Pipe Schedules for
Steel and Metal

The internal diameter of a pipe is a critical dimension, also known as nominal bore (NB). The pipe wall thickness can also play a significant role, as it affects the pipe's strength and the kind of technology that can be applied to that pipework. Wall thickness is expressed in "schedules", referred to as pipe schedules.

Please see the table below, which will help you calculate wall thickness based on Pipe Schedule and Nominal Bore.

The following abbreviations have been used: NB - nominal bore, STD - Standard, EH - Extra Heavy, DBL EH - Double Extra Heavy, OD - Outside Diameter.

Pipe Schedule

Pipe Wall Thickness (inches)
Nominal OD Inches 5s 5 10s 10 20 30 40s & Std 40 60 80s & EH 80 100 120 140 160

DBL E.H.
1/8 .405 .035 .049 .049 .068 .068 .095 .095
1/4 .540 .049 .065 .065 .088 .088 .119 .119
3/8 .675 .049 .065 .065 .091 .091 .126 .126
1/2 .840 .065 .065 .083 .083 .109 .109 .147 .147 .187 .294
3/4 1.050 .065 .065 .083 .083 .113 .113 .154 .154 .218 .308
1 1.315 .065 .065 .109 .109 .133 .133 .179 .179 .250 .358
1 1/4 1.660 .065 .065 .109 .109 .140 .140 .191 .191 .250 .382
1 1/2 1.900 .065 .065 .109 .109 .145 .145 .200 .200 .281 .400
2 2.375 .065 .065 .109 .109 .154 .154 .218 .218 .343 .436
2 1/2 2.875 .083 .083 .120 .120 .203 .203 .276 .276 .375 .552
3 3.500 .083 .083 .120 .120 .216 .216 .300 .300 .437 .600
3 1/2 4.000 .083 .083 .120 .120 .226 .226 .318 .318 .636
4 4.500 .083 .083 .120 .120 .237 .237 .281 .337 .337 .437 .531 .674
4 1/2 5.000 .247 .355 .710
5 5.563 .109 .109 .134 .134 .258 .258 .375 .375 .500 .625 .750
6 6.625 .109 .109 .134 .134 .280 .280 .432 .432 .562 .718 .864
7 7.625 .301 .500 .875
8 8.625 .109 .109 .148 .148 .250 .277 .322 .322 .406 .500 .500 .593 .718 .812 .906 .875
9 9.625 .342 .500
10 10.750 .134 .134 .165 .165 .250 .307 .365 .365 .500 .500 .593 .718 .843 1.000 1.125
11 11.750 .375 .500
12 12.750 .156 .165 .180 .180 .250 .330 .375 .406 .562 .500 .687 .843 1.000 1.125 1.312
14 14.000 .156 .188 .250 .312 .375 .375 .437 .593 .500 .750 .937 1.093 1.250 1.406
16 16.000 .165 .188 .250 .312 .375 .375 .500 .656 .500 .843 1.031 1.218 1.437 1.593
18 18.000 .165 .188 .250 .312 .437 .375 .562 .750 .500 .937 1.156 1.375 1.562 1.781
20 20.000 .188 .218 .250 .375 .500 .375 .593 .812 .500 1.031 1.280 1.500 1.750 1.968
24 24.000 .218 .250 .250 .375 .562 .375 .687 .968 .500 1.218 1.531 1.812 2.062 2.343
26 26.000 .312 .500 .375 .500
28 28.000 .312 .500 .625 .375
30 30.000 .250 .312 .312 .500 .625 .375 .500
32 32.000 .312 .500 .625 .375 .688 .500
34 34.000 .312 .500 .625 .375 .688
36 36.000 .312 .625 .375 .750 .500