According to the study of material physics, the magnetic properties of the metal are derived from the structure of the electron spin, and the electron spin belongs to the quantum mechanical properties, either "up" or "down". In ferromagnetic metals, electrons are automatically rotated in the same direction, and some of the antiferromagnetic metal materials are in the regular pattern, while the adjacent electrons move in opposite directions or antiparallel spin, but for triangular crystals In the case of electrons, since the two electrons in each triangle must spin in the same direction, the spin structure is no longer present.
In general, austenitic stainless steel (represented by 304) is non-magnetic, but may also be weakly magnetic, and ferrite (mainly 430, 409L, 439 and 445NF, etc.) and martensite As a representative) are generally with a magnetic.
Stainless steel which has some steel (such as 304, etc.) classified as "non-magnetic stainless steel" refers to its magnetic indicators below a certain value only, that is, generally stainless steel are more or less with a certain magnetic.