Ferritic stainless steels are essentially chromium containing steel alloys with at least 10.5% Cr. They can be grouped based on their chromium content: low chromium (10.5 to 12.0%), medium chromium (16 to 19%), and high chromium (greater than 25%). This article provides general information on the metallurgy of ferritic stainless steels. It describes the two types of heat treatments- annealing and stress relieving, which are used to avoid sensitization and embrittlement. The article also provides information on casting and stabilization of ferritic stainless steels to avoid precipitation of grain boundary carbides.