ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 13041-3 was prepared by Technical Committee ISO/TC 39, Machine tools, Subcommittee SC 2, Test conditions for metal cutting machine tools. ISO 13041 consists of the following parts, under the general title Test conditions for numerically controlled turning machines and turning centres: — Part 1: Geometric tests for machines with a horizontal workholding spindle — Part 2: Geometric tests for machines with a vertical workholding spindle — Part 3: Geometric tests for machines with inverted vertical workholding spindles — Part 4: Accuracy and repeatability of positioning of linear and rotary axes — Part 5: Accuracy of feeds, speeds and interpolations — Part 6: Accuracy of a finished test piece — Part 7: Evaluation of contouring performance in the coordinate planes — Part 8: Evaluation of thermal distortions