リングゲージの表と裏で合否判定が分かれる？通り側リングゲージ（gr）で表側は通るが、裏側が通らない。なぜ？また、これは合格か？不合格か？ | オーエスジー

There are also tolerances in the angle and pitch of the gauge , and there are minute differences on the front and back.

When the effective diameter of the external thread to be judged is close to each other (just about large), the difference may not interfere with it.

It is desirable to pass from either side, but anything that passes on one side cannot be said to be completely non-conforming, and should be considered passing. external thread In many cases, it can be solved by reducing the target value of the effective diameter.

It may also occur when welding occurs on the flank surface (slope) of the external thread or gauge .

(FAQID:269)