Tempering is used to draw the hardness out of the as quenched piece of steel. How much as quenched hardness that is drawn out of the steel will depend upon the tempering temperature used and the length of time the steel is held at the tempering temperature.
Sometimes tempering is used to modify an existing heat treat condition in the steel. Typically when the material has already been stocked in a higher than required strength level.
We can temper in a vacuum atmosphere if needed on finished parts and our largest vacuum furnace is 46” outside diameter x 57” high and can handle a 2,500 Lb load.
Our air tempering capabilities are much larger, with our largest available tempering furnace measuring 72” wide x 60” high x 228” long and can handle a 25,000 Lb load.