Industry Standard Class 350 Blind Flanges
| Nominal Pipe Size | Outside Diameter (O) | Thickness (T) | Raised Face Diameter (R) | Approximate Weight | Bolt Circle (C) | Number of Holes | Diameter of Bolt Holes |
|---|---|---|---|---|---|---|---|
| 26 | 32.75 mm | 2.75 mm | 29.50 mm | 580 lb | 30.63 mm | 28 | 1.13 mm |
| 28 | 34.75 mm | 2.88 mm | 31.50 mm | 750 lb | 32.63 mm | 28 | 1.13 mm |
| 30 | 37.00 mm | 3.00 mm | 33.75 mm | 890 lb | 34.88 mm | 32 | 1.13 mm |
| 32 | 39.00 mm | 3.25 mm | 35.75 mm | 1050 lb | 36.88 mm | 36 | 1.13 mm |
| 34 | 41.00 mm | 3.38 mm | 37.75 mm | 1225 lb | 38.88 mm | 40 | 1.13 mm |
| 36 | 43.75 mm | 3.63 mm | 40.25 mm | 1500 lb | 41.50 mm | 40 | 1.25 mm |
| 38 | 45.75 mm | 3.75 mm | 42.25 mm | 1700 lb | 43.50 mm | 40 | 1.25 mm |
| 40 | 47.75 mm | 4.00 mm | 44.25 mm | 1975 lb | 45.50 mm | 44 | 1.25 mm |
| 42 | 50.00 mm | 4.13 mm | 46.50 mm | 2225 lb | 47.75 mm | 48 | 1.25 mm |
| 44 | 52.75 mm | 4.38 mm | 48.88 mm | 2625 lb | 50.25 mm | 44 | 1.38 mm |
| 46 | 54.75 mm | 4.75 mm | 50.88 mm | 2950 lb | 52.25 mm | 48 | 1.38 mm |
| 48 | 56.75 mm | 4.75 mm | 52.88 mm | 3300 lb | 54.25 mm | 48 | 1.38 mm |