Warm hydroformability and mechanical properties of pre- and post- heat treated Al6061
tubes were investigated in this study. For the investigation, as-extruded, fully annealed and T6-
treated Al 6061 seamless tubes were prepared. To evaluate the hydroformability, uni-axial tensile
test and free bulge test were performed at room temperature and 200ÓC. Also mechanical properties
of hydroformed part at various pre- and post-heat treatments were evaluated by tensile test. The
tensile test specimens were obtained from hexagonal shaped tube hydroformed at 200ÓC forming
temperature. As a result, hydroformability of fully annealed tube is 25% higher than that of
extruded tube. The tensile strength and elongation were more than 330MPa and 12%, respectively,
when hydroformed part was T6 treated after warm hydroforming. However, hydroformed part using
T6 pre treated tube represents low elongation, 8%. Therefore, the T6 treatment after hydroforming
for as-extruded tube is proved to be the most cost-effective among various processing conditions.