ASME B16.5 · Standard reference
ASME B16.5-2025 pressure ratings by material group
Tables 2-1.1 (SI units, bar) and 2-1.1C (U.S. Customary units, psig) of ASME B16.5-2025 give the maximum allowable working gage pressure for Group 1.1 flanges in Classes 150, 300, 400, 600, 900, 1500 and 2500. Group 1.1 is the carbon, carbon-manganese and low-nickel steel family. The SI table runs from 38 °C to 538 °C and the U.S. Customary table from 100 °F to 1,000 °F. The 2025 edition is a technical revision, not a reprint: its change record lists the rating tables as revised, so a rating taken from a 2017 or 2020 table should be re-read before it is reused.
A table is read by material, class and design temperature. The first row is a floor rather than an extra data point — at any temperature at or below 38 °C (100 °F) the 38 °C / 100 °F rating applies (para. 2.4). Linear interpolation is allowed between the listed temperatures. Interpolation between pressure classes is not, because each class is a separate rating curve, and values must not be extrapolated above the highest tabulated temperature. The SI and U.S. Customary tables are separate prints of the same ratings: para. 1.6 makes each system of units independent and states that the values are not exact equivalents, so convert only for information.
The page reproduces the complete Group 1.1 grids in both unit systems, preceded by the five material rows they apply to, and then the SI (bar) ratings for twelve further groups that cover most alloy and stainless steel flanges: Groups 1.5, 1.9, 1.10, 1.14, 1.15 and 1.17 (carbon-molybdenum, chromium-molybdenum, 9Cr and 9Cr-Mo-V steels) and Groups 2.1, 2.2, 2.3, 2.4, 2.5 and 2.6 (the 304, 316/317, 316L/304L, 321, 347/348 and 309H austenitic stainless families). The notes under each table carry the real service limits — graphite conversion, killed or normalized-and-tempered material, minimum carbon content, heat-treatment conditions and the pointer to para. 2.5.3 for minimum temperatures.
Only SI ratings are transcribed for the groups other than 1.1, and the U.S. Customary companion tables 2-1.5C to 2-2.6C are not repeated here. The remaining groups (1.2–1.4, 1.7, 1.11, 1.13, 1.18, 2.7–2.13 and 3.1–3.19) are also still only in the standard. A group number fixes the rating curve: a Group 2.3 forging is not rated from the Group 2.2 table even though both are 316-type steels.
- Standard
- ASME B16.5-2025
- Tables
- 2-1.1 and 2-1.1C; 12 further SI tables
- Material groups
- 1.1 plus 12 groups (see index)
- Classes
- 150, 300, 400, 600, 900, 1500, 2500
- Ambient rating
- 19.6 bar (Class 150, Group 1.1)
- Highest temperature
- 816 °C (Groups 2.1–2.6)
Materials the two tables apply to
Both tables name the same five material rows and the same accepted specifications. A flange made to one of these forgings, castings or plates is rated from Table 2-1.1 / 2-1.1C, provided the design temperature is inside the limit in the note marked against that row.
B16.5 · ASME B16.5-2025
| Nominal designation | Forgings | Castings | Plates |
|---|---|---|---|
| C-Si | A105 [Notes (1), (2)] | A216 Gr. WCB [Note (1)] | A515 Gr. 70 [Note (1)] |
| C-Mn-Si | A350 Gr. LF2 [Note (1)] | — | A516 Gr. 70 [Notes (1), (3)] |
| C-Mn-Si | — | — | A537 Cl. 1 [Note (4)] |
| C-Mn-Si-V | A350 Gr. LF6 Cl. 1 [Note (3)] | — | — |
| 3½Ni | A350 Gr. LF3 [Note (5)] | — | — |
Product forms are shown where the standard lists a specification; the standard prints an ellipsis in cells for which it lists no specification of that form, shown here as "—". The bracketed note numbers are explained in the footnotes under each rating table; note (6), minimum-temperature guidance, applies to both unit systems.
Material group index — which rating table applies
A group number is a set of material specifications, not a strength grade. First confirm the grade against Table 1.1-1, then read the rating from the table listed here. A 316L forging owns Group 2.3, not 2.2, and the two groups have different rating curves.
Only SI (bar) rating tables are reproduced for these groups. The U.S. Customary companion tables 2-1.5C to 2-2.6C are printed alongside them in the standard and are not repeated on this page.
