ASME B16.5
ASTM
ASTM A105 Weld Neck Flange Class 300 Dimensions & Weight Chart (ASME B16.5)
Carbon Steel ASTM A105 / A105N · Class 300 · 1/2" to 24"
Dimensions & weight table
Reference values for layout and freight estimates. Confirm critical dimensions against the latest ASME edition and your project ITP before procurement.
| NPS | DN | OD (mm) | Wall (mm) | Flange OD (mm) | Bolt holes | Weight (kg) |
|---|---|---|---|---|---|---|
| 1/2" | 15 | 21.3 | 2.77 | 95 | 4 | 0.7 |
| 3/4" | 20 | 26.7 | 2.87 | 115 | 4 | 1 |
| 1" | 25 | 33.4 | 3.38 | 125 | 4 | 1.5 |
| 1-1/4" | 32 | 42.2 | 3.56 | 135 | 4 | 1.8 |
| 1-1/2" | 40 | 48.3 | 3.68 | 155 | 4 | 2.2 |
| 2" | 50 | 60.3 | 3.91 | 165 | 8 | 3.6 |
| 2-1/2" | 65 | 73 | 5.16 | 190 | 8 | 5.3 |
| 3" | 80 | 88.9 | 5.49 | 210 | 8 | 6.5 |
| 4" | 100 | 114.3 | 6.02 | 255 | 8 | 10.5 |
| 5" | 125 | 141.3 | 6.55 | 280 | 8 | 13.2 |
| 6" | 150 | 168.3 | 7.11 | 330 | 12 | 17.8 |
| 8" | 200 | 219.1 | 8.18 | 405 | 12 | 29.5 |
| 10" | 250 | 273.1 | 9.27 | 485 | 12 | 43.4 |
| 12" | 300 | 323.9 | 10.31 | 535 | 12 | 65.1 |
| 14" | 350 | 355.6 | 11.13 | 605 | 12 | 80.6 |
| 16" | 400 | 406.4 | 12.7 | 655 | 16 | 105.4 |
| 18" | 450 | 457.2 | 14.27 | 720 | 16 | 127.1 |
| 20" | 500 | 508 | 15.09 | 770 | 16 | 151.9 |
| 24" | 600 | 610 | 17.48 | 825 | 16 | 224.8 |
Material data
Chemical composition
- C
- ≤ 0.35 %
- Mn
- 0.60 – 1.05 %
- P
- ≤ 0.035 %
- S
- ≤ 0.040 %
- Si
- ≤ 0.35 %
Mechanical properties
- Tensile strength
- ≥ 485 MPa (70 ksi)
- Yield strength
- ≥ 250 MPa (36 ksi)
- Elongation
- ≥ 22 % (in 50 mm)
Manufacturing & quality assurance
Yanshan Hengzhenyuan Pipeline — integrated forming, heat treatment, machining and NDT for export utility and EPC programs.
Production capability
- Forged ASTM A105 / A105N bodies for Class 300 service
- CNC machining of hub, bore and RF facing per ASME B16.5
- Higher hub thickness than Class 150 for elevated pressure rating
- Long weld neck and reducing bores from approved drawings
Inspection & release
- OD, PCD, bore and hub length vs B16.5 Class 300 tables
- PMI and hardness survey when ITP requires
- MT on forged surfaces; UT per Section V when specified
- Third-party witness and hydro documentation for packages
Engineering FAQ
Use the piping pressure–temperature rating per ASME B16.5. Class 300 flanges suit higher design pressures within the A105 material group limits.
No. Bolt circle, flange OD, hub dimensions and ratings differ by class. Always match class on the line list.
Many EPC specs require normalized A105N for improved toughness. State grade on the purchase order.
Yes. Heat analysis and mechanical results per batch; PMI retests per ITP when required.
Quick RFQ
Include quantity, delivery port and required certificates. We respond with mill pricing and lead time.