AbstractThe mechanical properties of the high strength casting alloys A356, A357, A20l, and A206 are compared using the best current casting technology, to provide an accurate overview of these important alloys. The alloys were cast using precision sand moulds, via an uphill filling system incorporating a filter. Subsequent mould inversion was applied to later castings in A201 and A206 alloys. Aluminium chills acting against cooling fins were used to aid feeding by enhancing the temperature gradient. Mechanical properties were obtained for as cast, solution treated, and aged alloys, where aging was carried out to very long effective times, enabling assessment of alloy behaviour over a wide range of temperatures and times. Comparison with previously published data obtained in green sand and permanent moulds indicated that the faster cooling times in these moulds give somewhat improved properties.MST/3280