1.1 These practices cover the following four tests: 1.1.1 Practice W—Oxalic acid etch test for detecting susceptibility to intergranular attack in stabilized ferritic stainless steels by classification of the etching structures (see Sections 3 – 10). 1.1.2 Practice X—Ferric sulfate-sulfuric acid test for detecting susceptibility to intergranular attack in ferritic stainless steels (Sections 11 – 16). 1.1.3 Practice Y—Copper-copper sulfate-50?% sulfuric acid test for detecting susceptibility to intergranular attack in ferritic stainless steels (Sections 17 – 22). 1.1.4