Technical Bulletin – Corrosion Resistance for Door Closers

Considering whether a door closer meets the necessary corrosion resistance standards can save vital costs in the long run.

Alison Aston, Product Manager for Door Closers at UNION, outlines why this can have such a big impact.

When you are looking for a door closer, you will first want to make sure it works with the size and weight of the door and check if it is certified for use with fire doors.

Those have long been the two main considerations for specifiers and installers alike, and rightly so; a door closer needs to be up to the job and not fall foul of a fire inspection.

But, when looking at the certification of a door closer, how often would you look at the last number in the CE table? This is for corrosion resistance, and it’s potentially rather more important that you may think.

Understanding the corrosion resistance of a door closer is highly important. CE certification gives a grading to how long a door closer can be expected to last, which is stated in 6 grades as defined in EN 1670:

0 – No discernible resistance

1 – Mild resistance (for internal applications with a dry atmosphere)

2 – Moderate resistance (for internal applications where condensation may occur)

3 – High resistance (External applications exposed to occasional rain or dew)

4 – Very high resistance (External applications with severe weather conditions)

5 – Exceptionally high resistance (External, extreme weather conditions)

Considering the corrosion resistance of a door closer is therefore a critical step in specifying the most suitable door closer for the environment in which it is to be installed. If a door closer is needed in a harsh environment – for example, a swimming pool or oil rig – then the potential exposure to salt air demands that a door closer to grade 4 be specified. But this would also be vital for a door closer being fitted to an external door, or to a door accessing (or near to) a kitchen or launderette.

It’s now even more important to check this grading, as some door closers are being made from lower grade metals. This may make them appear to be better value, but their lower expected operating lifespan can result in early replacement – a situation you will doubtless wish to avoid in the future.

As the global leader in door opening solutions, we can help ensure the right door closer is selected. For friendly help and advice, don’t hesitate to contact us at