rcのめねじ加工をしているが、刃先交換式工具で加工したら めねじの奥側が異様に内側に入り込んでいる。何かおかしいのか？ | オーエスジー

The direction of the insert attached to the holder may be reversed.

Make sure the insert surface is "R" instead of "L".

Holders with "LH" at the end of the model number are for left-hand rotary tools.

In that case, attach the insert so that the "L" is visible.

References: Tapered Threaded Pipe chip Installation Precautions

(FAQID:181)