ANSI B16.5 Class 300 Lap Joint Flanges
| Nominal Pipe Size | Outside Diameter (O) | Thickness (T) | Length Thru Hub (Y) | Hub Diameter (X) | Radius (r) | Bore (B) | Approximate Weight | Bolt Circle (C) | Number of Holes | Diameter of Holes |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.75 mm | 0.56 mm | 0.88 mm | 1.50 mm | 0.13 mm | 0.90 mm | 2 lb | 2.63 mm | 4 | 0.63 mm |
| 3/4 | 4.63 mm | 0.63 mm | 1.00 mm | 1.88 mm | 0.13 mm | 1.11 mm | 3 lb | 3.25 mm | 4 | 0.75 mm |
| 1 | 4.88 mm | 0.69 mm | 1.06 mm | 2.13 mm | 0.13 mm | 1.38 mm | 3 lb | 3.50 mm | 4 | 0.75 mm |
| 1 1/4 | 5.25 mm | 0.75 mm | 1.06 mm | 2.50 mm | 0.19 mm | 1.72 mm | 4 lb | 3.88 mm | 4 | 0.75 mm |
| 1 1/2 | 6.13 mm | 0.81 mm | 1.19 mm | 2.75 mm | 0.25 mm | 1.97 mm | 6 lb | 4.50 mm | 4 | 0.88 mm |
| 2 | 6.50 mm | 0.88 mm | 1.31 mm | 3.31 mm | 0.31 mm | 2.46 mm | 7 lb | 5.00 mm | 8 | 0.75 mm |
| 2 1/2 | 7.50 mm | 1.00 mm | 1.50 mm | 3.94 mm | 0.31 mm | 2.97 mm | 10 lb | 5.88 mm | 8 | 0.88 mm |
| 3 | 8.25 mm | 1.13 mm | 1.69 mm | 4.63 mm | 0.38 mm | 3.60 mm | 13 lb | 6.63 mm | 8 | 0.88 mm |
| 3 1/2 | 9.00 mm | 1.19 mm | 1.75 mm | 5.25 mm | 0.38 mm | 4.10 mm | 17 lb | 7.25 mm | 8 | 0.88 mm |
| 4 | 10.00 mm | 1.25 mm | 1.88 mm | 5.75 mm | 0.44 mm | 4.60 mm | 22 lb | 7.88 mm | 8 | 0.88 mm |
| 5 | 11.00 mm | 1.38 mm | 2.00 mm | 7.00 mm | 0.44 mm | 5.69 mm | 28 lb | 9.25 mm | 8 | 0.88 mm |
| 6 | 12.50 mm | 1.44 mm | 2.06 mm | 8.13 mm | 0.50 mm | 6.75 mm | 39 lb | 10.63 mm | 12 | 0.88 mm |
| 8 | 15.00 mm | 1.63 mm | 2.44 mm | 10.25 mm | 0.50 mm | 8.75 mm | 58 lb | 13.00 mm | 12 | 1.00 mm |
| 10 | 17.50 mm | 1.88 mm | 3.75 mm | 12.63 mm | 0.50 mm | 10.92 mm | 91 lb | 15.25 mm | 16 | 1.13 mm |
| 12 | 20.50 mm | 2.00 mm | 4.00 mm | 14.75 mm | 0.50 mm | 12.92 mm | 140 lb | 17.75 mm | 16 | 1.25 mm |
| 14 | 23.00 mm | 2.13 mm | 4.38 mm | 16.75 mm | 0.50 mm | 14.18 mm | 190 lb | 20.25 mm | 20 | 1.25 mm |
| 16 | 25.50 mm | 2.25 mm | 4.75 mm | 19.00 mm | 0.50 mm | 16.19 mm | 250 lb | 22.50 mm | 20 | 1.38 mm |
| 18 | 28.00 mm | 2.38 mm | 5.13 mm | 21.00 mm | 0.50 mm | 18.20 mm | 295 lb | 24.75 mm | 24 | 1.38 mm |
| 20 | 30.50 mm | 2.50 mm | 5.50 mm | 23.13 mm | 0.50 mm | 20.25 mm | 370 lb | 27.00 mm | 24 | 1.38 mm |
| 22 | 33.00 mm | 2.63 mm | 5.75 mm | 25.25 mm | 0.50 mm | 22.25 mm | 435 lb | 29.25 mm | 24 | 1.63 mm |
| 24 | 36.00 mm | 2.75 mm | 6.00 mm | 27.63 mm | 0.50 mm | 24.25 mm | 550 lb | 32.00 mm | 24 | 1.63 mm |