B16.5 · ASME B16.5-2025
| Group | Typical materials | SI rating table |
|---|---|---|
| 1.5 | C-½Mo: A182 Gr. F1 (forging); A204 Gr. A / B (plate) | 2-1.5 |
| 1.9 | 1¼Cr-½Mo / 1¼Cr-½Mo-Si: A217 Gr. WC6; A182 Gr. F11 Cl. 2; A387 Gr. 11 Cl. 2 | 2-1.9 |
| 1.10 | 2¼Cr-1Mo: A182 Gr. F22 Cl. 3; A217 Gr. WC9; A387 Gr. 22 Cl. 2 | 2-1.10 |
| 1.14 | 9Cr-1Mo: A182 Gr. F9; A217 Gr. C12 | 2-1.14 |
| 1.15 | 9Cr-1Mo-V: A182 Gr. F91 Type 1; A217 Gr. C12A; A387 Gr. 91 Cl. 2 | 2-1.15 |
| 1.17 | 1Cr-½Mo and 5Cr-½Mo: A182 Gr. F12 Cl. 2 and A182 Gr. F5 (forgings only) | 2-1.17 |
| 2.1 | 18Cr-8Ni: A182 Gr. F304 / F304H; A351 Gr. CF3 / CF8; A240 Gr. 304 / 304H | 2-2.1 |
| 2.2 | 16Cr-12Ni-2Mo and relatives: A182 Gr. F316 / F316H / F317; A351 Gr. CF3M / CF8M / CG8M; A240 Gr. 316 / 316H / 317 | 2-2.2 |
| 2.3 | Low-carbon 300 series: A182 Gr. F304L / F316L / F317L; A240 Gr. 304L / 316L | 2-2.3 |
| 2.4 | 18Cr-10Ni-Ti: A182 Gr. F321 / F321H; A240 Gr. 321 / 321H | 2-2.4 |
| 2.5 | 18Cr-10Ni-Cb: A182 Gr. F347 / F347H / F348 / F348H; A240 Gr. 347 / 347H / 348 / 348H | 2-2.5 |
| 2.6 | 23Cr-12Ni: A240 Gr. 309H (plate only) | 2-2.6 |
Materials are shortened from Table 1.1-1; a group can contain more specifications than shown, and the standard lists forgings, castings and plates separately. Group 1.1 is described in the section above; the remaining groups have their own SI table below.
Table 2-1.1 — working pressure in bar (SI units)
Metric table. Pressures are bar, temperatures are degrees Celsius. The 538 °C row is the last tabulated condition and the "min. to 38" row covers every temperature at or below 38 °C.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (6)] | 19.6 | 51.0 | 68.0 | 102.0 | 153.1 | 255.1 | 425.1 |
| 50 | 19.1 | 49.8 | 66.4 | 99.6 | 149.3 | 248.9 | 414.9 |
| 100 | 17.7 | 46.7 | 62.3 | 93.4 | 140.1 | 233.5 | 389.1 |
| 150 | 15.8 | 45.1 | 60.1 | 90.1 | 135.2 | 225.3 | 375.4 |
| 200 | 13.8 | 43.8 | 58.4 | 87.6 | 131.5 | 219.1 | 365.1 |
| 250 | 12.1 | 42.0 | 56.0 | 83.9 | 125.9 | 209.8 | 349.7 |
| 300 | 10.2 | 39.9 | 53.2 | 79.8 | 119.7 | 199.5 | 332.6 |
| 325 | 9.3 | 38.7 | 51.6 | 77.3 | 116.0 | 193.4 | 322.3 |
| 350 | 8.4 | 37.6 | 50.2 | 75.3 | 112.9 | 188.2 | 313.7 |
| 375 | 7.4 | 36.4 | 48.5 | 72.8 | 109.2 | 182.1 | 303.4 |
| 400 | 6.5 | 34.6 | 46.2 | 69.3 | 103.9 | 173.1 | 288.6 |
| 425 | 5.5 | 28.7 | 38.3 | 57.5 | 86.2 | 143.7 | 239.4 |
| 450 | 4.6 | 23.0 | 30.6 | 45.9 | 68.9 | 114.9 | 191.4 |
| 475 | 3.7 | 17.5 | 23.3 | 35.0 | 52.5 | 87.4 | 145.7 |
| 500 | 2.8 | 11.5 | 15.4 | 23.0 | 34.6 | 57.6 | 96.0 |
| 538 | 1.4 | 5.8 | 7.7 | 11.6 | 17.4 | 29.0 | 48.4 |
- 1 Long service above 427 °C is allowed but not advised; continued exposure above 427 °C can turn the carbide phase of the steel into graphite.
- 2 Above 455 °C only killed steel may be used.
- 3 Not to be used above 260 °C.
- 4 Not to be used above 371 °C.
- 5 Not to be used above 343 °C.
