Flange Bolt Chart
Lookup flange bolt lengths, wrench sizes, and torque sequences in seconds.
Flange Bolt Chart - Bolt Lengths, Wrench Sizes & Torque Patterns
150 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 0.875 | 4 | 0.5 | 2.25 | |
| 3/4 | 0.875 | 4 | 0.5 | 2.5 | |
| 1 | 0.875 | 4 | 0.5 | 2.5 | 3 |
| 1-1/4 | 0.875 | 4 | 0.5 | 2.75 | 3.25 |
| 1-1/2 | 0.875 | 4 | 0.5 | 2.75 | 3.25 |
| 2 | 1.063 | 4 | 0.625 | 3.25 | 3.75 |
| 2-1/2 | 1.063 | 4 | 0.625 | 3.5 | 4 |
| 3 | 1.063 | 4 | 0.625 | 3.5 | 4 |
| 3-1/2 | 1.063 | 8 | 0.625 | 3.5 | 4 |
| 4 | 1.063 | 8 | 0.625 | 3.5 | 4 |
| 5 | 1.25 | 8 | 0.75 | 3.75 | 4.25 |
| 6 | 1.25 | 8 | 0.75 | 4 | 4.5 |
| 8 | 1.25 | 8 | 0.75 | 4.25 | 4.75 |
| 10 | 1.438 | 12 | 0.875 | 4.5 | 5 |
| 12 | 1.438 | 12 | 0.875 | 4.75 | 5.25 |
| 14 | 1.625 | 12 | 1 | 5.25 | 5.75 |
| 16 | 1.625 | 16 | 1 | 5.25 | 5.75 |
| 18 | 1.813 | 16 | 1.125 | 5.75 | 6.25 |
| 20 | 1.813 | 20 | 1.125 | 6.25 | 6.75 |
| 22 | 2 | 20 | 1.25 | 6.75 | 7.25 |
| 24 | 2 | 20 | 1.25 | 6.75 | 7.25 |
Source: "ASME B16.5-2020 Table 7C Templates for Drilling Class 150 Pipe Flanges and Flanged Fittings"
300 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 0.875 | 4 | 0.5 | 2.5 | 3 |
| 3/4 | 1.063 | 4 | 0.625 | 3 | 3.5 |
| 1 | 1.063 | 4 | 0.625 | 3 | 3.5 |
| 1-1/4 | 1.063 | 4 | 0.625 | 3.25 | 3.75 |
| 1-1/2 | 1.25 | 4 | 0.75 | 3.5 | 4 |
| 2 | 1.063 | 8 | 0.625 | 3.5 | 4 |
| 2-1/2 | 1.25 | 8 | 0.75 | 4 | 4.5 |
| 3 | 1.25 | 8 | 0.75 | 4.25 | 4.75 |
| 3-1/2 | 1.25 | 8 | 0.75 | 4.25 | 5 |
| 4 | 1.25 | 8 | 0.75 | 4.5 | 5 |
| 5 | 1.25 | 8 | 0.75 | 4.75 | 5.25 |
| 6 | 1.25 | 12 | 0.75 | 4.75 | 5.5 |
| 8 | 1.438 | 12 | 0.875 | 5.5 | 6 |
| 10 | 1.625 | 16 | 1 | 6.25 | 6.75 |
| 12 | 1.813 | 16 | 1.125 | 6.75 | 7.25 |
| 14 | 1.813 | 20 | 1.125 | 7 | 7.5 |
| 16 | 2 | 20 | 1.25 | 7.5 | 8 |
| 18 | 2 | 24 | 1.25 | 7.75 | 8.25 |
| 20 | 2 | 24 | 1.25 | 8 | 8.75 |
| 22 | 2.375 | 24 | 1.5 | 9 | 10 |
| 24 | 2.375 | 24 | 1.5 | 9 | 10 |
Source: "ASME B16.5-2020 Table 10C Templates for Drilling Class 300 Pipe Flanges and Flanged Fittings"
400 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 0.875 | 4 | 0.5 | 3 | 3 |
| 3/4 | 1.063 | 4 | 0.625 | 3.5 | 3.5 |
| 1 | 1.063 | 4 | 0.625 | 3.5 | 3.5 |
| 1-1/4 | 1.063 | 4 | 0.625 | 3.75 | 3.75 |
| 1-1/2 | 1.25 | 4 | 0.75 | 4.25 | 4.25 |
| 2 | 1.063 | 8 | 0.625 | 4.25 | 4.25 |
| 2-1/2 | 1.25 | 8 | 0.75 | 4.75 | 4.75 |
| 3 | 1.25 | 8 | 0.75 | 5 | 5 |
| 3-1/2 | 1.438 | 8 | 0.875 | 5.5 | 5.5 |
| 4 | 1.438 | 8 | 0.875 | 5.5 | 5.5 |
| 5 | 1.438 | 8 | 0.875 | 5.75 | 5.75 |
| 6 | 1.438 | 12 | 0.875 | 6 | 6 |
| 8 | 1.625 | 12 | 1 | 6.75 | 6.75 |
| 10 | 1.813 | 16 | 1.125 | 7.5 | 7.5 |
| 12 | 2 | 16 | 1.25 | 8 | 8 |
| 14 | 2 | 20 | 1.25 | 8.25 | 8.25 |
| 16 | 2.188 | 20 | 1.375 | 8.75 | 8.75 |
| 18 | 2.188 | 24 | 1.375 | 9 | 9 |
| 20 | 2.375 | 24 | 1.5 | 9.5 | 9.75 |
| 22 | 2.563 | 24 | 1.625 | 10 | 10.25 |
| 24 | 2.75 | 24 | 1.75 | 10.5 | 11 |
Source: "ASME B16.5-2020 Table 13C Templates for Drilling Class 400 Pipe Flanges"
