《公差与配合》新国家标准有一个重要的特点,就是它的各级标准公差之间分布规律性强,便于在必要时向高、低等级延伸或插入中间等级。现在我们将基本尺寸小于、等于500mm的标准公差的延伸和插入计算方法,按其计算公式的分布规律逐级加以讨论,并举例计算,供设计人员使用时参考。 An important characteristic of the new national standard “Tolerance and cooperation” is that it has a strong regularity of distribution between standard tolerances at all levels, facilitating the extension or insertion of intermediate levels to high and low levels when necessary. Now we will be the basic size of less than, equal to 500mm standard tolerance extension and insertion method, according to the distribution of the formula to be discussed step by step, and for example, calculated for reference when designers use.