- 6 See para. 2.5.3 on how to establish minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not.
Table 2-1.1C — working pressure in psig (U.S. Customary units)
U.S. Customary table. Pressures are psig, temperatures are degrees Fahrenheit. The materials, classes and note limits are the same as in the SI table; only the unit system and the temperature steps are printed differently.
B16.5 · ASME B16.5-2025
| Temperature °F | Class 150 psig | Class 300 psig | Class 400 psig | Class 600 psig | Class 900 psig | Class 1500 psig | Class 2500 psig |
|---|---|---|---|---|---|---|---|
| Min. to 100 [Note (6)] | 285 | 740 | 985 | 1,480 | 2,220 | 3,705 | 6,170 |
| 200 | 260 | 680 | 905 | 1,360 | 2,035 | 3,395 | 5,655 |
| 300 | 230 | 655 | 870 | 1,310 | 1,965 | 3,270 | 5,450 |
| 400 | 200 | 635 | 845 | 1,265 | 1,900 | 3,170 | 5,280 |
| 500 | 170 | 605 | 805 | 1,205 | 1,810 | 3,015 | 5,025 |
| 600 | 140 | 570 | 755 | 1,135 | 1,705 | 2,840 | 4,730 |
| 650 | 125 | 550 | 730 | 1,100 | 1,650 | 2,745 | 4,575 |
| 700 | 110 | 530 | 710 | 1,060 | 1,590 | 2,655 | 4,425 |
| 750 | 95 | 505 | 675 | 1,015 | 1,520 | 2,535 | 4,230 |
| 800 | 80 | 410 | 550 | 825 | 1,235 | 2,055 | 3,430 |
| 850 | 65 | 320 | 425 | 640 | 955 | 1,595 | 2,655 |
| 900 | 50 | 230 | 305 | 460 | 690 | 1,150 | 1,915 |
| 950 | 35 | 135 | 185 | 275 | 410 | 685 | 1,145 |
| 1,000 | 20 | 85 | 115 | 170 | 255 | 430 | 715 |
- 1 Long service above 800 °F is allowed but not advised; continued exposure above 800 °F can turn the carbide phase of the steel into graphite.
- 2 Above 850 °F only killed steel may be used.
- 3 Not to be used above 500 °F.
- 4 Not to be used above 700 °F.
- 5 Not to be used above 650 °F.
- 6 See para. 2.5.3 on how to establish minimum temperatures.
Maximum allowable working pressure in psig at the listed metal temperature. The temperature steps are those printed in the U.S. Customary table and do not match the SI steps. Linear interpolation is allowed between listed temperatures only.
Applying a rating to a flange
- Find the flange material group in Table 1.1-1. A105, A216 WCB, A515 Gr. 70, A350 LF2, A516 Gr. 70, A537 Cl. 1, A350 LF6 Cl. 1 and A350 LF3 are all Group 1.1, so all of them use Tables 2-1.1 / 2-1.1C.
- Use the design metal temperature, not the fluid temperature. The rating temperature is that of the pressure-containing shell (para. 2.4).
- At or below 38 °C (100 °F) take the first row; do not read the floor as a limit on how cold the part may run — the minimum-temperature rules are separate (note 6, para. 2.5.3).
- Interpolate linearly between the two temperatures that bracket the design temperature, in the table for the unit system you are working in. Do not interpolate between classes.
- Check the row note before using a hot rating: note (3) limits A350 LF6 Cl. 1 and A516 Gr. 70, note (4) limits A537 Cl. 1, note (5) limits A350 LF3, and note (2) requires killed steel above 455 °C (850 °F).
- The flange rating is one input to the joint design. The governing piping code may impose lower limits for the same material, and a mixed joint is rated at the lower of the two flange ratings (para. 2.3.2).
