In the present work, the friction-stir welding of Al6061-annealed pure copper dissimilar metals with square-wave tool-pin movement pattern was investigated. The aim of this experiment was to identify the significant effect of square-wave tool movement, along with three different tool-pin profiles, on friction stir welding. Different tool-pin profiles of square, round and hexa-spiral shapes were selected and their significant outcomes were revealed. Friction-stir-welding parameters including tool rotations of 1500 min(-1) and 2000 min(-1), tool-pin-movement step sizes of 1.0 mm and 2.0 mm and weaving rates of 100 mm/min and 150 mm/min were selected. The advantages of the tool-movement pattern and tool-pin profile shape were examined with mechanical testing and a microstructure analysis. The mechanical results showed that the tool rotation of 1500 min(-1), step size of 1.0 mm, welding rate of 150 mm/min and the square-tool pin-profile give better mechanical properties. Microstructural results revealed a better grain refinement and a uniform dispersion of microconstituents resulting from the implementation of the square-wave tool-pin movement pattern along with the square-tool pin profile. The EDAX report confirmed that the weld nugget contained both aluminum and copper in equal percentages, indicating fine mixing of the two parent metals.