Effect of tool rotation rate and travel speed on aging of 6082T6 friction stir welds after tensile strain hardening were investigated using Vickers microhardness (HV) measurements and precipitation hardening concepts. Tensile tests were performed at constant strain rate up to natural fracture followed by aging at low and medium temperatures. The results showed that HV measured on strain hardened FSW joints was not very sensitive to travel speeds experienced during FSW process, at constant rotation rate; anyway, strain hardening was very effective on hardness and induce an average increase by 20-25% in the stirred zone (SZ). Strain hardening was also very effective on aging at 200 degrees C, while it was not at 300 degrees C. At this temperature, HV assumed uniform values along joint cross section. (C) 2014 Elsevier B.V. All rights reserved.