A method of heat treating high pressure die cast objects using pressure is disclosed. A high pressure die cast object is obtained and solution heat treated to above 700° F. for at least 2 hours at pressures between 0.5 and 35 KSI or at any pressure or range of pressures therebetween. This method of solution heat treatment with pressure reduces and/or eliminates blistered defects on the high pressure die cast object. The method of heat treating by solution heat treatment with pressure also allows an increase of yield strength and corresponding weight reduction upon redesign or substantially larger safety factors for the cast object.