There was a fun event in the universe today. In a couple of materials. A student of the 70s told how when buying household appliances (noise, fork, etc.) to determine stainless steel it or not. The dialogue is as follows:... Go to the seller and ask for a certificate of the product. If you see that the chromium content is less than 13%, then with a wild whisper, tick it in the side of the fork and say that it is not stainless steel.