Carbon and Stainless Steel Flanges - ASME/ANSI Class 900
ASME/ANSI B16.5-1996 Pipe Flanges and Flanged Fittings - Class 900 Flanges - outside and inside diameters, bolt circles, numbers and diameters of bolts.
ASME/ANSI B16.5-1996 Pipe Flanges and Flanged Fittings - Class 900 Flanges - outside and inside diameters, bolt circles, numbers and diameters of bolts for Weld neck, Threaded, Slip-on, Lap joint, Socket weld and Blind flanges.
Carbon and stainless steel qualities according ASME B16.5 Table 1A.
| Pipe Size (inches) | Flange Outside Diameter (inches) | Pipe Outside Diameter (inches) | Number of Bolt Holes | Bolt Hole Diameter (inches) 1) | Bolt Circle (inches) |
|---|---|---|---|---|---|
| 1/2 | 4-3/4 | 0.84 | 4 | 7/8 | 3-1/4 |
| 3/4 | 5-1/8 | 1.05 | 4 | 7/8 | 3-1/2 |
| 1 | 5-7/8 | 1.32 | 4 | 1 | 4 |
| 1-1/4 | 6-1/4 | 1.66 | 4 | 1 | 4-3/8 |
| 1-1/2 | 7 | 1.90 | 4 | 1-1/8 | 4-7/8 |
| 2 | 8-1/2 | 2.38 | 8 | 1 | 6-1/2 |
| 2-1/2 | 9-5/8 | 2.88 | 8 | 1-1/8 | 7-1/2 |
| 3 | 9-1/2 | 3.50 | 8 | 1-1/8 | 7-1/2 |
| 4 | 11-1/2 | 4.50 | 8 | 1-1/4 | 9-1/4 |
| 5 | 13-3/4 | 5.56 | 8 | 1-3/8 | 11 |
| 6 | 15 | 6.63 | 12 | 1-1/4 | 12-1/2 |
| 8 | 18-1/2 | 8.63 | 12 | 1-1/2 | 15-1/2 |
| 10 | 21-1/2 | 10.75 | 16 | 1-1/2 | 18-1/2 |
| 12 | 24 | 12.75 | 20 | 1-1/2 | 21 |
| 14 | 25-1/4 | 14.00 | 20 | 1-5/8 | 22 |
| 16 | 27-3/4 | 16.00 | 20 | 1-3/4 | 24-1/4 |
| 18 | 31 | 18.00 | 20 | 2 | 27 |
| 20 | 33-3/4 | 20.00 | 20 | 2-1/8 | 29-1/2 |
| 24 | 41 | 24.00 | 20 | 2-5/8 | 35-1/2 |
| ANSI B16.5 covers only sizes through 24" | |||||
| 26 | 42 3/4 | 20 | 2 7/8 | 37 1/2 | |
| 28 | 46 | 20 | 3 1/8 | 40 1/4 | |
| 30 | 48 1/2 | 20 | 3 1/8 | 42 3/4 | |
| 32 | 51 3/4 | 20 | 3 3/8 | 45 1/2 | |
| 34 | 55 | 20 | 3 5/8 | 48 1/4 | |
| 36 | 57 1/2 | 20 | 3 5/8 | 50 3/4 | |
1) Recommended bolts are 1/8 smaller than the nominal bolt hole diameters shown.
- 1 inch = 25.4 mm
