零件的制造精度是根据以下三个方面来评定的:1、尺寸误差;2、表面几何形状误差(包括表面形状、表面波度、表面光洁度);3、表面相互位置误差。评定这些误差,应有统一标准,但以前我国仅制订了尺寸公差和表面光洁度的标准,而对零件表面形状和位置公差却没有正式国家标准,以致各厂、各行业所用的形位公差术语、定义及标准很不统一,概念混乱,有的甚至不合理。生产的发展强烈要求有统一的国家标 Part manufacturing accuracy is assessed according to the following three aspects: 1, the size of the error; 2, the surface geometry error (including surface shape, surface waviness, surface finish); 3, the surface mutual position error. In order to assess these errors, there should be a uniform standard. However, in the past, China only formulated standards for dimensional tolerances and surface finishes. However, there is no formal national standard for the shape and location tolerances of parts. As a result, Definitions and standards are not uniform, the concept of chaos, and some even unreasonable. The development of production strongly requires a unified national standard