Clad metals are laminar composites consisting of a metal or alloy, with a metal or alloys of different chemi-cal composition applied to one or more sides by welding casting, drawing, rolling, surfacing, chemical deposition,or electroplating. In this chapter, the term dissimilar metal refers to the welding of chemically different metals (for example, aluminum, copper and nickel) or micro-structurally different alloys of a particular element (for example, carbon steel and stainless steel). Dissimilar metal combinations comprise one or more base metals and one or more filler metals that make up the final weld metal after melting and mixing during welding. A series of weld metals that vary significantly in composition may exist within a single welded joint; each weld bead may have individual compositional characteristics.