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Granite® HDXtreme offers three-layer coating system for maritime-level protection

ArcelorMittal Europe – Flat Products has released Granite® HDXtreme, the latest pre-painted steel in our organic coated Granite® range. Granite® HDXtreme is uniquely beautiful, resilient against corrosion, sustainable, and can be used in both indoor and outdoor applications. The three-layer coating system is made of polyurethane and includes a primer, basecoat, and varnish. Together they enable ArcelorMittal to guarantee the steel’s performance, even on facades and roofs which are close to the sea. Granite® HDXtreme comes in a huge palette of colours and three different finishes to make any project unique.

The strength of Granite® HDXtreme comes from its three-layer coating system which ranges from 70 to 75 microns (µm) depending on the finish. Each layer performs a different but integral function.

The primer layer plays a key role in corrosion protection by ensuring the top coat adheres tightly to the underlying steel. On top of that is a polyurethane basecoat which ensures the steel’s durability. It also provides the final colour. The coating is finished with a layer of varnish which adds texture to the coating, increases durability and surface robustness, and enhances the UV weathering potential of Granite® HDXtreme.

The three-layer protection system of Granite® HDXtreme enables ArcelorMittal to offer long guarantees 

Weathering resistance

Granite® HDXtreme already meets the requirements of the updated EN 10169 standard for continuously organic coated flat steels. We expect that Granite® HDXtreme will be rated RUV5 when the new standard is published later in 2021. RUV5 indicates the coating has the highest possible resistance to UV light.
We have also evaluated the coating by exposing pre-painted samples of Granite® HDXtreme to accelerated UV, humidity, and temperature variations for up to 4,000 hours. Natural outdoor exposure tests have also been carried out at locations around the world.

Granite® HDXtreme meets the new EN10169 standard for continuously organic coated flat steel

Automatic guarantees

ArcelorMittal’s extensive experience and testing enables us to offer a full guarantee on Granite® HDXtreme, even in highly corrosive seafront locations. The guarantee covers non-perforation of the sheet metal and non-delamination of the paint film.
The guarantee is automatically granted for all building projects using Granite® HDXtreme, without prior agreement or a questionnaire. It is applicable to both roofing and facades and also covers the installation of photovoltaic (PV) modules on a roof.

Long guarantees are available for Granite® HDXtreme, even in marine environments 

Samples of the Granite® HDXtreme are already available from your ArcelorMittal customer support team. By end of March 2021, they will also be available through our online sample shop.

Related links

More info on Granite® HDXtreme
More info on Granite® range
Visit our Building page
Contact ArcelorMittal Europe – Flat Products
Order your Granite® sample here


Copyright banner: Jeroen Op de Beeck and Philippe Vandenameele