Someone always judge the authenticity of stainless steel by magnetism. They thought if the material can be sucked by the magnetic-iron, it colud not be stainless steel, at least, it colud not be good stainless steel material. Actually, it's nothing about magnetism, the only way to judge them is to analysis the chemical elements.
We know that 304 stainless steel belongs to the austenite type, but the austenite is no magnetic or weak magnetic, so people will think that the good stainless steel is no magnetic. However, we ignored that the smelting process or some other processing can caused magnetism while its chemical composition fluctuation , it can not be considered to be counterfeit or substandard products. In addition, after cold working, the organizational structure of or processing will be transformed to martensite, the greater the degree of cold deformation, the more martensite transformed and the magnetism is bigger. On the contrary, the 200 series of stainless steel, which has lower quality, is very likely not to be magnetic.
In particular, it is suggested that the magnetism of the 304 stainless steel caused by these reasons is not the same level as that of the other materials, that is to say, the magnetism of the 304 steel always shows the weak magnetism. This tells us that if the stainless steel strip is weakly magnetic or completely magnetic, it may be 304 or 316 material. If the magnetism is the same as carbon steel, it is probably not 304 material.
If we need to identify the material clearly, we can further test it by stainless steel calibration medicine, chemical experiment analysis, spectrum detection and analysis. Among them, chemical experiment analysis and spectral detection analysis can identify the content of each element accurately, and it is the most effective method to identify the material.