1.1 This standard covers definitions, classes of ballscrews, recommended combinations of screw diametersand leads, recommended drawing format, and performancecharacteristics of ball screw and nut assembliesas applied to machine tools.1.2 The values stated in U.S. customary units are tobe regarded as the standard. Metric values are convertedfrom the customary values per recommendationsof 'ASME Guide SI-I, ASME Orientation andGuide for Use of SI (Metric) Units'.