Peculiar smell, which we used to call "metallic" occurs due to contact of the skin with metal. Everyone is familiar rather unpleasant smell that comes from the small coins made of copper, brass or iron. In fact, it's the smell of sweat, rather than metal evaporation.
Scientists have conducted a series of experiments studying the chemical reactions that occur during hand contact with iron, steel and cast iron. They were able to "catch" the evaporation of the skin of hands of second-hand metal object person and analyze their chemical composition by chromatography (ie, the method of separating mixtures based on differences in the speed of their movement).
It was found that so-called "odor metal" occurs when contained in human sweat acid chemically react with the carbon and phosphor patches, which are a part of metals. As a result, aldehydes and ketones having the same characteristic and rather strong smell.