4 inch pipe dimensions: OD and wall thickness by schedule
Deskely Completions team Singapore
A 4 inch pipe, NPS 4 or DN 100, has an outside diameter of 114.3 mm (4.500 inches) in every schedule. The nominal size is a name, not a measurement: the outside diameter is larger than 4 inch. The schedule sets the wall thickness, and with it the inside diameter and the weight.
The table gives every schedule listed for NPS 4 in ASME B36.10M and B36.19M, in mm and inches.
- Outside diameter: 114.3 mm (4.500 in), the same for every schedule.
- Schedule 40: 6.02 mm wall, 102.3 mm inside diameter.
- Schedule 80: 8.56 mm wall, 97.2 mm inside diameter.
- Metric equivalent: DN 100.
4 inch pipe dimensions by schedule
| Schedule | Wall mm (in) | ID mm (in) | kg/m (lb/ft) |
|---|---|---|---|
| Schedule 5S | 2.11 (0.083) | 110.08 (4.334) | 5.84 (3.92) |
| Schedule 10S | 3.05 (0.120) | 108.20 (4.260) | 8.37 (5.62) |
| STD (standard) | 6.02 (0.237) | 102.26 (4.026) | 16.08 (10.80) |
| Schedule 40 | 6.02 (0.237) | 102.26 (4.026) | 16.08 (10.80) |
| XS (extra strong) | 8.56 (0.337) | 97.18 (3.826) | 22.32 (15.00) |
| Schedule 80 | 8.56 (0.337) | 97.18 (3.826) | 22.32 (15.00) |
| Schedule 120 | 11.13 (0.438) | 92.04 (3.624) | 28.32 (19.03) |
| Schedule 160 | 13.49 (0.531) | 87.32 (3.438) | 33.54 (22.54) |
| XXS (double extra strong) | 17.12 (0.674) | 80.06 (3.152) | 41.03 (27.57) |
Nominal dimensions. Weights are for plain-end carbon steel; stainless steel is about 2 percent heavier. Mill tolerances apply, and your project pipe specification takes precedence.
4 inch pipe outside diameter
The outside diameter of NPS 4 pipe is 114.3 mm, or 4.500 inches, whatever the schedule, so 4 inch fittings and flanges fit every wall thickness. In metric drawings and specifications the same size is called DN 100.
It is larger than 4 inch because, below NPS 14, the nominal size is a traditional name that once roughly matched the bore, not the outside.
Nearby sizes
- 3-1/2 inch pipe dimensions: OD 101.6 mm
- 5 inch pipe dimensions: OD 141.3 mm
Every size and schedule in one table: the pipe schedule chart.
The Deskely products for this
Frequently asked questions
What is the OD of 4 inch pipe?
114.3 mm (4.500 inches), the same for every schedule.
What is the wall thickness of 4 inch schedule 40 pipe?
6.02 mm (0.237 in), giving an inside diameter of 102.3 mm (4.026 in).
What is the wall thickness of 4 inch schedule 80 pipe?
8.56 mm (0.337 in), giving an inside diameter of 97.2 mm (3.826 in).
What is 4 inch pipe in DN?
DN 100.
How much does 4 inch schedule 40 pipe weigh?
16.08 kg/m (10.80 lb/ft) for plain-end carbon steel.
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