利用三针测螺纹中径时,由于三针不容易固定,因此测量时非常麻烦。而用如图所示的结构则能实现快速测量。利用一支普通圆规,再作一个夹头,便于固定两根测量针,然后将其装在圆规的一只腿上,另一只腿不用改装,只夹一根测量针。测量时,利用圆规的两条可调整的腿,就能很容 The use of three-pin thread diameter measurement, the three-pin is not easy to fix, so the measurement is very troublesome. With the structure shown in the figure you can achieve rapid measurement. Use an ordinary compass, and then make a collet, easy to fix the two measuring needles, and then mounted on one leg of the compass, the other leg without modification, only a measuring pin. Measurement, the use of compasses of the two adjustable legs, can be very tolerant