To construct machining databases, which are reusable and sharable their meanings, semantic metadata management is required. In this study a semantic data modeling process for machining data is developed. It combines conventional data models with ISO/IEC 11179 standard, metadata registry(MDR). Names of object classes and properties constituting data element names are identified using conventional data model while data elements are named and specified based on ISO/IEC 11179 in order to obtain semantic interoperability of data. An experimental application to electrical discharge machining(EDM) is performed to explain the process.