Friction stir welding (FSW) is a solid-state welding process. Using tools with a concave shoulder and a threaded conical pin, we tested various welding conditions for two different aluminum alloys of A5083 and A6082. A6082 alloys were aging heat-treated materials and their softening in strength by frictional heating was evidently observed during FSW. The crystallographic orientation in the stir zone of A5083 revealed a random distribution, and that of A6082 was close to strong shear texturing. Temperature profiles were measured near the heat-affected zone (HAZ) using thermocouples. Evolution of microstructure and texture was also examined using electron backscatter diffraction.