PipeData

Extra Strong (XS) Pipe Dimensions

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

Schedule
Extra Strong (XS)
Sizes published
30 (NPS 1/8 to NPS 36)
Thinnest wall
0.095 in (2.4 mm) at NPS 1/8
Thickest wall
0.500 in (12.7 mm) at NPS 8
Standard
ASME B36.10M

Where extra strong (xs) is used

Extra strong is the heavy one of the three old weight classes. It is used much as Schedule 80 is, and in the large sizes it means a single fixed wall.

Pipe wall thickness to scale, Extra Strong (XS)Pipe cross-sections drawn to scale at the same outside diameter so the wall thicknesses can be compared. NPS 1/8: 0.095 in wall on 0.405 in OD; NPS 8: 0.500 in wall on 8.625 in OD; NPS 36: 0.500 in wall on 36.000 in ODNPS 1/80.095 in wall on 0.405 in ODNPS 80.500 in wall on 8.625 in ODNPS 360.500 in wall on 36.000 in OD
Extra Strong (XS) 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.

Extra Strong (XS) in every size

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

ASME B36.10M extra strong (xs) dimensions.
SizeDNOutside diameterWall thicknessInside diameterWeight, emptyWater (US gal/ft)This size
NPS 1/8DN 60.40510.29 mm0.0952.41 mm0.2155.46 mm0.310.47 kg/m0.002all schedules →
NPS 1/4DN 80.54013.72 mm0.1193.02 mm0.3027.67 mm0.540.80 kg/m0.004all schedules →
NPS 3/8DN 100.67517.14 mm0.1263.20 mm0.42310.74 mm0.741.10 kg/m0.007all schedules →
NPS 1/2DN 150.84021.34 mm0.1473.73 mm0.54613.87 mm1.091.62 kg/m0.012all schedules →
NPS 3/4DN 201.05026.67 mm0.1543.91 mm0.74218.85 mm1.482.20 kg/m0.022all schedules →
NPS 1DN 251.31533.40 mm0.1794.55 mm0.95724.31 mm2.173.23 kg/m0.037all schedules →
NPS 1 1/4DN 321.66042.16 mm0.1914.85 mm1.27832.46 mm3.004.46 kg/m0.067all schedules →
NPS 1 1/2DN 401.90048.26 mm0.2005.08 mm1.50038.10 mm3.635.41 kg/m0.092all schedules →
NPS 2DN 502.37560.32 mm0.2185.54 mm1.93949.25 mm5.037.48 kg/m0.153all schedules →
NPS 2 1/2DN 652.87573.02 mm0.2767.01 mm2.32359.00 mm7.6711.41 kg/m0.220all schedules →
NPS 3DN 803.50088.90 mm0.3007.62 mm2.90073.66 mm10.2615.27 kg/m0.343all schedules →
NPS 3 1/2DN 904.000101.60 mm0.3188.08 mm3.36485.45 mm12.5218.63 kg/m0.462all schedules →
NPS 4DN 1004.500114.30 mm0.3378.56 mm3.82697.18 mm15.0022.32 kg/m0.597all schedules →
NPS 5DN 1255.563141.30 mm0.3759.52 mm4.813122.25 mm20.8030.95 kg/m0.945all schedules →
NPS 6DN 1506.625168.27 mm0.43210.97 mm5.761146.33 mm28.6042.56 kg/m1.354all schedules →
NPS 8DN 2008.625219.07 mm0.50012.70 mm7.625193.67 mm43.4364.63 kg/m2.372all schedules →
NPS 10DN 25010.750273.05 mm0.50012.70 mm9.750247.65 mm54.7981.53 kg/m3.879all schedules →
NPS 12DN 30012.750323.85 mm0.50012.70 mm11.750298.45 mm65.4897.44 kg/m5.633all schedules →
NPS 14DN 35014.000355.60 mm0.50012.70 mm13.000330.20 mm72.16107.38 kg/m6.895all schedules →
NPS 16DN 40016.000406.40 mm0.50012.70 mm15.000381.00 mm82.85123.29 kg/m9.180all schedules →
NPS 18DN 45018.000457.20 mm0.50012.70 mm17.000431.80 mm93.54139.20 kg/m11.791all schedules →
NPS 20DN 50020.000508.00 mm0.50012.70 mm19.000482.60 mm104.23155.11 kg/m14.729all schedules →
NPS 22DN 55022.000558.80 mm0.50012.70 mm21.000533.40 mm114.92171.02 kg/m17.993all schedules →
NPS 24DN 60024.000609.60 mm0.50012.70 mm23.000584.20 mm125.61186.92 kg/m21.583all schedules →
NPS 26DN 65026.000660.40 mm0.50012.70 mm25.000635.00 mm136.30202.83 kg/m25.500all schedules →
NPS 28DN 70028.000711.20 mm0.50012.70 mm27.000685.80 mm146.99218.74 kg/m29.743all schedules →
NPS 30DN 75030.000762.00 mm0.50012.70 mm29.000736.60 mm157.68234.65 kg/m34.313all schedules →
NPS 32DN 80032.000812.80 mm0.50012.70 mm31.000787.40 mm168.37250.56 kg/m39.209all schedules →
NPS 34DN 85034.000863.60 mm0.50012.70 mm33.000838.20 mm179.06266.47 kg/m44.431all schedules →
NPS 36DN 90036.000914.40 mm0.50012.70 mm35.000889.00 mm189.75282.37 kg/m49.980all schedules →

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

How the wall changes with size

The wall in extra strong (xs) is 0.095 in (2.4 mm) at NPS 1/8 and 0.500 in (12.7 mm) at NPS 36. Measured against the pipe it belongs to, that is 23.5% of the outside diameter at the small end and 1.4% 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) extra strong (xs) holds about 6,647 psig at NPS 3/4 and about 562 psig at NPS 36. A schedule is therefore chosen size by size, from a calculation, and not once for a whole plant.

From NPS 8 up to NPS 36 the wall is the same in every size, 0.500 in (12.7 mm). Over that range extra strong (xs) 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.XS vs XXSExtra strong against double extra strong.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 extra strong (xs) pipe made in?

ASME B36.10M publishes extra strong (xs) in 30 sizes, from NPS 1/8 through NPS 36. Wall thickness runs from 0.095 in (2.4 mm) at the small end to 0.500 in (12.7 mm) at the large end.

Does extra strong (xs) mean the same wall thickness in every size?

No. It is a series, not a thickness. The wall is 0.095 in (2.4 mm) at NPS 1/8 and 0.500 in (12.7 mm) at NPS 36, so the thickness always has to be read off the table for the size in hand.

How pipe schedules work →