600 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 0.875 | 4 | 0.5 | 3 | 3 |
| 3/4 | 1.063 | 4 | 0.625 | 3.5 | 3.5 |
| 1 | 1.063 | 4 | 0.625 | 3.5 | 3.5 |
| 1-1/4 | 1.063 | 4 | 0.625 | 3.75 | 3.75 |
| 1-1/2 | 1.25 | 4 | 0.75 | 4.25 | 4.25 |
| 2 | 1.063 | 8 | 0.625 | 4.25 | 4.25 |
| 2-1/2 | 1.25 | 8 | 0.75 | 4.75 | 4.75 |
| 3 | 1.25 | 8 | 0.75 | 5 | 5 |
| 3-1/2 | 1.438 | 8 | 0.875 | 5.5 | 5.5 |
| 4 | 1.438 | 8 | 0.875 | 5.75 | 5.75 |
| 5 | 1.625 | 8 | 1 | 6.5 | 6.5 |
| 6 | 1.625 | 12 | 1 | 6.75 | 6.75 |
| 8 | 1.813 | 12 | 1.125 | 7.5 | 7.75 |
| 10 | 2 | 16 | 1.25 | 8.5 | 8.5 |
| 12 | 2 | 20 | 1.25 | 8.75 | 8.75 |
| 14 | 2.188 | 20 | 1.375 | 9.25 | 9.25 |
| 16 | 2.375 | 20 | 1.5 | 10 | 10 |
| 18 | 2.563 | 20 | 1.625 | 10.75 | 10.75 |
| 20 | 2.563 | 24 | 1.625 | 11.25 | 11.5 |
| 22 | 2.75 | 24 | 1.75 | 12 | 12.25 |
| 24 | 2.938 | 24 | 1.875 | 13 | 13.25 |
Source: "ASME B16.5-2020 Table 15C Templates for Drilling Class 600 Pipe Flanges and Flanged Fittings"
900 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 1.25 | 4 | 0.75 | 4.25 | 4.25 |
| 3/4 | 1.25 | 4 | 0.75 | 4.5 | 4.5 |
| 1 | 1.438 | 4 | 0.875 | 5 | 5 |
| 1-1/4 | 1.438 | 4 | 0.875 | 5 | 5 |
| 1-1/2 | 1.625 | 4 | 1 | 5.5 | 5.5 |
| 2 | 1.438 | 8 | 0.875 | 5.75 | 5.75 |
| 2-1/2 | 1.625 | 8 | 1 | 6.25 | 6.25 |
| 3 | 1.438 | 8 | 0.875 | 5.75 | 5.75 |
| 4 | 1.813 | 8 | 1.125 | 6.75 | 6.75 |
| 5 | 2 | 8 | 1.25 | 7.5 | 7.5 |
| 6 | 1.813 | 12 | 1.125 | 7.5 | 7.75 |
| 8 | 2.188 | 12 | 1.375 | 8.75 | 8.75 |
| 10 | 2.188 | 16 | 1.375 | 9.25 | 9.25 |
| 12 | 2.188 | 20 | 1.375 | 10 | 10 |
| 14 | 2.375 | 20 | 1.5 | 10.75 | 11 |
| 16 | 2.563 | 20 | 1.625 | 11.25 | 11.5 |
| 18 | 2.938 | 20 | 1.875 | 12.75 | 13.25 |
| 20 | 3.125 | 20 | 2 | 13.75 | 14.25 |
| 24 | 3.875 | 20 | 2.5 | 17.25 | 18 |
Source: "ASME B16.5-2020 Table 17C Templates for Drilling Class 900 Pipe Flanges and Flanged Fittings"
1500 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 1.25 | 4 | 0.75 | 4.25 | 4.25 |
| 3/4 | 1.25 | 4 | 0.75 | 4.5 | 4.5 |
| 1 | 1.438 | 4 | 0.875 | 5 | 5 |
| 1-1/4 | 1.438 | 4 | 0.875 | 5 | 5 |
| 1-1/2 | 1.625 | 4 | 1 | 5.5 | 5.5 |
| 2 | 1.438 | 8 | 0.875 | 5.75 | 5.75 |
| 2-1/2 | 1.625 | 8 | 1 | 6.25 | 6.25 |
| 3 | 1.813 | 8 | 1.125 | 7 | 7 |
| 4 | 2 | 8 | 1.25 | 7.75 | 7.75 |
| 5 | 2.375 | 8 | 1.5 | 9.75 | 9.75 |
| 6 | 2.188 | 12 | 1.375 | 10.25 | 10.5 |
| 8 | 2.563 | 12 | 1.625 | 11.5 | 11.75 |
| 10 | 2.938 | 12 | 1.875 | 13.25 | 13.5 |
| 12 | 3.125 | 16 | 2 | 14.75 | 15.25 |
| 14 | 3.5 | 16 | 2.25 | 16 | 16.75 |
| 16 | 3.875 | 16 | 2.5 | 17.5 | 18.5 |
| 18 | 4.25 | 16 | 2.75 | 19.5 | 20.75 |
| 20 | 4.625 | 16 | 3 | 21.25 | 22.25 |
| 24 | 5.375 | 16 | 3.5 | 24.25 | 25.5 |
Source: "ASME B16.5-2020 Table 19C Templates for Drilling Class 1500 Pipe Flanges"
2500 Class Flanges
| Nominal Pipe Size | Wrench Size (inches) | Number of Studs | Diameter of Studs (inches) | Length of Stud - RF (inches) | Length of Stud - RTJ (inches) |
|---|---|---|---|---|---|
| 1/2 | 1.25 | 4 | 0.75 | 4.75 | 4.75 |
| 3/4 | 1.25 | 4 | 0.75 | 5 | 5 |
| 1 | 1.438 | 4 | 0.875 | 5.5 | 5.5 |
