リングゲージは、両面使用可能？ | オーエスジー

In the case of parallel screws, both sides can be used.

 

If there is a difference in judgment, scratches or welding may be on one side.

 

In addition, there may be a difference in judgment depending on the finished shape of the thread, such as the external thread causing mountain thinning due to pitch shift during machining.