Despite Arizona’s mostly dry desert climate, materials still rust like they do in the wetter and more humid regions elsewhere. Karl Sieradzki, a Fulton Schools professor of materials science and engineering, explains that iron and its alloys, like steel, still oxidize in desert climates. The difference is they do so considerably more slowly in places with low moisture — such as the desert Southwest. But a stainless-steel tool coated in a thin layer of chromium can remain rust-free.