基本概念形状和位置公差带是实际被测要素允许变动的区域。我国形位公差国家标准是建立在几何概念的基础上的,所以用二维或三维的几何区域———公差带来体现对零件的几何精度要求。实际被测要素必须全部位于设计给定的形位公差带内,其几何精度才是合格的。除非另有附加的要求, The basic concept of shape and position tolerance zone is the actual measured element allows changes in the area. China’s national standard form of tolerances is based on the geometric concept of the foundation, so with two-dimensional or three-dimensional geometric region --- tolerance to reflect the geometric accuracy of the parts requirements. The actual measured elements must all be located within the tolerance zone of the given shape and the geometric accuracy is acceptable. Unless otherwise required,