This Standard defines a machine coordinate system and motion nomenclature for numerically controlled machines. It is intended to eliminate misunderstandings between manufacturers, programmers, and users of machine tools, to simplify programming, to facilitate the interchangeability of recorded data between machines of like configuration, and to simplify the training of programmers by the standardization of machine coordinate system and motion nomenclature. This Standard defines a machine coordinate system and machine movements so that a machine tool programmer can describe machining operations without having to know whether the tool approaches the workpiece or the workpiece approaches the tool.

The rules contained in this Standard were developed with the cooperation of private industry and Government and are based on widely accepted industry practice and usage. They are also based, in part, on standards used in the international machine tool market.

This Standard was prepared by the IE-31 Committee on Numerical Control Systems and Equipment and approved by the Engineering Department Executive Committee (EDEC).