従来jisとisoのゲージの違い　wp・ip・npとは？ | オーエスジー

WP stands for NOT-GO machine gauge of conventional JIS, and IP stands for NOT-GO inspection plug gauge.

NP is a symbol for the NOT-GO of ISO (current JIS), and there is no distinction between machine construction and inspection.

* GO is GP for both JIS and ISO, but they cannot be shared because the thread accuracy is different. Please use the one indicated in the drawing.