2-1/2 inch pipe dimensions: OD and wall thickness by schedule
Deskely Completions team Singapore
A 2-1/2 inch pipe, NPS 2-1/2 or DN 65, has an outside diameter of 73 mm (2.875 inches) in every schedule. The nominal size is a name, not a measurement: the outside diameter is larger than 2-1/2 inch. The schedule sets the wall thickness, and with it the inside diameter and the weight.
The table gives every schedule listed for NPS 2-1/2 in ASME B36.10M and B36.19M, in mm and inches.
- Outside diameter: 73 mm (2.875 in), the same for every schedule.
- Schedule 40: 5.16 mm wall, 62.7 mm inside diameter.
- Schedule 80: 7.01 mm wall, 59.0 mm inside diameter.
- Metric equivalent: DN 65.
2-1/2 inch pipe dimensions by schedule
| Schedule | Wall mm (in) | ID mm (in) | kg/m (lb/ft) |
|---|---|---|---|
| Schedule 5S | 2.11 (0.083) | 68.78 (2.708) | 3.69 (2.48) |
| Schedule 10S | 3.05 (0.120) | 66.90 (2.634) | 5.26 (3.54) |
| STD (standard) | 5.16 (0.203) | 62.68 (2.468) | 8.63 (5.80) |
| Schedule 40 | 5.16 (0.203) | 62.68 (2.468) | 8.63 (5.80) |
| XS (extra strong) | 7.01 (0.276) | 58.98 (2.322) | 11.41 (7.67) |
| Schedule 80 | 7.01 (0.276) | 58.98 (2.322) | 11.41 (7.67) |
| Schedule 160 | 9.53 (0.375) | 53.94 (2.124) | 14.92 (10.02) |
| XXS (double extra strong) | 14.02 (0.552) | 44.96 (1.770) | 20.39 (13.70) |
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.
2-1/2 inch pipe outside diameter
The outside diameter of NPS 2-1/2 pipe is 73 mm, or 2.875 inches, whatever the schedule, so 2-1/2 inch fittings and flanges fit every wall thickness. In metric drawings and specifications the same size is called DN 65.
It is larger than 2-1/2 inch because, below NPS 14, the nominal size is a traditional name that once roughly matched the bore, not the outside.
Nearby sizes
- 2 inch pipe dimensions: OD 60.3 mm
- 3 inch pipe dimensions: OD 88.9 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 2-1/2 inch pipe?
73 mm (2.875 inches), the same for every schedule.
What is the wall thickness of 2-1/2 inch schedule 40 pipe?
5.16 mm (0.203 in), giving an inside diameter of 62.7 mm (2.468 in).
What is the wall thickness of 2-1/2 inch schedule 80 pipe?
7.01 mm (0.276 in), giving an inside diameter of 59.0 mm (2.322 in).
What is 2-1/2 inch pipe in DN?
DN 65.
How much does 2-1/2 inch schedule 40 pipe weigh?
8.63 kg/m (5.80 lb/ft) for plain-end carbon steel.
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