The characteristics and subsequent applications of each series vary considerably. For example, there are two distinct types of aluminum in the range above. They are: heat-treatable aluminum alloys (which can gain strength by adding heat) and non-heat-treatable aluminum alloys.
The 1xxx, 3xxx and 5xxx series wrought aluminum alloys are not heat treatable and will only undergo strain hardening. The 2xxx, 6xxx and 7xxx series of wrought aluminum alloys are heat-treatable alloys, while the 4xxx series includes heat-treatable and non-heat-treatable alloys. The 2xx.x, 3xx.x, 4xx.x and 7xx.x series cast alloys are heat treatable. Strain hardening is generally not suitable for castings.
