Abstract
The present investigation had two objectives: first, to study the effect of the geometry of the tool pin, and second, the effect of tool rotation and welding speeds on the mechanical properties of friction stir welded joints made for samples of commercial grade aluminium alloys. The results obtained from the performed experiments showed that tools with tapered pins created superior mechanical properties for the friction stir welded joints. It was also found that overall mechanical response depended on the ratio of the tool rotation speed to the tool traverse speed. Suitable values for this ratio were isolated that lead to high quality mechanical properties for the created joints.