ASTM C664-10 (2015) standard specifies the test method for measurement of diffusion Coating thickness. Diffusion coatings are widely used to protect and enhance the performance of metal surfaces, and measurement of their thickness is essential for evaluating coating mass. The standard details the technical requirements for measuring diffusion Coating thickness using microscope, section analysis, etc., including sample preparation, measurement procedures, equipment requirements, and Data analysis methods. The standard is applicable to various types of diffusion coatings, such as hot dip plating, electroless plating, etc., to ensure the conformity and Reliability of the coating mass. By adhering to this standard, the thickness of the diffusion coating can be accurately evaluated, thus providing protection for performance such as corrosion resistance and abrasion resistance in industrial applications.