What is stainless steel?

The European normative UNE-EN 10088, defines stainless steel as the iron alloy bearing ≥10.5% chromium and ≤1.2% carbon, necessary to ensure the build-up of a self-healing surface layer (passive layer) which provides the corrosion resistance.

Acero Inoxidable

Stainless Steel Grades

Stainless Steel is an alloy made of iron, chromium and carbon. Occasionally it has other complementing elements, the most common one is nickel.

Chromium is what gives this material its stainless nature. In oxidising atmospheres, for example air, chromium makes a very dense and thin oxide layer which isolates the material from any corrosive action.

The passive layer should always be maintained undamaged, this guaranties stainless steel high corrosion resistance

Stainless Steels are classified depending on their different containing elements and also on the quantity of each of these elements into their composition.

Generally, four basic families are considered: martensitic, ferritic, austenitic and duplex stainless steels.

Information courtesy of ACERINOX

Stainless Steel Product Range

The stainless steel range of products is defined according to its fabrication process. The mechanical and geometrical properties of materials with a similar routing are alike.


made of stainless steel manufactured by Acerinox


made of stainless steel manufactured by ROLDAN


made of stainless steel manufactured by INOXFIL



1D | Nº1

Hot rolled, annealed and pickled

2D | 2D

Cold rolled, annealed and pickled

2B | 2B

Cold rolled, annealed, pickled and wet skin-passed

2R | BA

Cold rolled, bright annealed and dry skin-passed

2G | Nº4

Grinding: brushed or dull polished

2M | Emboss

BA finish material. Roll-embossed


The condition of the surface of any stainless steel is vital not only for aesthetic purposes, but it has a self-healing surface layer (passive layer) and wears no coatings.  The selection of the appropriate finish for a particular application is decisive for a good behavior results with almost no maintenance during its life cycle.

This is a short list of the most common finishes produced by Acerinox, our main associated and Spanish stainless steel manufacturer.  Regarding stainless steel finishes normative, we would like to point out that the finish of a surface is determined by its manufacturing process and not, with a few exceptions, by its roughness. For more information, we suggest to see EN 10088-2:2014.