アメリカ標準管用ねじ　下穴径とタップの工具径は？　npt　nptf等 | オーエスジー

What is the tool diameter of the pilot hole and the tap of the American standard pipe screw? NPT NPSC NPTF NPSF

・ Pilot hole diameter

When machining pilot holes with a drill, refer to the value of "When not using a reamer" in the table below.

• Tool diameter of the tap

For the tool diameter when calculating the cutting data, refer to the number on the outer diameter of the thread.

Please note that the pilot hole diameter of the PT and Rc screws and the tool outer diameter of the tap are different.