Abstract Hot dip galvanizing steel articles after fabrication is one of the most widely used methods to provide corrosion protection. As a final step in the process, the hot dip galvanized coating is inspected for compliance with specifications. Interpretation of inspection results should be made with a clear understanding of the causes of various conditions that may be encountered during the coating process and their effects on the ultimate objective of providing corrosion protection. The American Society for Testing and Materials (ASTM) and the International Organization for Standardization (ISO) both have specifications that contain the minimum requirements necessary for a hot dip galvanized coating on fabricated steel articles. Coating inspections of hot dip galvanized steel usually involve two elements, thickness measurements and a visual surface inspection. Correct measurement techniques and accurate interpretation of the results are necessary to provide an acceptable hot dip galvanized coating.