What distinguishes ground stainless steel sheets, and what grinding patterns are available?

What are ground stainless steel sheets?

Ground stainless steel sheets are produced by mechanically processing the surface with abrasives. In this machining process, rotating abrasive belts or brushes remove material to create a defined texture. We primarily distinguish between longitudinal, transverse and cross grinding. The process is not purely aesthetic but also serves technical purposes: we reduce surface roughness (Ra value), remove rolling defects and prepare the material for further finishing steps, such as our nanoINOX® coating. The choice of abrasive and grit size determines the final appearance, from matt to satin gloss.

Designations and synonyms

Stainless steel sheets are identified using various standards systems that classify both the chemical grade and the surface finish. For purchasers and design engineers, precise nomenclature is essential to ensure batch-to-batch reproducibility.

Material numbers and abbreviated designations according to DIN EN 10088

The most common designation in Europe is the material number (WNr.). The classic grade 1.4301 (X5CrNi18-10) is known as V2A, while the molybdenum-containing grade 1.4404 (X2CrNiMo17-12-2) is referred to as V4A. This standard precisely defines the alloying element content that determines corrosion resistance and processability. We process these grades as standard on our grinding lines.

AISI and ASTM Standards

In international project business, we frequently encounter the designations of the American Iron and Steel Institute (AISI). AISI 304 is largely equivalent to the German grade 1.4301, while AISI 316L corresponds to 1.4404. These equivalent designations are particularly relevant in specifications for equipment manufacturing and the pharmaceutical industry, as they ensure global comparability.

Surface Finish According to Standards

DIN EN 10088-2 defines ground finishes with the designation "2G" and brushed finishes with "2J". We supplement these designations with specific grit sizes such as K240 or K320. At mirrorINOX, we go beyond these standards and define proprietary finishes such as SATIN to offer our customers more precisely specified appearances than the general standard allows.

Chemical Composition

The performance of the ground-finish sheets is determined by the alloy composition of the base material. Here we list the proportions for the most commonly used grades:

• Chromium (Cr): 17.0–19.5% (forms the protective passive layer)
• Nickel (Ni): 8.0–10.5% (stabilizes the austenitic microstructure)
• Molybdenum (Mo): 2.0–2.5% (V4A/1.4404 only, increases resistance to chlorides)
• Carbon (C): max. 0.07% (lower levels improve weldability)
• Manganese (Mn): max. 2.0% (contributes to strength)
• Silicon (Si): max. 1.0% (used for deoxidation)

Properties of ground stainless steel sheets

Grinding modifies the mechanical and physical properties while preserving the steel’s basic microstructure. We examine the four critical areas for industrial applications.

Mechanical Properties

Ground sheets have a tensile strength of approx. 500 to 700 N/mm². The grinding process causes minimal work hardening at the surface. The 0.2% proof stress (Rp0.2) is typically at least 200 N/mm². These values ensure excellent formability, allowing us to supply the sheets for complex enclosure geometries or façade elements.

Physical Properties

Stainless steel has a density of approx. 7.9 kg/dm³. Its thermal conductivity is lower than that of structural steel, which must be taken into account during welding. The coefficient of thermal expansion is approx. 16 x 10⁻⁶ K⁻¹, making expansion joints necessary, particularly for large-area exterior façade cladding.

Corrosion Resistance

Corrosion resistance results from the formation of a passive layer. Grinding increases the effective surface area. Maintaining low Ra values is therefore essential: the smoother the finish (e.g. Ra < 0.4 µm), the less surface area is exposed to pitting or deposits. We measure these values immediately after production to ensure durability in aggressive environments.

Magnetism

The grades we process most frequently (1.4301, 1.4404) are austenitic and non-magnetic in the solution-annealed condition. Cold forming or intensive grinding may result in slight residual magnetism (delta ferrite). For applications requiring complete non-magnetism, we can advise you on the selection of specific grades or post-treatment processes.

Applications and Industries

Ground stainless steel sheets are used in almost all B2B sectors due to their hygienic and aesthetic benefits. We provide tailored solutions for the following areas:

• Architecture and façade construction: We manufacture panels for wall and ceiling cladding as well as prestigious entrance areas.
• Elevator construction: Our stainless steel sheets provide robust, visually appealing cladding for cabin walls and control panels.
• Food industry: We supply sheet metal with specified Ra values for work surfaces, containers and processing equipment.
• Pharmaceutical engineering: We produce surfaces with extremely low roughness to ensure cleanability and sterility.
• Mechanical engineering: We finish housing components and protective covers that provide both mechanical protection and an attractive appearance.
• Home appliance industry: We supply material for the fronts of ovens, refrigerators and extractor hoods.

Overview of international standard designations

To support global sourcing, we list the relevant standards for ground finishes:

• Europe: EN 10088-2, finish 2G (ground) or 2J (brushed)
• USA: ASTM A480, No. 3 (coarse finish) or No. 4 (general-purpose finish)
• Japan: JIS G4305, No. 4 finish
• International: ISO 9445 for tolerances on cold-rolled wide strip

Stainless steel finishing – mirrorINOX expertise

Since our founding in 2016 at our Cleebronn site, we have specialized in high-end finishing of stainless steel sheets. We manufacture using state-of-the-art grinding systems, some of which we developed in-house, ensuring exceptional reproducibility.

Our proprietary brands set market standards: Under the SATIN name, we offer finishes ranging from K100 (SATIN 1) to ultra-fine K600 (SATIN 10). For a high-contrast appearance, we offer HAIRLINE finishes distinguished by long, continuous grinding lines. Where technical requirements such as slip resistance are paramount, our CROSS process (cross-grinding) is used.

We also combine ground finishes with other processes. We apply PVD/TiN coatings to create coloured accents or use our nanoINOX® technology to provide anti-fingerprint properties. In addition to stainless steel, we also finish aluminium, brass and bronze. Our quality management system is certified to ISO 9001, providing customers throughout Germany and internationally with reliable processes. We supply sheets in dimensions and thicknesses precisely tailored to the requirements of vessel construction or architecture.