在测量螺纹单一中径或中径时,最佳测针或测球直径的计算,首先应依据被测螺纹的基本牙型,然后依据被测螺纹基本参数的定义,最后参照被测螺纹单一中径或中径的计算公式。如果该单一中径或中径的计算公式是未考虑螺旋升角的近似简单公式,例如JJF1345-2012《圆柱螺纹量规校准方法》中第4页的中径计算公式(1),则可以使用“几 In the measurement of a single thread diameter or diameter of the thread, the calculation of the best stylus or ball diameter, the first thread should be based on the basic tooth shape, and then based on the definition of the basic parameters of the thread to be tested, the final reference to the thread in a single test Path or diameter of the formula. If this single center or median diameter calculation is an approximate simple formula that does not take into account the helix angle, such as the calculation of the middle diameter (1) on page 4 of JJF1345-2012 Cylindrical Thread Gauge Calibration Method, you can use ”a few