The standard provides a method for the measurement of the susceptibility of aluminium alloys, particularly Al-Mg and Al-Mg-Mn alloys, to intergranular corrosion. This test method, known as the nitric acid weight loss test (NAMLT), quantitatively assesses the material's response to intergranular corrosion by immersing the sample in an environment containing nitric acid. This method helps identify the corrosion susceptibility of the alloy by measuring mass loss due to the precipitation of aluminium mg intermetallic compounds along grain boundaries. The test results can reveal the corrosion behavior of the alloy in a chlorides-containing natural environment, such as pitting, flaking or stress corrosion cracking. The standard applies to forged aluminium alloys and specifies specimen types, prepatives, test environments and exposure methods.