| 1-1/4 | 1.625 | 4 | 1 | 6 | 6 |
| 1-1/2 | 1.813 | 4 | 1.125 | 6.75 | 6.75 |
| 2 | 1.625 | 8 | 1 | 7 | 7 |
| 2-1/2 | 1.813 | 8 | 1.125 | 7.75 | 8 |
| 3 | 2 | 8 | 1.25 | 8.75 | 9 |
| 4 | 2.375 | 8 | 1.5 | 10 | 10.25 |
| 5 | 2.75 | 8 | 1.75 | 11.75 | 12.25 |
| 6 | 3.125 | 8 | 2 | 13.5 | 14 |
| 8 | 3.125 | 12 | 2 | 15 | 15.5 |
| 10 | 3.875 | 12 | 2.5 | 19.25 | 20 |
| 12 | 4.25 | 12 | 2.75 | 21.25 | 22 |
Source: "ASME B16.5-2020 Table 21C Templates for Drilling Class 2500 Pipe Flanges"
Reference pages
About the App
Look up flange bolt sizes and torque patterns in three taps with Flange Bolt.
Just enter the flange size, type, and class, and the tool instantly shows the ASME values for:
1. Number of studs
2. Diameter of studs
3. Length of studs
4. Torque pattern
5. Suggested torque amount
All values other than suggested torque amount are sourced directly from flange bolt charts and flange torque charts in the ASME B16.5 "Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard" (2017).
Looking up flange bolt sizes and torque patterns with Flange Bolt is far faster and less error prone than searching through PDF charts and tables. The sole purpose of the tool is to make it as simple as possible for a pipefitters, steamfitters, and others working in piping to look up flange bolt size and torque pattern information.
Is there a feature you'd like from Flange Bolt that you don't see? Request it through the app and we'll do our best to add it to the development schedule.
Features of the app:
1. Full offline capability: No internet connection necessary to use. All data is stored locally on your phone. (The app requires minimum storage space overall)
2. Instant flange bolt sizes and torque patterns: Just enter the flange size, class, and type and the app instantly populates the correct values from the flange bolt size chart and the flange torque sequence chart, along with wrench size.
3. Flange torque sequence image: Each lookup shows the correct flange torque sequence image in picture form, with the studs numbered.
4. Suggested torque values
The information in this app covers:
(1) flanges with rating class designations 150, 300, 400, 600, 900, and 1500 in sizes NPS 1/2 through NPS 24 and flanges with rating class designation 2500 in sizes NPS 1/2 through NPS 12, with requirements given in U.S. Customary units with diameter of bolts and flange bolt holes expressed in inch units;
(2) flanged fittings with rating class designation 150 and 300 in sizes NPS 1/2 through NPS 24, with requirements given in U.S. Customary units with diameter of bolts and flange bolt holes expressed in inch units;
(3) flanged fittings with rating class designation 400, 600, 900, and 1500 in sizes NPS 1/2 through NPS 24 and flanged fittings with rating class designation 2500 in sizes NPS 1/2 through NPS 12 in U.S. Customary units.
That includes:
- 4 bolt flange pattern
- 8 bolt flange pattern
- 12 bolt flange pattern
- 16 bolt flange pattern
- 20 bolt flange pattern
- 14 bolt flange pattern