ANSI B16.5 Class 150 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 | 3.50 mm | 0.44 mm | 1.38 mm | 1 lb | 2.38 mm | 4 | 0.63 mm |
| 3/4 | 3.88 mm | 0.50 mm | 1.69 mm | 2 lb | 2.75 mm | 4 | 0.63 mm |
| 1 | 4.25 mm | 0.56 mm | 2.00 mm | 2 lb | 3.13 mm | 4 | 0.63 mm |
| 1 1/4 | 4.63 mm | 0.63 mm | 2.50 mm | 3 lb | 3.50 mm | 4 | 0.63 mm |
| 1 1/2 | 5.00 mm | 0.69 mm | 2.88 mm | 4 lb | 3.88 mm | 4 | 0.63 mm |
| 2 | 6.00 mm | 0.75 mm | 3.63 mm | 5 lb | 4.75 mm | 4 | 0.75 mm |
| 2 1/2 | 7.00 mm | 0.88 mm | 4.13 mm | 7 lb | 5.50 mm | 4 | 0.75 mm |
| 3 | 7.50 mm | 0.94 mm | 5.00 mm | 9 lb | 6.00 mm | 4 | 0.75 mm |
| 3 1/2 | 8.50 mm | 0.94 mm | 5.50 mm | 13 lb | 7.00 mm | 8 | 0.75 mm |
| 4 | 9.00 mm | 0.94 mm | 6.19 mm | 17 lb | 7.50 mm | 8 | 0.75 mm |
| 5 | 10.00 mm | 0.94 mm | 7.31 mm | 20 lb | 8.50 mm | 8 | 0.88 mm |
| 6 | 11.00 mm | 1.00 mm | 8.50 mm | 26 lb | 9.50 mm | 8 | 0.88 mm |
| 8 | 13.50 mm | 1.13 mm | 10.63 mm | 45 lb | 11.75 mm | 8 | 0.88 mm |
| 10 | 16.00 mm | 1.19 mm | 12.75 mm | 70 lb | 14.25 mm | 12 | 1.00 mm |
| 12 | 19.00 mm | 1.25 mm | 15.00 mm | 110 lb | 17.00 mm | 12 | 1.00 mm |
| 14 | 21.00 mm | 1.38 mm | 16.25 mm | 140 lb | 18.75 mm | 12 | 1.13 mm |
| 16 | 23.50 mm | 1.44 mm | 18.50 mm | 180 lb | 21.25 mm | 16 | 1.13 mm |
| 18 | 25.00 mm | 1.56 mm | 21.00 mm | 220 lb | 22.75 mm | 16 | 1.25 mm |
| 20 | 27.50 mm | 1.69 mm | 23.00 mm | 285 lb | 25.00 mm | 20 | 1.25 mm |
| 22 | 29.50 mm | 1.81 mm | 25.25 mm | 355 lb | 27.25 mm | 20 | 1.38 mm |
| 24 | 32.00 mm | 1.88 mm | 27.25 mm | 430 lb | 29.50 mm | 20 | 1.38 mm |