The ASTM D4541 standard describes the evaluation of the peel strength (adhesion) of a Coating system on a metal substrate using a portable Adhesion Tester. This test method provides two protocols: Protocol 1 (Fracture Test) determines the maximum tension that the coating can withstand before the material stopper peeling after a vertical force is applied; Protocol 2 (Pass/Fail) determines whether the coating remains intact under a defined load standard. This standard applies to a variety of coating types and substrates, but with metal as the primary test object. Comparison of test results should be performed under the same test conditions, taking into account the effects of coating curing time, glue type, and environmental conditions. The standard emphasizes the conformity of test equipment and test methods to ensure reliable comparison and evaluation of coating adhesion.