A metal bar is a long, solid piece of metal that can be used for a variety of purposes. An INGOT is a type of metal bar that is usually cast from molten metal and cooled to form a block or bar shape. A RAIL is a metal bar that is used in the construction of railway tracks. Lastly, a ROD is a metal bar that is typically cylindrical in shape and is used for a variety of applications such as reinforcing concrete structures or as a fastener.