This part of ISO 230 is concerned with the different types of vibration that can occur between the tool-holding part and the workpiece-holding part of a machine tool. (For simplicity, these will generally be referred to as “tool” and “workpiece”, respectively.) These are vibrations that can adversely influence the production of both an acceptable surface finish and an accurate workpiece. This part of ISO 230 is not aimed primarily at those who have expertise in vibration analysis and who routinely carry out such work in research and development environments. It does not, therefore, replace standard textbooks on the subject (see the Bibliography). It is, however, intended for manufacturers and users alike with general engineering knowledge in order to enhance their understanding of the causes of vibration by providing an overview of the relevant background theory. It also provides basic measurement procedures for evaluating certain types of vibration problems that can beset a machine tool: — vibrations occurring as a result of mechanical unbalance; — vibrations generated by the operation of the machine's linear slides; — vibrations transmitted to the machine by external forces; — vibrations generated by the cutting process including self-excited vibrations (chatter). Additionally, this report discusses the application of artificial vibration excitation for the purpose of structural analysis. Instrumentation is described in Annex F. An overview of the structure and content of this part of ISO 230 is given in Annex A. NOTE Other sources of vibration (e.g. the instability of drive systems, the use of ancillary equipment or the effects of worn bearings) are discussed briefly, but a detailed analysis of their vibration-generating mechanisms is not given.