npt problem

[Dan_Margulius]

Hello,

I added a hole thread feature, npt 3/8 . Inventor is removing material. This is different from the npt charts.

Any idea why the difference ?

Thanks,

Dan

[Anonymous]

Tap drill size is .5468 when it should be .5625.

[Dan_Margulius]

OK, can you elaborate please. Why inventor is creating that "step" ?

Thanks,

Dan

[Anonymous · Accepted solution]

The minor diameter is too small, recommended tap drill for 3/8 NPT is 9/16.  If you change the tap drill in the Thread.xls to .5625 the step should go away.

[Dan_Margulius]

Thank you