Stainless alloys or stainless steels are steels to which an outer layer of chromium oxide has been applied. To comply with the EN 10088-1 European standard, steel is classified as stainless if it contains at least 10,5% chromium and less than 1,2% carbon in weight.
There are different categories of stainless steels, the most common are:
- X2CrNi18-9 (AISI 304L or A2): used to make everyday products
- X2CrNiMo17-12 (AISI 316L or A4): used in the chemical, pharmaceutical, oil and food industries.
- X8Cr17 (AISI 430): used to made household appliances, sinks…
- X6CrTi12 (AISI 409): used to make automobile exhausts, furnaces…