Prices of scrap metal are determined, mostly , based on the type of metal. .There are hundreds of sub-categories and compositions of metal, and many buyers use portable analytical instruments to figure out the exact composition of the scrap metals. Also important is the condition of the scrap metal. It needs to be as clean of corrosion as possible in order to fetch the highest price from a buyer. The metals market determines pricing for the major metals, such as cast aluminum, red brass, and stainless steel. For unidentified metal composites and minor metals, prices are usually decided between the buyer and the seller.