PipeData

Standard (STD) Pipe Dimensions

Wall thickness, bore and plain-end weight for all 30 sizes ASME B36.10M publishes in standard (std), NPS 1/8 through NPS 36.

Schedule
Standard (STD)
Sizes published
30 (NPS 1/8 to NPS 36)
Thinnest wall
0.068 in (1.7 mm) at NPS 1/8
Thickest wall
0.375 in (9.5 mm) at NPS 12
Standard
ASME B36.10M

Where standard (std) is used

Standard weight is one of the three weight classes that are older than the schedule numbers. It is still the commonest way to call up ordinary carbon steel pipe, above all in the large sizes, where it means a single fixed wall.

Pipe wall thickness to scale, Standard (STD)Pipe cross-sections drawn to scale at the same outside diameter so the wall thicknesses can be compared. NPS 1/8: 0.068 in wall on 0.405 in OD; NPS 8: 0.322 in wall on 8.625 in OD; NPS 36: 0.375 in wall on 36.000 in ODNPS 1/80.068 in wall on 0.405 in ODNPS 80.322 in wall on 8.625 in ODNPS 360.375 in wall on 36.000 in OD
Standard (STD) in three sizes, each drawn to its own scale. The sections are drawn at the same width so that the wall can be compared with the diameter it belongs to. The wall gets thicker as the size goes up, but it takes up a smaller share of the pipe.

Standard (STD) in every size

Dimensions are given in inches, with the millimetre equivalent beneath in grey.

ASME B36.10M standard (std) dimensions.
SizeDNOutside diameterWall thicknessInside diameterWeight, emptyWater (US gal/ft)This size
NPS 1/8DN 60.40510.29 mm0.0681.73 mm0.2696.83 mm0.240.36 kg/m0.003all schedules →
NPS 1/4DN 80.54013.72 mm0.0882.24 mm0.3649.25 mm0.430.63 kg/m0.005all schedules →
NPS 3/8DN 100.67517.14 mm0.0912.31 mm0.49312.52 mm0.570.85 kg/m0.010all schedules →
NPS 1/2DN 150.84021.34 mm0.1092.77 mm0.62215.80 mm0.851.27 kg/m0.016all schedules →
NPS 3/4DN 201.05026.67 mm0.1132.87 mm0.82420.93 mm1.131.68 kg/m0.028all schedules →
NPS 1DN 251.31533.40 mm0.1333.38 mm1.04926.64 mm1.682.50 kg/m0.045all schedules →
NPS 1 1/4DN 321.66042.16 mm0.1403.56 mm1.38035.05 mm2.273.39 kg/m0.078all schedules →
NPS 1 1/2DN 401.90048.26 mm0.1453.68 mm1.61040.89 mm2.724.05 kg/m0.106all schedules →
NPS 2DN 502.37560.32 mm0.1543.91 mm2.06752.50 mm3.665.44 kg/m0.174all schedules →
NPS 2 1/2DN 652.87573.02 mm0.2035.16 mm2.46962.71 mm5.808.63 kg/m0.249all schedules →
NPS 3DN 803.50088.90 mm0.2165.49 mm3.06877.93 mm7.5811.28 kg/m0.384all schedules →
NPS 3 1/2DN 904.000101.60 mm0.2265.74 mm3.54890.12 mm9.1213.57 kg/m0.514all schedules →
NPS 4DN 1004.500114.30 mm0.2376.02 mm4.026102.26 mm10.8016.07 kg/m0.661all schedules →
NPS 5DN 1255.563141.30 mm0.2586.55 mm5.047128.19 mm14.6321.77 kg/m1.039all schedules →
NPS 6DN 1506.625168.27 mm0.2807.11 mm6.065154.05 mm18.9928.26 kg/m1.501all schedules →
NPS 8DN 2008.625219.07 mm0.3228.18 mm7.981202.72 mm28.5842.53 kg/m2.599all schedules →
NPS 10DN 25010.750273.05 mm0.3659.27 mm10.020254.51 mm40.5260.30 kg/m4.096all schedules →
NPS 12DN 30012.750323.85 mm0.3759.52 mm12.000304.80 mm49.6173.83 kg/m5.875all schedules →
NPS 14DN 35014.000355.60 mm0.3759.52 mm13.250336.55 mm54.6281.28 kg/m7.163all schedules →
NPS 16DN 40016.000406.40 mm0.3759.52 mm15.250387.35 mm62.6493.21 kg/m9.489all schedules →
NPS 18DN 45018.000457.20 mm0.3759.52 mm17.250438.15 mm70.65105.14 kg/m12.141all schedules →
NPS 20DN 50020.000508.00 mm0.3759.52 mm19.250488.95 mm78.67117.08 kg/m15.119all schedules →
NPS 22DN 55022.000558.80 mm0.3759.52 mm21.250539.75 mm86.69129.01 kg/m18.424all schedules →
NPS 24DN 60024.000609.60 mm0.3759.52 mm23.250590.55 mm94.71140.94 kg/m22.055all schedules →
NPS 26DN 65026.000660.40 mm0.3759.52 mm25.250641.35 mm102.72152.87 kg/m26.012all schedules →
NPS 28DN 70028.000711.20 mm0.3759.52 mm27.250692.15 mm110.74164.80 kg/m30.296all schedules →
NPS 30DN 75030.000762.00 mm0.3759.52 mm29.250742.95 mm118.76176.73 kg/m34.907all schedules →
NPS 32DN 80032.000812.80 mm0.3759.52 mm31.250793.75 mm126.78188.66 kg/m39.844all schedules →
NPS 34DN 85034.000863.60 mm0.3759.52 mm33.250844.55 mm134.79200.60 kg/m45.107all schedules →
NPS 36DN 90036.000914.40 mm0.3759.52 mm35.250895.35 mm142.81212.53 kg/m50.696all schedules →

Weight is plain-end carbon steel, w = 10.69 × t × (OD − t) lb/ft.

How the wall changes with size

The wall in standard (std) is 0.068 in (1.7 mm) at NPS 1/8 and 0.375 in (9.5 mm) at NPS 36. Measured against the pipe it belongs to, that is 16.8% of the outside diameter at the small end and 1.0% at the large end, so the wall does not keep pace with the diameter. The pressure the pipe will hold moves the same way. On the basis used throughout this site (ASME B31.3, S = 20,000 psi, nominal wall, no corrosion allowance) standard (std) holds about 7,496 psig at NPS 1/4 and about 420 psig at NPS 36. A schedule is therefore chosen size by size, from a calculation, and not once for a whole plant.

From NPS 12 up to NPS 36 the wall is the same in every size, 0.375 in (9.5 mm). Over that range standard (std) is a fixed thickness and no longer a series that climbs with the size.

Guides and comparisons for this page

STD vs XSWhere the weight classes match the numbered schedules.What a pipe schedule actually isWhy a schedule is a wall series and not a thickness.Pipe wall thickness calculationBarlow and ASME B31.3, corrosion allowance and mill tolerance.Pipe sizing by flow rate and velocityTurn a flow rate into a line size using velocity limits.

Common questions

What sizes is standard (std) pipe made in?

ASME B36.10M publishes standard (std) in 30 sizes, from NPS 1/8 through NPS 36. Wall thickness runs from 0.068 in (1.7 mm) at the small end to 0.375 in (9.5 mm) at the large end.

Does standard (std) mean the same wall thickness in every size?

No. It is a series, not a thickness. The wall is 0.068 in (1.7 mm) at NPS 1/8 and 0.375 in (9.5 mm) at NPS 36, so the thickness always has to be read off the table for the size in hand.

How pipe schedules work →