Whether stainless steel square lunch boxes are better, magnetic or non-magnetic, and whether 18-0 or 18-8 is better.

Non-magnetic is better. Non-magnetic is stainless steel that will never rust. If it is magnetic, it is made of "stainless iron" as the saying goes, and it is easily corroded and rusted. 18-0 is the Cr18 series, which represents the Cr content of 18, does not contain nickel (Ni), and is a magnetically conductive stainless steel that is easily corroded. 18-8 refers to the Cr18Ni8 series, which represents a Cr content of 18 and a Ni content of 8. This type is austenitic stainless steel. So 18-8 is better, it won’t rust, but it’s more expensive. (Stainless steel tableware generally contains chromium and nickel. Chromium is a material that makes products rust-free, while nickel is a corrosion-resistant material. Stainless steel tableware often has "13-0", "18-0", and "18-8" There are three types of codes. The number in front of the code indicates the chromium content, and the number after it indicates the nickel content.)