This study investigated the improvement in strength and elongation through the T6 heat treatment of an aluminum 6056 alloy. The tensile strength and elongation results were measured by conducting two tensile tests per condition for 72 T6 heat treatment conditions, and Minitab analysis was used to analyze the influence of changes in tensile strength and elongation due to the T6 heat treatment conditions. The tensile strength was affected by the solution temperature, solution time, aging temperature, and aging time, whereas elongation was affected by the aging temperature and aging time. To derive a condition that satisfies the improvement of strength and elongation simultaneously, we used Minitab analysis to analyze the variables of solution temperature, solution time, aging temperature, and aging time, and a tensile strength of 400 MPa and an elongation of 20% were identified. Scanning electron microscopy and energy dispersive spectroscopy analyses confirmed the distribution of light-colored precipitates, and it is unlikely that the differences in the precipitates due to strength variation can be identified using differences in the specimen location.