No. 2 is the only ZAMAK alloy which is used for gravity casting; mainly for metal forming dies or plastic injection tools. This alloy is sometimes referred to as Kirksite. For die casting, No. 2 offers the highest strength and hardness of the ZAMAK family. However, its high copper content (3%) results in property changes upon long term aging. These changes include slight dimensional growth (0.0014 in/in/after 20 yrs.), lower elongation and reduced impact performance (to levels similar to aluminum alloys) for die cast products. Although No. 2 alloy exhibits excellent castability, it has seen limited use by die casters in North America. It does, however, provide some interesting characteristics which may assist designers. Its creep performance is rated higher than the other ZAMAKs and No. 2 maintains higher strength and hardness levels after long term aging. Also, preliminary investigations suggest No. 2 alloy is a good bearing material, and may eliminate bushings and wear inserts in die cast designs.