This standard specifies a test method for evaluating the cracking resistance of organic coatings attached to sheet metal or rubber profile material substrates. This method tests the flexibility and crack resistance of coatings by applying bending stress to them, and is suitable for evaluating the performance of coatings when they are bent or elongated on substrates. These tests are particularly important for the application of coatings on flexible substrates, helping to determine the durability of coatings in practical use. It is important to note that the correlation between the elongation of test methods D522/D522M and tensile test method D2370 is unclear.