This defect catalogue is a reflection of our commitment to ongoing customer Focus throughout the heavy plate production chain. Clarity of operations and repeatability in rolling mills are key factors in heavy plate manufacturing, as well as the description of possible defects.In order to discuss and describe heavy plate defects, a working Group was formed in 2012. This group is part of the Technical Committee of the Steel Institute VDEh.The working Group has created definitions of common defects and has incorporated existing experiences into the current catalogue. It also lists possible causes of defects and reasons for misdiagnosis. The size and severity of the defects should be characteristic but will vary in scope. For example, the defect can occur in a more severe or less severe form on the heavy plate.The defect descriptions listed here are complemented by regional and vendor or application-specific defect designations.The purpose of this defect catalogue is to give a better understanding in the technical communication throughout the heavy plate production chain. Existing Standards and regulations for surface finish, dimensional tolerance and the internal condition of the plate must still be observed independently.