The purpose of annealing a metal is to

The purpose of annealing a metal is fundamentally linked to its ability to make the material easier to work with, which encompasses several beneficial effects. Annealing involves heating the metal to a specific temperature and then allowing it to cool slowly, which alters its internal structure. This process reduces internal stresses, refines grain structure, and improves ductility, making the metal much softer and more malleable.

When a metal is annealed, it becomes more amenable to further processing operations such as shaping, bending, or welding, as it can be deformed more easily without cracking or breaking. This characteristic is particularly important in manufacturing and fabrication processes, where ease of manipulation is crucial.

The other options pertain to effects of metal treatment that would not typically result from annealing. For instance, enhancing hardness or increasing tensile strength are more aligned with processes like quenching or hardening, which involve rapid cooling and can lead to increased strength but also increased brittleness. Reducing weight is not typically a direct result of any heat treatment processes and does not apply to annealing. Therefore, the primary focus of annealing is indeed to make metals easier to work, resulting in improved fabrication capabilities.