Friction-stir welding (FSW) is a solid-state joining process (the metal is not melted) and is used when the original metal characteristics must remain unchanged as much as possible. It mechanically intermixes the two pieces of metal at the place of the join, then softens them so the metal can be fused using mechanical pressure, much like joining clay, dough, or plasticine. It is primarily used on aluminum, and most often on large pieces that cannot be easily heat-treated after welding to recover temper characteristics. In this project, FEA analysis is performed for friction stir welding of aluminium and copper. The welds are produced by varying the process parameters; the rotational speed at 900 rpm and the welding speed varied between 60 and 80 mm/min. Thermal analysis are done. A parametric model with the weld plates and cutting tool is done in Creo-2The effects of different tool pin profiles on the friction stir welding are also considered for analysis. Different tool pin profiles are square and circular. So in this project we want to create simple model of FSW tool and two work pieces to be joined by butt by using Creo software and also analysis the working pieces that is effected by the thermal stress that are applied on it.