In metallurgy, stainless steel is defined as a steel alloy with a minimum of 11% chromium content. Stainless steel does not stain, corrode, or rust as easily as ordinary steel (it stains less), but it is not stain-proof. There are different grades and surface finishes of stainless steel to suit the environment to which the material will be subjected in its lifetime. Stainless steel is 100% recyclable and is available in different forms.