The annealing process is a heat treatment, which can change the physical and sometimes the chemical properties of the object. The annealing process can increase the ductility and reduce the hardness to make it fit in more places.

Before cooling, the material need to be set for a few time, the temperature of the material need to be maintain above the recrystallization temperature. The cooling rate depends upon the types of metals being annealed. For example, ferrous metals such as steel are usually left to cool down to room temperature in still air while copper, silver and brass can either be slowly cooled in air or quickly quenched in water.

The atoms will migrate in the crystal lattice and the number of dislocation will reduce during the heating process. These changes will make ductility and hardness vary. The heat treated material recrystallizes as it cools. The crystal grain size and phase composition depend on the heating and cooling rates and these, in turn, determine the material properties.

The process like the annealing, hot or cold working will change the structure of the material, thus the annealed products may need the further treatment to maintain the original properties. From another perspective, the heating treatment can soften metals and prepare them for further working such as forming, shaping and stamping, as well as preventing brittle failure.