The ageing of aluminium alloy is bring the specimens do heating at a given temperature. When it reaches temperature we want , we will bring the specimens out of the oven and bring to Quench in water. Then left at room temperature for various times after bring specimens to measure the hardness value. Why leave these specimens at room temperature at the various time in order to compare the strengths of each of specimen at the various time . After the specimen was left at room temperature for a period equal we will to bring to the heat for 1 minute, 1 hour, 2 hours and 4 hours to evaluate the hardness compare the time it takes to bake. The benefits derived from precipitation ageing is that the part will be strong increase after left at room temperature, the hardness is increased slowly by the time that was left. And when it is baked on hardness will increase dramatically. The hardness is increased By the time it takes to bake.