There is a preventive oil which guards metal surfaces from corroding by forming a shield that restricts their contact with moistures and airs such as rust protective oil rust preventer or rust converter.This one is applicable to hand tools such as spanners or wrenches which may be stored under completely dry conditions; other than that another common place would be lubrication on machines used in production lines so as to prevent friction between moving parts leading to their wear out thus causing breakdowns prematurely into such factories .A good example might include weapon parts made out of steel since they do not have any protective covering but need regular maintenance if they are not going to rust within weeks after manufacture while at the same losing their original appearance.