Abstract: Disclosed is a method of producing a forged and rolled Al-Zn-Cu-Mg alloy plate product having improved fatigue properties in the long transverse direction. The method comprises providing a body of an Al-Zn-Cu-Mg alloy, working said body by a forging operation to reduce its thickness in a C direction by at least 30% and rolling or working the forged body to provide a forged and rolled plate product having improved fatigue properties in the long transverse direction.

Abstract: Disclosed is a method of making aluminum base alloy flat rolled product substantially free of Luder's lines after stretching, the method comprising the steps of providing a body of a lithium-containing aluminum base alloy and working the body to produce a flat rolled product prior to solution heat treating and quenching. The flat rolled product is preaged for a time and temperature which does not substantially affect mechanical properties but which permits stretching the flat rolled product without formation of Luder's lines. Thereafter, the preage flat rolled product is stretched and aged to a condition having a substantially stable level of mechanical properties.