Generally speaking, the most direct way to identify the materials of 201 and 304 is through a special potion. We only need to drop the potion onto the stainless steel mesh for about 1 minute. If the potion is red, then It means that it is a stainless steel mesh of 201 material. If it does not change color when dropped on it, it means that it is a stainless steel mesh of 304 material.
If there is no way to buy a special test potion in some places, we can send the
stainless steel mesh to the local quality and technical supervision bureau for testing.