The time it takes for steel to rust is primarily dependent on its exposure to air and water. This exposure can be reduced with the application of protective coatings. Steel rusts more quickly in salt water than in fresh water.
Certain types of steel rust more slowly due to their additives, such as zinc in galvanized steel, chromium in stainless steel and aluminum-silicon alloy in aluminum steel. Rust is best prevented by storing metal tools in cool, dry containers and painting exposed metal surfaces with paint that contains oil or acrylics. Regular cleaning is also advised, as dirt attracts moisture.