Stainless steel comes in different grades, usually designated by their chromium-to-nickle ratio. A stainless steel ratio of 18/8 means 18% chromium and 8% nickel content. The higher the percentage of these elements, the better the stainless steel grade. High quality 18/10 stainless steel gives a high level of stain, corrosion and rust resistance. Low quality sinks can be identified by holding a magnet against them. High quality stainless steel will stick to a magnet, lower quality steel won't.