I've got what may be a basic question but I need to know more because I have a few power cords I've removed from non working units and some of the AC plugs (the parts that make contact with the wall outlet) look silver as opposed to the yellowish color of brass. Magnets do not stick to them so they are obviously non ferrous but what are the metals used if not brass? Aluminum perhaps? I'm trying to separate metals into containers so I know exactly what they are and when a project comes along requiring a certain metal I'll know which container to draw from for any given project. Any input would be greatly appreciated!