How to distinguish 304 stainless steel?

The main methods to distinguish 304 stainless steel include using stainless steel testing agents, magnetic testing, copper sulphate testing and observing colour changes.

Using stainless steel detection agent: By dropping stainless steel detection agent, different stainless steel products will show different colours. Through the colour change, the authenticity of 304 stainless steel can be identified. This is the more accurate and standard method.

Magnetic test: 304 stainless steel belongs to the austenitic type, which is usually non-magnetic or shows weak magnetism. When using the magnet test, if 304 stainless steel is attracted by the magnet, it means it is not the real 304 stainless steel.

Copper sulphate test: By removing the oxide layer on the steel, drip water on the steel and rub it with copper sulphate. If the steel does not change colour, it can generally be judged as stainless steel. If it becomes purplish red and non-magnetic, it is high manganese steel; those with magnetism are generally ordinary steel or low alloy steel.

Observe the colour change: Use the special testing potion and observe the colour change after dropping on the material. If the colour does not change significantly within a few minutes, but the bottom colour is slightly darker, it means it is 304. If it turns red within 10 seconds, it is not 304.

These methods can help consumers effectively identify the authenticity of 304 stainless steel and ensure the purchase of stainless steel products that meet food-grade standards.