges that exceed 1,000 hours. Roto declares class 5 as the maximum protection in its NX range, and G-U states corrosion class 5 according to EN 13126-8 in its range for 16 mm hardware grooves.

Some manufacturers offer reinforced finishes for demanding environments. Maco describes its Tricoat-Evo as a coating that especially protects hardware in demanding areas of use, such as close to the coast, and Glass Times (2018) reports that it more than doubles the requirements of class 5. That is manufacturer information: if your home is on the seafront, ask which specific finish the hardware on offer has and how many test hours it has.

Maintenance counts too. Kömmerling recommends in its leaflet lubricating the hardware once a year with a suitable product and regularly cleaning the frame and the sash with lukewarm water and neutral soap. As for the frame, the choice between aluminium and PVC on the coast is covered in our guide aluminium or PVC on the coast.

We have not found published data on hardware corrosion measured specifically on the Costa del Sol; all the figures above come from laboratory tests.

What to ask the supplier before choosing window hardware?

Ask for eight data points in writing: that way you check that the window hardware matches what your opening needs and not what is cheapest to fit.

1. Part of the EN 13126 series and class. Which part applies (8 for tilt-and-turn, 16 for lift-and-slide, 17 for tilt-and-slide) and what durability class it has.
2. Maximum sash weight declared by the hardware manufacturer, and the real weight of your project's sash with the glass chosen.
3. Maximum dimensions of sash width and height for that hardware, not only for the profile.
4. Number of cycles tested, together with the weight with which it was obtained.
5. Corrosion class and finish, especially if the home is near the sea.
6. Additional components that a heavy sash requires: reinforced hinges or load transfer.
7. Compatibility with the profile. Standard 16 mm groove window hardware fits several systems: Cortizo states that its COR 70 C16 ST accepts any standard 16 mm groove hardware, but it should be confirmed with the system data sheet.
8. Warranty and documents from the hardware manufacturer. Kömmerling points out that hardware has its own marks and warranty periods, which the window manufacturer must specify.

How we work at Safe Smart Energy

Safe Smart Energy (SSE) is a technical glazing company based in Estepona (Málaga). We design, supply and install windows, sliding doors, glass façades, railings and screens for villas, homes and commercial projects in Marbella, the Costa del Sol and the rest of Spain. We work with Schüco, Reynaers, Cortizo and Aluprof systems.

The system is chosen according to the openings, the orientation of the façade and the expected loads, and window hardware is part of that choice. Project handover includes adjustment of the hardware, a weathertightness check and the technical dossier, with up to 5 years of warranty on installation work. We also offer the activPilot Comfort micro-ventilation hardware and the ChildSafe child lock; you can see the full range of our solutions.