12 inch ASME B16.5 Class 300 Flange Dimensions
12 inch (DN 300) to ASME B16.5: OD 520 mm; thickness 49.3 mm; raised face 381.0 mm; hub 375 mm; pipe OD 323.8 mm.
Key to dimensions
- O
- Outside diameter of flange
- tf
- Minimum flange thickness (also the blind flange thickness), excluding the raised face
- R
- Diameter of raised face
- X
- Hub diameter at base
- A
- Hub diameter at the welding end of a weld neck flange (pipe outside diameter)
- Y
- Length through hub — given separately for weld neck, slip-on / threaded / socket weld and lap joint flanges
- W
- Bolt circle diameter
- Holes
- Number and diameter of bolt holes
- Bolt
- Nominal bolt diameter in inches
12 inch ASME B16.5 Class 300 Flange Dimensions — all dimensions
Class 300 flange dimensions (mm)
| Dimension | Value | Equivalent |
|---|---|---|
| DN | 300 | |
| Outside dia — O | 520 mm | 20.47 in |
| Min thickness — tf | 49.3 mm | 1.94 in |
| Raised face dia — R | 381.0 mm | 15.00 in |
| Hub dia — X | 375 mm | 14.76 in |
| Hub at weld — A | 323.8 mm | 12.75 in |
| Weld neck — Y | 129 mm | 5.08 in |
| Slip-on / Thr / SW — Y | 71 mm | 2.80 in |
| Lap joint — Y | 102 mm | 4.02 in |
| Bolt circle — W | 450.8 mm | 17.75 in |
| Number of holes | 16 | |
| Hole dia | 31.8 mm | 1.25 in |
| Bolt size | 1⅛" |
Class 300 bolting and approximate weights
| Dimension | Value | Equivalent |
|---|---|---|
| Number of studs | 16 | |
| Stud dia | 1⅛" | |
| Stud length — Raised face | 170 mm | 6.69 in |
| Stud length — Ring joint | 185 mm | 7.28 in |
| Weld neck — kg, approx. | 64.4 kg | 142.0 lb |
| Slip-on — kg, approx. | 51.3 kg | 113.1 lb |
| Blind — kg, approx. | 78.9 kg | 173.9 lb |
Values are nominal, from ASME B16.5 Class 300 Flange Dimensions. Verify critical dimensions against the current edition of the standard before design, purchase or fabrication.
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12 inch ASME B16.5 Class 300 Flange Dimensions: common questions
What are the 12 inch ASME B16.5 Class 300 Flange Dimensions?
12 inch (DN 300) to ASME B16.5: OD 520 mm; thickness 49.3 mm; raised face 381.0 mm; hub 375 mm; pipe OD 323.8 mm.
Does Teshi Group manufacture 12 inch flanges?
Yes. Teshi Group is an OEM manufacturer in India of flanges to ASME B16.5, in carbon, alloy, stainless, duplex, super duplex, nickel alloys, titanium and Cu-Ni, with EN 10204 3.1 certificates.
Can I download the 12 inch dimensions as a PDF?
Yes. Use “Download PDF for this size” on this page to get a single-size, print-ready PDF with the drawing and every tabulated dimension, or download the full ASME B16.5 Class 300 Flange Dimensions chart.
Need 12 inch flanges?
Teshi Group manufactures them in India — send your size, rating and material and get a quote in 24–48 hours.
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