Abstract Marine atmosphere and synthetic sea water stress corrosion tests on smooth and precracked specimens from 7075, 7050, and 7049 alloy plates (32 and 76 mm thick) show that for a given strength level, alloys 7050-T7X and 7049-T7X have superior short-transverse stress corrosion resistance (SCR) to 7075-T7X. At typical strength levels above the minimum of 7075-T6, for example, SCR of these alloys is considerably better than that of 7075-T76, and approaches that of 7075-T73. Alloys 7050-T73651 and 7049-T7351 have SL threshold stress intensities (KISCC) of about 24 MPa √m at a yield strength of 450 MPa. The corresponding KISCC value for 7075-T7X at this strength level is about 19 MPa √m. In both environments, KISCC is independent of plate thickness, per se; absolute strength level appears to be the controlling factor, KISCC being inversely proportional to yield strength. Examination of fracture surfaces and metallographic cross sections showed a considerable amount of crack blunting, crack jogging, crac...