ANSI B16.5 Class 900 Blind Flanges
| Nominal Pipe Size | Outside Diameter (O) | Thickness (T) | Raised Face Diameter (R) | Approximate Weight | Bolt Circle (C) | Number of Holes | Diameter of Holes |
|---|---|---|---|---|---|---|---|
| 1/2 | 4.75 mm | 0.88 mm | 1.38 mm | 4 lb | 3.25 mm | 4 | 0.88 mm |
| 3/4 | 5.13 mm | 1.00 mm | 1.69 mm | 6 lb | 3.50 mm | 4 | 0.88 mm |
| 1 | 5.88 mm | 1.13 mm | 2.00 mm | 8 lb | 4.00 mm | 4 | 1.00 mm |
| 1 1/4 | 6.25 mm | 1.13 mm | 2.50 mm | 9 lb | 4.38 mm | 4 | 1.00 mm |
| 1 1/2 | 7.00 mm | 1.25 mm | 2.88 mm | 13 lb | 4.88 mm | 4 | 1.13 mm |
| 2 | 8.50 mm | 1.50 mm | 3.63 mm | 25 lb | 6.50 mm | 8 | 1.00 mm |
| 2 1/2 | 9.63 mm | 1.63 mm | 4.13 mm | 35 lb | 7.50 mm | 8 | 1.13 mm |
| 3 | 9.50 mm | 1.50 mm | 5.00 mm | 29 lb | 7.50 mm | 8 | 1.00 mm |
| 4 | 11.50 mm | 1.75 mm | 6.19 mm | 54 lb | 9.25 mm | 8 | 1.25 mm |
| 5 | 13.75 mm | 2.00 mm | 7.31 mm | 87 lb | 11.00 mm | 8 | 1.38 mm |
| 6 | 15.00 mm | 2.19 mm | 8.50 mm | 115 lb | 12.50 mm | 12 | 1.25 mm |
| 8 | 18.50 mm | 2.50 mm | 10.63 mm | 200 lb | 15.50 mm | 12 | 1.50 mm |
| 10 | 21.50 mm | 2.75 mm | 12.75 mm | 290 lb | 18.50 mm | 16 | 1.50 mm |
| 12 | 24.00 mm | 3.13 mm | 15.00 mm | 415 lb | 21.00 mm | 20 | 1.50 mm |
| 14 | 25.25 mm | 3.38 mm | 16.25 mm | 520 lb | 22.00 mm | 20 | 1.63 mm |
| 16 | 27.75 mm | 3.50 mm | 18.50 mm | 600 lb | 24.25 mm | 20 | 1.75 mm |
| 18 | 31.00 mm | 4.00 mm | 21.00 mm | 850 lb | 27.00 mm | 20 | 2.00 mm |
| 20 | 33.75 mm | 4.25 mm | 23.00 mm | 1075 lb | 29.50 mm | 20 | 2.13 mm |
| 24 | 41.00 mm | 5.50 mm | 27.25 mm | 2025 lb | 35.50 mm | 20 | 2.63 mm |