he objective of this work was to investigate the mechanical and metallurgical properties in order to demonstrate the feasibility of friction stir welding (FSW) for joining of 6061Aluminum Alloy. Four rotational speeds, 720, 910, 1120, and 1400 r.p.m and three traverse speeds 16, 20, and 31.5 mm/min were applied. Metallographic examinations of friction stir welded plates were carried out using optical and scanning electron microscopy. Hardness profiles of welded joints were measured using Vickers hardness testing. The hardness profile at transfer cross sections showed marked decrease in hardness values depending on welding conditions and position of hardness measurements. The FSW welds exhibited higher joint efficiencies relative to conventional welding techniques.