At present, there are many kinds of stainless steel pellets in the world, including sus304, sus202, sus430, sus4 10 and so on. What's more, iron wire balls are sold as stainless steel balls or stainless steel iron balls. How to distinguish stainless steel balls from stainless steel iron balls is a disadvantage for users without laboratory equipment. In fact, there is a relatively simple but practical method, which is to directly soak stainless steel balls or stainless steel iron balls in water. If the chromium content reaches above 13 and the nickel content reaches 8- 10, the pellets will certainly not rust after 24 hours.