3-1/2 inch (DN 90) pipe dimensions & weight
3-1/2 inch (DN 90) steel pipe has an outside diameter of 101.6 mm (4.000 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 | 97.38 | 5.18 | 3.48 | 5.23 | 7.45 |
| Sch 10S | 3.05 | 0.120 | 95.50 | 7.41 | 4.98 | 7.49 | 7.16 |
| STD | 5.74 | 0.226 | 90.12 | 13.57 | 9.12 | 13.71 | 6.38 |
| Sch 40 | 5.74 | 0.226 | 90.12 | 13.57 | 9.12 | 13.71 | 6.38 |
| XS | 8.08 | 0.318 | 85.44 | 18.63 | 12.52 | 18.82 | 5.73 |
| Sch 80 | 8.08 | 0.318 | 85.44 | 18.63 | 12.52 | 18.82 | 5.73 |
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 3-1/2" flanges and fittings
| Class 150 flange | OD 215 mm · thk 22.3 mm · PCD 177.8 mm · 8 × 5/8" bolts |
| Class 300 flange | OD 230 mm · thk 28.6 mm · PCD 184.2 mm · 8 × 3/4" bolts |
| B16.9 fittings | 90° LR 133 mm · 45° LR 57 mm · 90° SR 89 mm · tee 95 mm · reducer 102 mm · cap 64 mm |
Full tables: Class 150 · Class 300 · B16.9 fittings.
Frequently asked questions
What is the OD of 3-1/2 inch pipe?
3-1/2 inch (DN 90) pipe has an outside diameter of 101.6 mm (4.000 in), regardless of schedule.
What is the wall thickness of 3-1/2 inch Schedule 40 pipe?
5.74 mm (0.226 in), giving an inside diameter of 90.12 mm.
How much does 3-1/2 inch Schedule 40 pipe weigh?
About 13.57 kg/m (9.12 lb/ft) in carbon steel, or 81.4 kg for a 6 m length.
What is the wall thickness of 3-1/2 inch Schedule 80 pipe?
8.08 mm, with an inside diameter of 85.44 mm and weight of 18.63 kg/m.
Last updated 2026-11-02