自从有了机械加工之后,机械加工中对零件的形位误差方面的要求,以及对形位误差的测量就开始逐步被人们所认识和掌握。国家标准形状和位置公差GB1183—74、1183～1184—75的颁布,进一步明确了对机械零件形位误差方面的要求,统一了形位误差的定义,纠正了过去一些混乱的概念。因此,根据国家标准形状和位置公差的统一定义,在生产实践的基 Since machining, the requirements for the form and position error of parts during machining have been gradually recognized and mastered. The promulgation of GB1183-74, 1183 ~ 1184-75 of the national standard shape and position tolerance further clarified the requirements for the shape and position error of mechanical parts, unified the definition of shape and position error, and corrected the concept of some confusion in the past. Therefore, according to the uniform definition of national standard shape and position tolerance, the basis of production practice