Neodymium iron boron magnets identify whether the quality of stainless steel is reliable

In daily life, we often come into contact with stainless steel products, such as stainless steel pipe, stainless steel faucets and so on. Stainless steel is not easy to rust and is widely used. Some friends will use neodymium iron boron magnets to identify the quality of stainless steel. Is this approach reliable?
First of all, stainless steel is divided into types due to different materials, such as ferritic stainless steel, 304 steel, 204 steel and so on.
Secondly, the NdFeB magnets can only attract ferritic stainless steel. Ferritic stainless steel generally refers to an iron-based alloy with a chromium content of 11% to 30% and a crystal structure of a body-centered cubic lattice. In addition to some chromium elements, other alloying elements, such as molybdenum, aluminum, and titanium, are added to form and stabilize the ferrite structure. The carbon content of ferritic stainless steel is relatively low, less than or equal to 0.12, but the carbon content of cast ferritic stainless steel ZGCr28 is relatively high, reaching 0.05% to 1.00%. 304 steel will also have magnetism, whether it is magnetism or not can not judge the quality of stainless steel.
Finally, people often think that neodymium iron boron magnets absorb stainless steel materials to verify their pros and cons and their authenticity. They are not attractive and non-magnetic. They are considered good and genuine; if they are magnetic, they are considered fake. In fact, this is an extremely one-sided and impractical method of identifying errors.