Where strength is concerned, ZAMAK 5 is the logical choice and with its higher copper content resulting in higher strength and increased hardness at the expense of some loss of ductility (increased elongation) compared to Alloy 3. This reduction in ductility can affect formability during secondary operations such as bending, riveting, swaging or crimping operations and should be carefully considered by the designer.

Zamak 5 has the same composition as zamak 3 with the addition of 1% copper in order to increase strength (by approximately 10%), hardness and corrosive resistance, but reduces ductility. It also has less dimensional accuracy. Zamak 5 is more commonly used in Europe.