What makes stainless steel the ideal choice for façades?

A stainless steel façade is the external cladding of a building made from corrosion-resistant steel alloys. These are primarily used in the form of sheets, composite panels, panels or profiles. Essentially, stainless steel is an alloy containing at least 10.5% chromium, which forms a protective passive layer on the surface. mirrorINOX transforms these base materials into design-oriented finishes that provide durable weather protection for both new-build and refurbishment projects. The façade is generally designed as a ventilated rainscreen system, enabling efficient thermal separation and ventilation of the building fabric.

Terms and synonyms for façade stainless steel

Correct material specification is crucial to the durability of a façade. The construction industry uses various classifications, which we distinguish precisely for our customers.

V2A – The Standard Material

The designation V2A (test melt 2 austenite) is a historical term now generally used synonymously with material grade 1.4301 or AISI 304. We recommend this grade for façades in environments with low levels of pollution. It offers good corrosion resistance and is ideally suited to grinding or polishing.

V4A – For More Demanding Requirements

V4A (material number 1.4404/1.4571 or AISI 316/316Ti) also contains molybdenum. We prefer to use this material for façade projects near the coast or in areas exposed to industrial pollution. The addition of molybdenum significantly increases resistance to chloride-induced pitting corrosion.

Inox and Stainless Steel

Internationally, the terms “Inox” (from the French inoxydable) and “Stainless Steel” have become established. In mirrorINOX technical documentation, we primarily use the precise EN standard designations to prevent confusion in international tenders and ensure the exact reproducibility of the surface finish.

Chemical Composition of Stainless Steel for Façades

The performance of a stainless steel façade is determined by its precise alloy composition. We process materials containing the following principal alloying elements:

• Iron (Fe): The base alloy and main component of the steel.
• Chromium (Cr): Content of 17.0% to 19.5%; responsible for forming the protective passive layer.
• Nickel (Ni): Content from 8.0% to 10.5%; stabilizes the austenitic microstructure and improves formability.
• Molybdenum (Mo): Approx. 2.0% to 2.5% in V4A grades; significantly increases chloride resistance.
• Manganese (Mn): Improves strength and hot formability during sheet production.
• Carbon (C): Very low content (< 0.07%) to prevent intergranular corrosion during welding.

Properties of Stainless Steel for Façade Construction

Stainless steel combines physical and mechanical advantages that make it superior to aluminium or organically coated sheet steel.

Mechanical Properties

Stainless steel façade sheets are characterised by high tensile strength (500 to 700 N/mm²) and a high yield strength. We manufacture panels that offer high rigidity despite their low material thickness. This enables the production of large-format cassettes with minimised dead weight, reducing the structural load on the substructure and accelerating installation.

Physical Properties

The coefficient of thermal expansion of austenitic stainless steel is approximately 16.0 x 10⁻⁶ K⁻¹. We take this into account when designing expansion joints in façade systems. Stainless steel also has comparatively low thermal conductivity, which supports the thermal separation of the building envelope and contributes to the building’s energy efficiency.

Corrosion Resistance

Corrosion resistance is the material’s core strength. Upon contact with oxygen, a passive chromium oxide layer forms spontaneously. Where required, we enhance this protection with our nanoINOX® coating, which also provides anti-fingerprint (AFP) and easy-to-clean (ETC) properties. This provides lasting protection for the façade against acid rain and industrial emissions.

Magnetism

The grades used by mirrorINOX for façades (1.4301, 1.4404) are austenitic in the solution-annealed condition and therefore non-magnetic. This is relevant for specific technical applications or design requirements where magnetic interference must be avoided or a homogeneous microstructure is required for surface finishing.

Applications and Industries

Thanks to their versatility, stainless steel façades are used in a wide range of construction sectors.

• Commercial and office architecture: We supply mirror-polished or PVD-coated sheets for prestigious corporate headquarters, such as the RMK headquarters in Yekaterinburg.
• Residential construction: Used as durable façade panels, for example on the BUWOG building in Vienna, to minimize maintenance costs.
• Public buildings: Airports, railway stations and museums use stainless steel for its resistance to vandalism and ease of cleaning.
• Industrial construction: Used in corrosive environments where conventional coatings would fail.
• Infrastructure projects: Noise barriers and ceiling cladding in tunnel construction benefit from the material’s Class A1 fire resistance.

Overview of international standard designations

For the global export of our finished sheet metal from Cleebronn, we use the established international standards cross-references:

• Europe (EN 10088): 1.4301 (X5CrNi18-10) and 1.4404 (X2CrNiMo17-12-2).
• USA (ASTM/AISI): AISI 304 and AISI 316L.
• Japan (JIS): SUS 304 and SUS 316L.
• China (GB): 06Cr19Ni10 and 022Cr17Ni12Mo2.
• Russia (GOST): 08X18H10 and 03X17H14M2.

Stainless Steel Finishing – mirrorINOX Expertise

We transform raw stainless steel sheets into striking façade elements. At our production facility in Cleebronn, we use state-of-the-art equipment that guarantees exact reproducibility of the finishes—a critical factor for large-scale projects involving multiple construction phases. We manufacture proprietary products such as Perfect Mirror No. 10® for maximum reflectivity, as well as pattern-rolled finishes for textured effects. ISO 9001 certification ensures consistently high quality standards. Our nanoINOX® coatings can be applied in an almost unlimited range of colours, giving stainless steel façades a colour palette that was previously achievable only with paint, but with significantly greater UV resistance.