Gasket Dimensions for Flat Ring and Full Face Applications
ASME B16.21 Class 150
| Nominal Bore | Flat Ring and Full Face Gasket | Flat Ring Gasket | Full Face gasket | Nominal Bore | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inner Diameter | Outer Diameter | Outer Diameter | Bolt Circle Diameter | Diameter of Holes | Number of Bolt Holes | |||||||
| Inches | mm | Inches | mm | Inches | mm | Inches | mm | Inches | mm | |||
| 1/2 | 27/32 | 21.4 | 1 7/8 | 47.6 | 3 1/2 | 88.9 | 2 3/8 | 60.3 | 5/8 | 15.9 | 4 | 1/2 |
| 3/4 | 1 1/16 | 27.0 | 2 1/4 | 57.2 | 3 3/4 | 95.3 | 2 3/4 | 69.9 | 5/8 | 15.9 | 4 | 3/4 |
| 1 | 1 5/16 | 33.3 | 2 5/8 | 66.7 | 4 1/4 | 108.0 | 3 1/8 | 79.4 | 5/8 | 15.9 | 4 | 1 |
| 1 1/4 | 1 21/32 | 42.1 | 3 | 76.2 | 4 5/8 | 117.5 | 3 1/2 | 88.9 | 5/8 | 15.9 | 4 | 1 1/4 |
| 1 1/2 | 1 29/32 | 48.4 | 3 3/8 | 85.7 | 5 | 127.0 | 3 7/8 | 98.4 | 5/8 | 15.9 | 4 | 1 1/2 |
| 2 | 2 3/8 | 60.3 | 4 1/8 | 104.8 | 6 | 152.4 | 4 3/4 | 120.7 | 3/4 | 19.1 | 4 | 2 |
| 2 1/2 | 2 7/8 | 73.0 | 4 7/8 | 123.8 | 7 | 177.8 | 5 1/2 | 139.7 | 3/4 | 19.1 | 4 | 2 1/2 |
| 3 | 3 1/2 | 88.9 | 5 3/8 | 136.5 | 7 1/2 | 190.5 | 6 | 152.4 | 3/4 | 19.1 | 4 | 3 |
| 3 1/2 | 4 | 101.6 | 6 3/8 | 161.9 | 8 1/2 | 215.9 | 7 | 177.8 | 3/4 | 19.1 | 8 | 3 1/2 |
| 4 | 4 1/2 | 114.3 | 6 7/8 | 174.6 | 9 | 228.6 | 7 1/2 | 190.5 | 3/4 | 19.1 | 8 | 4 |
| 5 | 5 9/16 | 141.3 | 7 3/4 | 196.9 | 10 | 254.0 | 8 1/2 | 215.9 | 7/8 | 22.2 | 8 | 5 |
| 6 | 6 5/8 | 168.3 | 8 3/4 | 222.3 | 11 | 279.4 | 9 1/2 | 241.3 | 7/8 | 22.2 | 8 | 6 |
| 8 | 8 5/8 | 219.1 | 11 | 279.4 | 13 1/2 | 342.9 | 11 3/4 | 298.5 | 7/8 | 22.2 | 8 | 8 |
| 10 | 10 3/4 | 273.1 | 13 3/8 | 339.7 | 16 | 406.4 | 14 1/4 | 362.0 | 1 | 25.4 | 12 | 10 |
| 12 | 12 3/4 | 323.9 | 16 1/8 | 409.6 | 19 | 482.6 | 17 | 431.8 | 1 | 25.4 | 12 | 12 |
| 14 | 14 | 355.6 | 17 3/4 | 450.9 | 21 | 533.4 | 18 3/4 | 476.3 | 1 1/8 | 28.6 | 12 | 14 |
| 16 | 16 | 406.4 | 20 1/4 | 514.4 | 23 1/2 | 596.9 | 21 1/4 | 539.8 | 1 1/8 | 28.6 | 16 | 16 |
| 18 | 18 | 457.2 | 21 5/8 | 549.3 | 25 | 635.0 | 22 3/4 | 577.9 | 1 1/4 | 31.8 | 16 | 18 |
| 20 | 20 | 508.0 | 23 7/8 | 606.4 | 27 1/2 | 698.5 | 25 | 635.0 | 1 1/4 | 31.8 | 20 | 20 |
| 24 | 24 | 609.6 | 28 1/4 | 717.6 | 32 | 812.8 | 29 1/2 | 749.3 | 1 3/8 | 34.9 | 20 | 24 |
