Friction stir welding is a solid state innovative joining technique, widely being used for joining aluminium alloys in aerospace, marine automotive and many other applications of commercial importance. The welding parameters and tool pin profile play a major role in deciding the weld quality. In this paper, an attempt has been made to understand the influences of welding speed and pin profile of the tool on friction stir welded joints of AA6082-T6 alloy. Three different tool pin profiles (tapered cylindrical four flutes, triangular and hexagonal) have been used to fabricate the joints at different welding speeds in the range of 30 to 74 mm/min. Microhardness (HV) and tensile tests performed at room temperature were used to evaluate the mechanical properties of the joints. In order to analyse the microstructural evolution of the material, the weld’s cross-sections were observed optically and SEM observations were made of the fracture surfaces. From this investigation it is found that the hexagonal tool pin profile produces mechanically sound and metallurgically defect free welds compared to other tool pin profiles.
 Dawes C.J., Thomas W.M.: Friction stir process welds of aluminum alloys, Welding Journal, Vol. 75, No. 3, 1996, pp. 41-45.
 Thomas W.M., Nicholas E.D., Needham J.C., Murch M.G., Templesmith P., Dawes C.J.: Improvements relating to friction welding, WO/1993/010935, International Patent Number, PCT/GB92/02203 TWI, 1992.
 Thomas W.M., Nicholas E. D., Watts E.R., Staines D.G.: Friction based welding technology for aluminium, Material Science Forum, Vols. 396-402, 2002, pp. 1543-1548.
 Ericsson M., Sandstro R.: Influence of welding speed on the fatigue of friction stir welds, and comparison with MIG and TIG, International Journal of Fatigue, Vol. 25, 2003, pp. 1379-1387.
 Ellis M.B.D., Strangwood M.: Welding of rapidly solidified Alloy-8009 preliminary study, Material Science & Technology, Vol. 12, 1996, pp. 970-977.
 Cavaliere P., Squillace A., Panella F.: Effect of welding parameters on mechanical & microstructural properties of AA6082 joints produced by friction stir welding, Journal of Materials Processing Technology, Vol. 200, No. 1-3, 2008, pp. 364-372.
 Moreira P. M. G. P., Santos T., Tavares S. M. O., Richter-Trummer V.: Mechanical and metallurgical characterization of friction stir welding joints of AA6061-T6 with AA6082-T6, Materials and Design, Vol. 30, 2009, pp. 180-187.
 Cavaliere P., Santis A. De., Panella F., Squillace A.: Effect of welding parameters on mechanical and microstructural properties of dissimilar AA6082-AA2024 joints produced by friction stir welding, Materials and Design, Vol. 30, 2009, pp. 609-616.
 Lee W.B., Yeon Y.M., Jung S.B.: Evaluation of the microstructure and mechanical properties of friction stir welded 6005 aluminium alloy, Material Science & Technology, Vol. 19, No. 11, 2003, pp. 1513-1518.
 Simar A., Brechet Y., Meester B. de., Denquin A., Pardoen T.: Microstructure, local and global mechanical properties of friction stir welds in aluminium alloy 6005A-T6. Material Science & Engineering, Vol. 486, No. 1-2, 2008, pp. 85-95.
 Peel M.J., Steuwer A., Withers P.J., Dickerson T., Shi Q., Shercliff H.: Dissimilar friction stir welds in AA5083-AA6082. Part I: process parameter effects on thermal history and weld properties, Metallurgical and Material Transactions A, Vol. 37, 2006, pp. 2183-2193.
 Patil H. S., Soman S. N.: Experimental study on the effect of welding speed and tool pin profiles on AA6082-O aluminium friction stir welded butt joints, International Journal of Engineering, Science and Technology, Vol. 2, No. 5, 2010, pp. 268-275.
 Patil H. S., Soman S. N.: Influence of process parameter on tensile properties of friction stir welded butt joints in 6082 aluminium alloy, Elixir Mec. Engg. 30 (2011) 1823-1825.
 Lim S., Kim S., Lee C.G., Kim S.J.: Tensile behavior of friction-stir-welded Al 6061- T651, Metallurgical and Material Transactions A, Vol. 35, No. 9, 2004, pp. 2829-2835.
 Ren S.R., Ma Z.Y., Chen L.Q.: Effect of welding parameters on tensile properties and fracture behavior of friction stir welded Al-Mg-Si alloy, Scripta Materialia, Vol. 56, No. 1, 2007, pp. 69-72.
 Aydin H., Bayram A., Agah U., Akay K. S.: Tensile properties of friction stir welded joints of 2024 aluminum alloys in different heat-treated-state, Materials and Design, Vol. 30, 2009, pp. 2211-2221.
 Patii H. S., Soman S.N.: Effect of weld parameter on mechanical and metallurgical properties of dissimilar joints AA6082-AA6061 in T6 condition produced by FSW Frattura ed Integrita Strutturale, 24 (2013) 151-160.