How to identify the quality of stainless steel plate?

Stainless steel has a large range and many types. Some are non-magnetic, and some are magnetic. It mainly depends on whether the steel contains iron, nickel, and cobalt. If there is, it is magnetic, otherwise it is not. For example, stainless steel knives are magnetic, and some pure decorative materials are not magnetic.

In fact, the degree of corrosion resistance of various stainless steels is different, and they are not absolutely stainless. If what you require is mainly the anti-corrosion function, the commonly used 316L is better, but it cannot be distinguished by magnet attraction. However, corrosion tests such as acid-base and salt spray test methods can be used.