Group 1.5 — pressure–temperature ratings (SI units)
Carbon-molybdenum steel: A182 Gr. F1 forgings and A204 Gr. A / B plate — no casting is listed for this group. The SI table ends at 538 °C for every class. Note (1) covers graphite conversion above 470 °C and note (2) points to para. 2.5.3 for minimum temperatures.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (2)] | 18.4 | 48.0 | 64.0 | 96.0 | 144.0 | 240.0 | 400.0 |
| 50 | 18.4 | 48.0 | 64.0 | 96.0 | 144.0 | 240.0 | 400.0 |
| 100 | 17.7 | 48.0 | 64.0 | 96.0 | 144.0 | 240.0 | 400.0 |
| 150 | 15.8 | 47.3 | 63.1 | 94.6 | 141.9 | 236.6 | 394.3 |
| 200 | 13.8 | 45.9 | 61.2 | 91.7 | 137.6 | 229.4 | 382.3 |
| 250 | 12.1 | 44.4 | 59.2 | 88.9 | 133.3 | 222.2 | 370.3 |
| 300 | 10.2 | 43.2 | 57.6 | 86.4 | 129.6 | 216.0 | 360.0 |
| 325 | 9.3 | 42.6 | 56.8 | 85.2 | 127.7 | 212.9 | 354.9 |
| 350 | 8.4 | 41.9 | 55.8 | 83.6 | 125.5 | 209.1 | 348.7 |
| 375 | 7.4 | 40.5 | 53.9 | 80.7 | 121.2 | 201.9 | 336.1 |
| 400 | 6.5 | 38.0 | 50.7 | 76.2 | 114.2 | 190.4 | 317.1 |
| 425 | 5.5 | 36.8 | 48.9 | 73.2 | 109.8 | 183.0 | 304.7 |
| 450 | 4.6 | 35.4 | 47.3 | 71.1 | 106.5 | 177.5 | 295.9 |
| 475 | 3.7 | 34.4 | 45.9 | 68.8 | 103.2 | 171.6 | 286.3 |
| 500 | 2.8 | 23.3 | 31.1 | 46.7 | 70.0 | 116.7 | 194.6 |
| 538 | 1.4 | 11.2 | 14.9 | 22.4 | 33.5 | 55.9 | 93.2 |
- 1 After long exposure above 470 °C the carbide phase of carbon-molybdenum steel can convert to graphite; use above that temperature is permitted but not recommended.
- 2 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 1.9 — pressure–temperature ratings (SI units)
1¼Cr-½Mo and 1¼Cr-½Mo-Si: A217 Gr. WC6 castings, A182 Gr. F11 Cl. 2 forgings and A387 Gr. 11 Cl. 2 plate. Ratings are tabulated to 649 °C; note (2) caps the WC6 casting at 593 °C, note (1) requires normalized and tempered material and note (4) covers prolonged use above 595 °C.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (5)] | 19.8 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 51.5 | 68.7 | 103.0 | 154.6 | 257.6 | 429.4 |
| 150 | 15.8 | 49.8 | 66.4 | 99.6 | 149.3 | 248.9 | 414.9 |
| 200 | 13.8 | 47.9 | 63.9 | 95.9 | 143.8 | 239.7 | 399.4 |
| 250 | 12.1 | 46.3 | 61.7 | 92.6 | 138.9 | 231.4 | 385.7 |
| 300 | 10.2 | 45.0 | 60.0 | 90.0 | 135.0 | 225.1 | 375.0 |
| 325 | 9.3 | 43.3 | 57.6 | 86.3 | 129.6 | 215.9 | 358.9 |
| 350 | 8.4 | 41.9 | 55.8 | 83.6 | 125.5 | 209.1 | 348.7 |
| 375 | 7.4 | 40.5 | 53.9 | 80.7 | 121.2 | 201.9 | 336.1 |
| 400 | 6.5 | 38.0 | 50.7 | 76.2 | 114.2 | 190.4 | 317.1 |
| 425 | 5.5 | 36.8 | 48.9 | 73.2 | 109.8 | 183.0 | 304.7 |
| 450 | 4.6 | 35.4 | 47.3 | 71.1 | 106.5 | 177.5 | 295.9 |
| 475 | 3.7 | 34.4 | 45.9 | 68.8 | 103.2 | 171.6 | 286.3 |
| 500 | 2.8 | 25.0 | 33.3 | 50.0 | 75.0 | 125.0 | 208.3 |
| 538 | 1.4 | 15.1 | 20.1 | 30.1 | 45.2 | 75.3 | 125.5 |
| 550 | — | 12.4 | 16.6 | 24.9 | 37.3 | 62.2 | 103.7 |
| 575 | — | 8.6 | 11.5 | 17.3 | 25.9 | 43.2 | 72.0 |
| 600 | — | 6.0 | 8.0 | 12.1 | 18.1 | 30.2 | 50.3 |
| 625 | — | 4.3 | 5.7 | 8.5 | 12.8 | 21.3 | 35.5 |
| 649 | — | 2.8 | 3.8 | 5.7 | 8.5 | 14.1 | 23.6 |
- 1 Use normalized and tempered material only.
- 2 Not to be used above 593 °C.
- 3 The deliberate addition of any element not listed in ASTM A217, Table 1 is prohibited, except that calcium and manganese may be added for deoxidation.
- 4 Long exposure above 595 °C is permitted but not recommended.
