Currently reading: National Pipe Thread Taper by ProSciTech Pty Ltd

National Pipe Thread Taper

National pipe thread taper (NPT) conversion table.
NPT - National Pipe Thread Taper - ANSI B1.20.1
Pipe Size
(inches)
Threads/InchApprox. Length
of Thread (inches)
Approx Number
of Threads to be cut
Nominal Outside Pipe Diameter (inches)Tap Drill
1/8"273/8"100.405"
1/4"185/8"110.540"7/16"
3/8"185/8"110.675"37/64"
1/2"143/4"100.840"23/32"
3/4"143/4"101.050"59/64"
1"11-1/27/8"101.315"1-5/32"
1-1/4"11-1/21"111.660"1-1/2"
1-1/2"11-1/21"111.900"1-47/64"
2"11-1/21"112.375"2-7/32"
2-1/2"81-1/2"122.875"2-5/8"
Was this article helpful?
Yes
No
1 out of 1 found this helpful
comments powered by Disqus