With an 18% content of chromium, the 304 forms a protective chromium oxide layer. This layer is passive and non-reactive and seals and protects the iron below it from external influences. When scratched or damaged the oxide layer is able to “heal” itself providing there is enough oxygen available. This process of renewal makes stainless steel resistant to rusting compared to regular steel. The 8% nickel enhances the overall corrosion resistance and contributes to the formability as well as its polished and bright appearance.