Oops! It is ferrous but magnets don’t stick to stainless.
“Oops! It is ferrous but magnets don’t stick to stainless.”
Ferritic stainless steels - these steels are magnetic primarily due to the presence of ferrite, a compound of iron and other elements. The crystals of ferrite and iron make this type of stainless steel magnetic. It is also important to note that some stainless steels with ferrite have a weak magnetic pull.
Stainless steel grades 409, 430, and 439 are also known as ferritic stainless steels.
Martensitic stainless steels - this category has many types of stainless steel that are magnetic. It is possible for martensitic stainless steel to have a ferromagnetic crystal structure if iron is present. The magnetism of martensitic steel is due to iron being the main component. Martensitic stainless steel has carbon trapped in its crystals are can be hardened to become extremely strong but have reduced chemical resistance compared to austenitic stainless steels.
There are three grades of martensitic stainless steel - 410, 420, and 440.
https://www.eclipsemagnetics.com/resources/are-all-stainless-steels-magnetic/