ASME B36.10M (welded and seamless wrought steel pipe) · DN 100
Outside diameter 4.500" (114.30 mm), wall 0.674" (17.12 mm), inside diameter 3.152" (80.06 mm), 27.57 lb per foot.
| Trade size | NPS 4 · DN 100 |
|---|---|
| Schedule | Double extra strong (XXS) |
| Standard | ASME B36.10M (welded and seamless wrought steel pipe) |
| Outside diameter | 4.500" · 114.30 mm |
| Wall thickness | 0.674" · 17.12 mm |
| Inside diameter | 3.152" · 80.06 mm |
| Weight, plain end | 27.57 lb/ft · 41.03 kg/m |
Cross-check: the standard plain-end weight formula W = 10.6802 x t x (OD - t) gives 27.54 lb/ft here, 0.1% from the published 27.57 lb/ft. The published figure is the one printed above.
NPS 4 double extra strong (xxs) pipe measures 4.500 in (114.30 mm) across the outside with a 0.674 in wall, so the bore is 3.152 in (80.06 mm). That bore gives a flow area of 7.803 in² and holds 0.4054 US gallons per foot (5.034 litres per metre). The outside diameter is 6.7 times the wall, and the steel itself has a cross-section of 8.101 in² and weighs 27.57 lb per foot plain end. One trade size up, NPS 5 in the same schedule carries 1.66 times the flow area.
Schedule 160 is the next lighter wall at NPS 4: 0.531 in, 0.143 in thinner, which opens the bore to 3.438 in and adds 19% to the flow area, for 18% less weight per foot.
Next trade size up in this schedule: NPS 5 double extra strong (xxs), bore 4.063 in.
| Flow area | 7.803 in² |
|---|---|
| Capacity | 0.4054 US gal/ft · 5.034 L/m |
| Metal area | 8.101 in² |
| Moment of inertia | 15.28 in⁴ |
| Section modulus | 6.793 in³ |
| Radius of gyration | 1.374 in |
| Outside surface | 1.178 ft² per foot |
Plain geometry of a hollow circle with OD = 4.500 in and ID = 3.152 in: flow area π/4·ID², metal area π/4·(OD² − ID²), moment of inertia π/64·(OD⁴ − ID⁴), section modulus I ÷ (OD/2), radius of gyration √(I ÷ metal area), capacity flow area × 12 ÷ 231 (231 in³ to the US gallon). Nominal dimensions, so mill tolerance and corrosion allowance are not included.
Nominal Pipe Size is a label, not a measurement. NPS 4 pipe has an outside diameter of 4.500 inches, and it keeps that outside diameter in every schedule made. What the schedule number changes is the wall: at double extra strong (xxs) the wall is 0.674 inches, so the bore comes out at 3.152 inches.
That is the practical consequence. Fittings, flanges, supports and threading dies are sized to the outside diameter, so they fit any schedule of the same trade size. Flow, pressure drop and anything that has to pass through the pipe depend on the inside diameter, which changes with every schedule. Order by trade size and schedule; work your hydraulics from the bore.
Same outside diameter of 4.500 inches throughout - only the wall and the bore move.
| Schedule | Wall (in) | ID (in) | Weight (lb/ft) |
|---|---|---|---|
| Schedule 5 · 5S | 0.083 | 4.334 | 3.92 |
| Schedule 10 · 10S | 0.120 | 4.260 | 5.62 |
| Schedule 30 | 0.188 | 4.124 | 8.67 |
| Schedule 40 · STD, 40S | 0.237 | 4.026 | 10.80 |
| Schedule 80 · XS, 80S | 0.337 | 3.826 | 14.98 |
| Schedule 120 | 0.438 | 3.624 | 19.02 |
| Schedule 160 | 0.531 | 3.438 | 22.53 |
0.674 inches (17.12 mm). The outside diameter is 4.500 inches (114.30 mm) whatever the schedule, so this wall leaves an inside diameter of 3.152 inches.
3.152 inches (80.06 mm). Inside diameter is outside diameter minus twice the wall: 4.500 - 2 x 0.674 = 3.152 inches.
No. NPS 4 is a trade size, not a measurement. The pipe measures 4.500 inches across the outside and 3.152 inches across the bore in this schedule. Only the outside diameter is fixed across schedules.
27.57 pounds per foot plain end (41.03 kg per metre), for carbon steel. The figure excludes coatings, linings and fittings.
This table runs from NPS 1/8 to NPS 24 and stops there. ASME B36.10M itself continues to NPS 80; those larger sizes are not carried here, so a size above NPS 24 is missing rather than undefined.
Dimensions are as defined by ASME B36.10M (welded and seamless wrought steel pipe). This site is an independent reference and is not affiliated with, endorsed by or approved by any standards body.
Every value on this page was cross-checked against 5 independent published sources:
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