NPT Chart

Pipe Size (inch)Thread Density (inch −1 )Thread Pitch (inch)Thread Pitch (mm)
  1 ⁄ 16270.037037040.9407
  1 ⁄ 8270.037037040.9407
  1 ⁄ 4180.055555551.4111
  3 ⁄ 8180.055555551.4111
  1 ⁄ 2140.071428571.8143
  3 ⁄ 4140.071428571.8143
1 11  1 ⁄ 20.086956522.2087
 1  1 ⁄ 4 11  1 ⁄ 20.086956522.2087
 1  1 ⁄ 2 11  1 ⁄ 20.086956522.2087
2 11  1 ⁄ 20.086956522.2087
 2  1 ⁄ 280.1253.175
380.1253.175
 3  1 ⁄ 280.1253.175
480.1253.175
 4  1 ⁄ 280.1253.175
580.1253.175
680.1253.175
880.1253.175
1080.1253.175
1280.1253.175
1480.1253.175
1680.1253.175
1880.1253.175
2080.1253.175
2480.1253.175