1. What steel is stainless steel? Stainless steel is a type of steel, steel that contains carbon (C) was below 2% called the steel, is greater than 2%. The addition of chromium in iron steel smelting process (Cr), nickel (Ni), manganese (Mn), silicon (Si), titanium (Ti), molybdenum (Mo) and other alloying elements improved the performance of the steel steel with corrosion (i.e. not rust) that we often say that the stainless steel. 2, why there are different grades of stainless steel? Stainless steel in the smelting process, due to the addition of alloying elements in different varieties of different varieties, adding different quantities. Its characteristics are different, in order to distinguish between the different grades of crown, the following are common decorative stainless steel "different alloy elements" content is for reference only: grade of steel (C) (Si) (Mn) (P) (S) (Cr) (Ni) (Mo) (Cu) 304 ≤ 0.08 ...