The ISO 4518 standard specifies a profiling method for thickness measurement of metallic coatings. This method uses Profile Gauge to determine the thickness of coatings by measuring changes in the surface topography of coatings, and is suitable for the inspection of various metallic coatings. The standard describes in detail the steps of Coating thickness measurement using Profile Gauge, including Measurement principles, equipment requirements, sample preparation, data collection and analysis, etc. This method can provide high-precision measurement results and is widely used in quality control and product inspection of metallic coatings. Coating thickness is accurately determined in accordance with ISO 4518, which in turn guarantees the performance and durability of metallic coatings.