At this point the metal can also be tempered, which restores some of its toughness while maintaining a certain amount of hardness. While the process doesn’t require specialized tools ...

including a discussion of how heat and carbon content impact a steel's microstructure. This class also describes common heat treating methods, such as annealing, quenching, normalizing, and tempering.

At this point the metal can also be tempered, which restores some of its toughness while maintaining a certain amount of hardness. While the process doesn’t require specialized tools ...