wねじ用のタップ　ウィットねじ | オーエスジー

Only those with size in inches are in the standard lineup.

General use (HT, SFT, POT)
General Use Long Shank (HT, SFT, POT)
For SUS (SFT, POT)
NT (Nut Tap)

 

The size and pitch notation W20-12 (Detail No. 1) and W20-16 (Detail No. 2) are not in the standard product, so they are compatible with special products.