What does Inox mean and how is the term used?

Inox is derived from the French term “inoxydable”, which simply means “stainless”. Technically, it is a collective term for a group of steels with exceptional resistance to corrosion and acids. The development of these alloys began over 100 years ago. Today, the term Inox encompasses a wide range of chromium-nickel steels whose specific proportions of alloying elements such as chromium, titanium or molybdenum provide particular mechanical advantages. More than 100 different grades of stainless steel are currently available to meet a wide variety of application requirements.

Designations and Synonyms – Relevant Standards and Names

In international trade and technical documentation, numerous terms are often used synonymously with Inox. We explain the most important designations to avoid misunderstandings in specifications.

V2A and V4A

These designations are historical abbreviations derived from “Versuchsschmelze 2 Austenit” (test melt 2 austenite). V2A (often grade 1.4301) is the classic standard stainless steel for interior applications and moderate outdoor conditions. V4A (often 1.4404 or 1.4571) also contains molybdenum, making the material more resistant to chlorides. We particularly recommend V4A for marine projects or swimming pools.

AISI and ASTM

The American Iron and Steel Institute (AISI) uses a three-digit numbering system. For example, grade AISI 304 corresponds to the European grade 1.4301, while AISI 316L is assigned material number 1.4404. These designations are essential for our international projects in the USA or Asia, as we must ensure that the chemical composition complies with local standards.

Nirosta and chrome steel

Nirosta is a protected trade name that has nevertheless become established in common usage as a synonym for Inox. Chrome steel, by contrast, is often incorrectly used as a generic term, although technically it refers more specifically to ferritic steels with no significant nickel content. At mirrorINOX, we distinguish precisely between these grades, as their polishing characteristics and weldability differ significantly.

Chemical Composition of Inox

The properties of stainless steel depend directly on its chemical composition. The alloying elements determine whether the steel is magnetic, how readily it can be formed and how reliably the passive layer regenerates.

• Chromium (Cr): The most important constituent, with a minimum content of 10.5%. Chromium enables the formation of the protective passive layer.
• Nickel (Ni): Stabilizes the austenitic microstructure and improves corrosion resistance and formability.
• Molybdenum (Mo): Increases resistance to pitting corrosion, particularly in chloride-containing environments.
• Titanium (Ti): Provides stabilization against intergranular corrosion, particularly in welded components.
• Carbon (C): Is deliberately kept at a low level in stainless steels to avoid adversely affecting corrosion resistance (L grades).

Properties of stainless steels

Stainless steel has a unique set of properties that sets it apart from aluminium or conventional structural steel. We use these physical characteristics to create surface solutions that last for decades.

Mechanical Properties

Inox steels tend to work-harden and have high tensile strength. They are ideally suited to forming processes such as press braking, bending and deep drawing. Despite its high hardness, the material remains tough, making it ideal for safety-critical components in elevator construction and materials handling systems.

Physical Properties

One key aspect is its lower thermal conductivity compared with copper or aluminium. Stainless steel also has excellent polishing properties. We harness this characteristic in our Perfect Mirror No. 10® to achieve reflectivity levels equal to those of glass mirrors, while offering shatter resistance and durability.

Corrosion Resistance

The formation of a dense oxide layer (passive layer) protects stainless steel from environmental influences. This layer is self-healing: if mechanically damaged, it reforms when exposed to oxygen. Where required, we enhance this protection with our nanoINOX® coating, which provides additional barrier properties against aggressive media.

Magnetism

Whether stainless steel is magnetic depends on its microstructure. Austenitic steels (such as 1.4301) are non-magnetic in the annealed condition. Ferritic steels, by contrast, are ferromagnetic. At mirrorINOX, we provide expert advice if your project has specific requirements for magnetic shielding or detectability.

Applications and Industries

Thanks to its hygienic properties and durability, stainless steel is used in virtually all high-end sectors. We supply customers worldwide with refined surfaces for a wide range of applications.

• Architecture and façade construction: Used as a durable building envelope, with coloured PVD coatings adding distinctive aesthetic accents.
• Elevator and escalator construction: Use of textured sheet metal for scratch-resistant, visually appealing cabin walls.
• Yacht and shipbuilding: Mirror-polished surfaces in V4A grade for maximum corrosion resistance to salt water.
• Medical and pharmaceutical technology: Use of non-porous surfaces to meet the strictest hygiene requirements and sterilization processes.
• Plant and tank construction: Fabrication of Inox for chemically resistant tanks in the food and chemical industries.
• Aerospace: High strength combined with low maintenance requirements for aircraft cabin interior components.

Overview of international standard designations

To ensure comparability, we list the most common materials according to various standards systems here. This simplifies specification for global supply chains.

• Material No. 1.4301: Equivalent to AISI 304 / X5CrNi18-10. The standard austenitic grade for general applications.
• Material No. 1.4404: Equivalent to AISI 316L / X2CrNiMo17-12-2. The acid-resistant grade for demanding environments.
• Material No. 1.4016: Equivalent to AISI 430 / X6Cr17. A ferritic stainless steel often used for decorative interior applications.
• Material No. 1.4571: Equivalent to AISI 316Ti. Titanium-stabilized stainless steel for demanding high-temperature and corrosive environments.

Finishing stainless steel – precision from mirrorINOX at its Cleebronn facility

Since our founding in 2016, we have been producing stainless steel surfaces to the highest technical standards at our Cleebronn facility. mirrorINOX is not merely a distributor, but a manufacturer with in-depth expertise in mechanical and chemical surface treatment. We finish stainless steel sheets by mirror polishing (Perfect Mirror No. 10®), grinding and glass bead blasting (BEADS).

A unique feature is our PVD/TiN coating system, which allows us to add colour to Inox in a controlled process without losing its metallic feel. With our proprietary nanoINOX® brand, we also offer coatings with anti-fingerprint properties (AFP) and an easy-to-clean effect (ETC). Our ISO 9001-certified processes guarantee complete reproducibility of the finishes – a crucial factor for large-scale façade projects, where every sheet must have exactly the same appearance.