2-1/2 inch (DN 65) pipe dimensions & weight
2-1/2 inch (DN 65) steel pipe has an outside diameter of 73.0 mm (2.874 in) in every schedule. Below: wall thickness, inside diameter, weight per metre and water capacity for each ASME B36.10M / B36.19M schedule.
| Schedule | Wall (mm) | Wall (in) | ID (mm) | CS kg/m | CS lb/ft | SS 304 kg/m | Water L/m |
|---|---|---|---|---|---|---|---|
| Sch 5S | 2.11 | 0.083 | 68.78 | 3.69 | 2.48 | 3.73 | 3.72 |
| Sch 10S | 3.05 | 0.120 | 66.90 | 5.26 | 3.53 | 5.31 | 3.52 |
| STD | 5.16 | 0.203 | 62.68 | 8.63 | 5.80 | 8.72 | 3.09 |
| Sch 40 | 5.16 | 0.203 | 62.68 | 8.63 | 5.80 | 8.72 | 3.09 |
| XS | 7.01 | 0.276 | 58.98 | 11.41 | 7.67 | 11.53 | 2.73 |
| Sch 80 | 7.01 | 0.276 | 58.98 | 11.41 | 7.67 | 11.53 | 2.73 |
| Sch 160 | 9.53 | 0.375 | 53.94 | 14.92 | 10.03 | 15.07 | 2.29 |
| XXS | 14.02 | 0.552 | 44.96 | 20.39 | 13.70 | 20.60 | 1.59 |
CS = carbon steel (7.85 g/cm³). SS 304 at 7.93 g/cm³; for 316 multiply CS weight by 1.017. Water capacity = internal volume per metre.
Matching 2-1/2" flanges and fittings
| Class 150 flange | OD 180 mm · thk 20.7 mm · PCD 139.7 mm · 4 × 5/8" bolts |
| Class 300 flange | OD 190 mm · thk 23.9 mm · PCD 149.2 mm · 8 × 3/4" bolts |
| B16.9 fittings | 90° LR 95 mm · 45° LR 44 mm · 90° SR 64 mm · tee 76 mm · reducer 89 mm · cap 38 mm |
Full tables: Class 150 · Class 300 · B16.9 fittings.
Frequently asked questions
What is the OD of 2-1/2 inch pipe?
2-1/2 inch (DN 65) pipe has an outside diameter of 73.0 mm (2.874 in), regardless of 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 62.68 mm.
How much does 2-1/2 inch Schedule 40 pipe weigh?
About 8.63 kg/m (5.80 lb/ft) in carbon steel, or 51.8 kg for a 6 m length.
What is the wall thickness of 2-1/2 inch Schedule 80 pipe?
7.01 mm, with an inside diameter of 58.98 mm and weight of 11.41 kg/m.
Last updated 2026-11-02