3/4 inch (DN 20) pipe dimensions & weight
3/4 inch (DN 20) steel pipe has an outside diameter of 26.7 mm (1.051 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 | 1.65 | 0.065 | 23.40 | 1.02 | 0.69 | 1.03 | 0.43 |
| Sch 10S | 2.11 | 0.083 | 22.48 | 1.28 | 0.86 | 1.29 | 0.40 |
| STD | 2.87 | 0.113 | 20.96 | 1.69 | 1.14 | 1.71 | 0.35 |
| Sch 40 | 2.87 | 0.113 | 20.96 | 1.69 | 1.14 | 1.71 | 0.35 |
| XS | 3.91 | 0.154 | 18.88 | 2.20 | 1.48 | 2.22 | 0.28 |
| Sch 80 | 3.91 | 0.154 | 18.88 | 2.20 | 1.48 | 2.22 | 0.28 |
| Sch 160 | 5.56 | 0.219 | 15.58 | 2.90 | 1.95 | 2.93 | 0.19 |
| XXS | 7.82 | 0.308 | 11.06 | 3.64 | 2.45 | 3.68 | 0.10 |
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 3/4" flanges and fittings
| Class 150 flange | OD 100 mm · thk 11.2 mm · PCD 69.9 mm · 4 × 1/2" bolts |
| Class 300 flange | OD 115 mm · thk 14.3 mm · PCD 82.6 mm · 4 × 5/8" bolts |
| B16.9 fittings | 90° LR 29 mm · 45° LR 11 mm · tee 29 mm · reducer 38 mm · cap 25 mm |
Full tables: Class 150 · Class 300 · B16.9 fittings.
Frequently asked questions
What is the OD of 3/4 inch pipe?
3/4 inch (DN 20) pipe has an outside diameter of 26.7 mm (1.051 in), regardless of schedule.
What is the wall thickness of 3/4 inch Schedule 40 pipe?
2.87 mm (0.113 in), giving an inside diameter of 20.96 mm.
How much does 3/4 inch Schedule 40 pipe weigh?
About 1.69 kg/m (1.14 lb/ft) in carbon steel, or 10.1 kg for a 6 m length.
What is the wall thickness of 3/4 inch Schedule 80 pipe?
3.91 mm, with an inside diameter of 18.88 mm and weight of 2.20 kg/m.
Last updated 2026-11-02