Crude oil is an energy resource that mostly composed with hydrocarbons and trace corrosive compounds as well found some cruxes in the petroleum refining industry because of the vast applications of the different types of metals. There were expected to investigate the effect of two different types of crude oils on the corrosion of seven types of selected ferrous metals in the pertinent research. The concerned corrosive properties of both crude oils were tested by standard methods and instruments also the chemical compositions of selected ferrous metals were tested. The corrosion rates of a series of similar size prepared metal coupons were tested after limited immersion time periods as three trials in crude oils by the weight loss method since aiding the microscopic analysis to identify the corrosion compounds. Apart from those speculations the decayed metallic elemental mounts from the metals into crude oils and the reductions of the initial hardness of metal coupons were tested. The obligatory results showed the relatively higher corrosion rates from carbon steels, relatively lower corrosion rates from stainless steels in both crude oils, formation of FeS in most of observations, decay of ferrous and copper into crude oils from some metals and slight reductions of the initial hardness of metal coupons due to the formation of the corrosion on the metal surfaces.