NPS Steel Pipe schedules and dimensions 1/2″ – 14″NB

The nominal bore is loosely related to the i/d of the pipe, there are different wall thicknesses or schedules available for each size, the o/d stays constant for each NB.

The heavier the schedule of pipe, the smaller the bore.

Here we have both imperial and metric units.

Imperial

Inches
NB OD (Inches) Pipe Schedule
SCH 5 SCH 10 SCH 20 SCH 30 SCH 40 SCH 60 SCH 80 SCH 100 SCH 120 SCH 160
3/4 1.05 0.065 0.11 X 0.095 0.113 X X 0.17 X 0.219
1 1.315 0.065 0.11 X 0.114 0.133 X X 0.2 X 0.25
1 1/2 1.9 0.065 0.11 X 0.125 0.145 X X 0.225 X 0.281
2 2.375 0.065 0.12 X X 0.154 X X 0.25 X 0.344
2 1/2 2.875 0.083 0.12 X X 0.203 X X 0.3 X 0.375
3 3.5 0.083 0.12 X X 0.216 X X 0.35 X 0.438
4 4.5 0.083 0.12 X X 0.237 X X 0.437 X 0.531
5 5.563 0.109 0.12 X X 0.258 X X 0.5 X 0.625
6 6.625 0.109 0.13 X X 0.28 X X 0.562 X 0.719
8 8.625 0.109 0.15 0.25 0.277 0.322 0.406 0.5 0.593 0.719 0.906
10 10.75 0.134 0.17 0.25 0.307 0.365 0.5 0.594 0.718 0.843 1.125
12 12.75 0.156 0.18 0.25 0.33 0.406 0.562 0.687 0.843 1.0 1.312
14 14.0 0.156 0.25 0.312 0.375 0.437 0.593 0.75 0.937 1.093 1.406