National and international standards are used to standardize the definitions, environmental requirements, and test methods used for the performance evaluation of lathes. Election of the standard to be used is an agreement between the supplier and the user and has some significance in the design of the lathe. In the United States, ASME has developed the B5.57 Standard entitled "Methods for Performance Evaluation of Computer Numerically Controlled Lathes and Turning Centers", which establishes requirements and methods for specifying and testing the performance of CNC lathes and turning centers.[20]