How do you clean stainless steel properly, and what should you avoid?

In metallurgy, the term stainless steel refers to alloyed or unalloyed steels with a particularly high degree of purity. For mirrorINOX, the primary material of relevance is corrosion-resistant stainless steel, which contains at least 10.5% chromium and no more than 1.2% carbon. When exposed to oxygen, the chromium forms a protective passive layer on the surface. We process this material to create decorative and functional finishes. The reactivity of this layer enables it to self-heal after microscopic mechanical damage, provided that no foreign particles impede oxidation. Stainless steel is therefore a durable, recyclable material for demanding B2B applications in interior and exterior environments.

Designations and Synonyms

Stainless steel is identified using various international standards systems, which we strictly apply in our production processes. Precise nomenclature is essential for procurement and design to ensure corrosion resistance and mechanical strength.

V2A and V4A (material grades 1.4301 and 1.4404)

The terms V2A and V4A are historical designations originating from German steel development. Today, V2A generally corresponds to grade 1.4301 and is the standard for general applications. V4A, often designated as 1.4404 or 1.4571, also contains molybdenum. We recommend V4A for environments with increased chloride exposure or in coastal areas. These grades form the basis for our finishing processes, such as electrolytic colouring or polishing to a Perfect Mirror finish.

AISI Classification (American Iron and Steel Institute)

For international projects, we primarily use the AISI system. AISI 304 is the equivalent of European grade 1.4301, while AISI 316L corresponds to grade 1.4404. This 300 series comprises austenitic stainless steels, which we prefer due to their excellent formability and weldability. For our customers, compliance with these standards ensures worldwide comparability and technical certainty when specifying mirrorINOX products.

Inox and Stainless Steel

Inox is derived from the French “inoxydable” and is used internationally as a synonym for stainless steel. In Germany, the term Edelstahl Rostfrei is legally protected by the trademark of Warenzeichenverband Edelstahl Rostfrei e.V. As a specialist finisher in this segment, we ensure compliance with all relevant material standards at our Cleebronn site through our ISO 9001 certification.

Chemical Composition

The performance of the surfaces we finish is based on the precise alloy composition of the base material. The following elements are key to their properties:

• Iron (Fe): The base element makes up the largest proportion of the microstructure.
• Chromium (Cr): A minimum of 10.5% Cr is essential for the formation of the passive layer and for corrosion protection.
• Nickel (Ni): Stabilizes the austenitic microstructure and improves corrosion resistance and workability.
• Molybdenum (Mo): Significantly increases resistance to pitting corrosion in aggressive media in grades such as 1.4404.
• Manganese (Mn): Acts as a deoxidizing agent and increases the strength of the material during production.
• Carbon (C): Is deliberately kept at a low level in corrosion-resistant steels to prevent intergranular corrosion.

Properties

Stainless steel has a specific set of properties that makes it indispensable for high-end architecture and industrial applications. We harness these physical characteristics in our surface treatments.

Mechanical Properties

Stainless steel offers high tensile strength and excellent elongation at break. This ductility enables us to form and deep-draw sheets into complex shapes without damaging the surface texture. Work hardening during the rolling process also creates a robust surface that withstands the demands of public spaces. We supply material that remains mechanically stable while precisely reproducing intricate design textures such as our VIBES rolled textures.

Physical Properties

The thermal conductivity of stainless steel is lower than that of structural steel, while its thermal expansion is higher. We must take this into account when installing large-format façade panels in Cleebronn. Its density is approximately 7.9 kg/dm³, a fixed parameter in the structural calculations for projects. This consistency of physical properties ensures that mirrorINOX products retain their dimensional stability and surface quality even under changing thermal conditions.

Corrosion Resistance

Corrosion resistance is the material’s key characteristic. Its chemically inert passive layer enables stainless steel to withstand moisture and many chemicals. We enhance this protection with our nanoINOX® coatings, which form an additional barrier. However, corrosion resistance depends on surface roughness: the smoother the surface, as with our Perfect Mirror No. 10®, the less opportunity there is for corrosive deposits and contaminants to adhere.

Magnetism

Austenitic stainless steels such as 1.4301 are non-magnetic in the solution-annealed condition. However, cold forming, such as bending or rolling, can cause deformation-induced martensite to form locally, resulting in slight residual magnetism that is technically harmless. This property is relevant for specialised applications in medical technology or research. We provide detailed advice on the magnetic susceptibility of our various grades and finishes to prevent malfunctions in sensitive environments.

Applications and industries

We manufacture stainless steel solutions for a wide range of demanding industries where hygiene and aesthetics converge.

• Architecture and façade construction: Use of large-format, coloured panels with nanoINOX® coating for durable building envelopes.
• Elevator construction: Durable, decorative wall cladding with anti-fingerprint properties that minimizes cleaning requirements.
• Food and pharmaceutical industries: High-gloss polished surfaces for sterile processes and easy cleaning in compliance with strict hygiene standards.
• Yacht and shipbuilding: Use of highly corrosion-resistant 1.4404 for exclusive exterior components in marine applications.
• Retail and interior fit-outs: Design of prestigious counters and cladding with custom textures such as VIBES or BEADS.

Overview of international standard designations

To ensure worldwide availability and interchangeability, we specify our materials according to various international standards:

• EN 10088-2: The European standard for corrosion-resistant steel products for construction.
• ASTM A240: The US standard for stainless steel plate, sheet and strip for pressure vessels and general applications.
• JIS G4305: Japanese Industrial Standard for cold-rolled stainless steel sheet, relevant to the Asian market.
• ISO 15510: International standard that harmonizes the chemical composition of stainless steels worldwide.

Refining stainless steel – What mirrorINOX makes of it

At our production facility in Cleebronn, we have been finishing stainless steel to create high-end surfaces since 2016. We produce mirror-polished finishes such as Perfect Mirror No. 10®, which is regarded as the industry benchmark for reflection quality. One particular focus is the nanoINOX® process. This is a sol-gel-based coating that we apply in a wide range of colours. The coating significantly improves cleanability: the nanoINOX® AFP/ETC (AntiFingerPrint / Easy-To-Clean) process reduces the visibility of fingerprints and saves resources during maintenance.

With regard to cleaning, we have tested various methods for compatibility with our surfaces. The following guidelines apply to mirrorINOX finishes:
We consider cleaning with warm water and compressed air to be ideal. A mild soap solution is also safe for our products. Unsuitable household remedies such as vinegar, baking powder or baking soda, however, must be strictly avoided. Acids (such as citric acid) must likewise never be used on coloured, PVD/TiN or nanoINOX®-coated surfaces, as they can chemically attack and irreversibly damage the functional thin-film coatings and colour pigments. Chloride-free glass cleaners may only be used with caution and after prior testing on an inconspicuous area. We deliver consistent quality and, to preserve the value of the surfaces, recommend only professional maintenance cycles without abrasive cleaning aids.