Tempering is a heat treatment that uses a tempering furnace to increase the toughness of certain metals. The steel is heated to just below a certain temperature and then air cooled.

The temperature at which the item is tempered depends entirely on the application of the metal and the desired result, drill bits need to be tempered at a lower temperature than mattress springs.

Tempering is only one heat treatment option for metals. Some other options are annealing and normalization. Tempering is best for products that are under a lot of stress, not just drills and springs, but also knives, bolts, washers and
many more common products.

Tempering heat treatment is a necessary process in the steel manufacturing process. The benefits of tempering not only increase the usability of the product, but also the service life of the product.