Steel Pipe Schedules and Dimensions

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 DN 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 20 1.05 0.065 0.11 X 0.095 0.113 X X 0.17 X 0.219
1 25 1.315 0.065 0.11 X 0.114 0.133 X X 0.2 X 0.25
1 1/2 40 1.9 0.065 0.11 X 0.125 0.145 X X 0.225 X 0.281
2 50 2.375 0.065 0.12 X X 0.154 X X 0.25 X 0.344
2 1/2 65 2.875 0.083 0.12 X X 0.203 X X 0.3 X 0.375
3 80 3.5 0.083 0.12 X X 0.216 X X 0.35 X 0.438
4 100 4.5 0.083 0.12 X X 0.237 X X 0.437 X 0.531
5 125 5.563 0.109 0.12 X X 0.258 X X 0.5 X 0.625
6 150 6.625 0.109 0.13 X X 0.28 X X 0.562 X 0.719
8 200 8.625 0.109 0.15 0.25 0.277 0.322 0.406 0.5 0.593 0.719 0.906
10 250 10.75 0.134 0.17 0.25 0.307 0.365 0.5 0.594 0.718 0.843 1.125
12 300 12.75 0.156 0.18 0.25 0.33 0.406 0.562 0.687 0.843 1.0 1.312
14 350 14.0 0.156 0.25 0.312 0.375 0.437 0.593 0.75 0.937 1.093 1.406

 

Metric

Millimeters
NB DN OD (mm) Pipe Schedule
SCH 5 SCH 10 SCH 20 SCH 30 SCH 40 SCH 60 SCH 80 SCH 100 SCH 120 SCH 160
3/4 20 26.67 1.65 2.11 X 2.41 2.87 X 3.91 X 4.32 5.56
1 25 33.40 1.65 2.77 X 2.90 3.38 X 4.55 X 5.08 6.35
1 1/2 40 48.26 1.65 2.77 X 3.18 3.68 X 5.08 X 5.72 7.14
2 50 60.32 1.65 2.77 X X 3.91 X 5.54 X 6.35 8.74
2 1/2 65 73.02 2.11 3.05 X X 5.16 X 7.01 X 7.62 9.53
3 80 88.9 2.11 3.05 X X 5.49 X 7.62 X 8.89 11.13
4 100 114.3 2.11 3.05 X X 6.02 X 8.56 X 11.10 13.49
5 125 141.3 2.77 3.4 X X 6.55 X 9.53 X 12.70 15.88
6 150 168.27 2.77 3.4 X X 7.11 X 10.97 X 14.27 18.26
8 200 219.07 2.77 3.76 6.35 7.04 8.18 10.31 12.7 15.06 18.24 23.01
10 250 273.05 3.4 4.19 6.35 7.8 9.27 12.7 15.06 18.24 21.41 28.58
12 300 323.85 3.96 4.57 6.35 8.38 10.31 14.27 17.45 21.41 25.40 33.32
14 350 355.60 3.962 6.35 7.925 9.525 11.10 15.06 19.05 23.80 27.76 35.71