- 5 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 1.10 — pressure–temperature ratings (SI units)
2¼Cr-1Mo: A182 Gr. F22 Cl. 3 forgings, A217 Gr. WC9 castings and A387 Gr. 22 Cl. 2 plate. The table runs to 649 °C; note (1) covers prolonged use above 595 °C, note (2) requires normalized and tempered material for the casting and note (3) restricts deliberate alloy additions.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (4)] | 19.8 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 51.5 | 68.7 | 103.0 | 154.6 | 257.6 | 429.4 |
| 150 | 15.8 | 50.3 | 67.0 | 100.3 | 150.6 | 250.8 | 418.2 |
| 200 | 13.8 | 48.6 | 64.8 | 97.2 | 145.8 | 243.4 | 405.4 |
| 250 | 12.1 | 46.3 | 61.8 | 92.7 | 139.0 | 231.8 | 386.2 |
| 300 | 10.2 | 45.0 | 60.0 | 90.0 | 135.0 | 225.1 | 375.0 |
| 325 | 9.3 | 43.3 | 57.6 | 86.3 | 129.6 | 215.9 | 359.8 |
| 350 | 8.4 | 41.9 | 55.8 | 83.6 | 125.5 | 209.1 | 348.7 |
| 375 | 7.4 | 40.5 | 53.9 | 80.7 | 121.2 | 201.9 | 336.1 |
| 400 | 6.5 | 38.0 | 50.7 | 76.2 | 114.2 | 190.4 | 317.1 |
| 425 | 5.5 | 36.8 | 48.9 | 73.2 | 109.8 | 183.0 | 304.7 |
| 450 | 4.6 | 35.4 | 47.3 | 71.1 | 106.5 | 177.5 | 295.9 |
| 475 | 3.7 | 34.4 | 45.9 | 68.8 | 103.2 | 171.6 | 286.3 |
| 500 | 2.8 | 30.7 | 40.9 | 61.3 | 92.0 | 153.3 | 255.4 |
| 538 | 1.4 | 18.6 | 24.7 | 37.1 | 55.7 | 92.8 | 154.6 |
| 550 | — | 15.4 | 20.5 | 30.8 | 46.2 | 77.0 | 128.3 |
| 575 | — | 10.3 | 13.8 | 20.6 | 31.0 | 51.6 | 86.0 |
| 600 | — | 6.8 | 9.0 | 13.5 | 20.3 | 33.8 | 56.3 |
| 625 | — | 4.4 | 5.9 | 8.8 | 13.3 | 22.1 | 36.9 |
| 649 | — | 2.8 | 3.8 | 5.7 | 8.5 | 14.1 | 23.6 |
- 1 Long exposure above 595 °C is permitted but not recommended.
- 2 Use normalized and tempered material only.
- 3 The deliberate addition of any element not listed in ASTM A217, Table 1 is prohibited, except that calcium and manganese may be added for deoxidation.
- 4 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 1.14 — pressure–temperature ratings (SI units)
9Cr-1Mo: A182 Gr. F9 forgings and A217 Gr. C12 castings — no plate specification is listed. Ratings run to 649 °C, with note (1) requiring normalized and tempered material and note (2) restricting deliberate alloy additions.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (3)] | 20.0 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 51.5 | 68.7 | 103.0 | 154.6 | 257.6 | 429.4 |
| 150 | 15.8 | 50.3 | 67.0 | 100.3 | 150.6 | 250.8 | 418.2 |
| 200 | 13.8 | 48.6 | 64.8 | 97.2 | 145.8 | 243.4 | 405.4 |
| 250 | 12.1 | 46.3 | 61.8 | 92.7 | 139.0 | 231.8 | 386.2 |
| 300 | 10.2 | 45.0 | 60.0 | 90.0 | 135.0 | 225.1 | 375.0 |
| 325 | 9.3 | 43.3 | 57.6 | 86.3 | 129.6 | 215.9 | 359.8 |
| 350 | 8.4 | 41.9 | 55.8 | 83.6 | 125.5 | 209.1 | 348.7 |
| 375 | 7.4 | 40.5 | 53.9 | 80.7 | 121.2 | 201.9 | 336.1 |
| 400 | 6.5 | 38.0 | 50.7 | 76.2 | 114.2 | 190.4 | 317.1 |
| 425 | 5.5 | 36.8 | 48.9 | 73.2 | 109.8 | 183.0 | 304.7 |
| 450 | 4.6 | 35.4 | 47.3 | 71.1 | 106.5 | 177.5 | 295.9 |
| 475 | 3.7 | 34.4 | 45.9 | 68.8 | 103.2 | 171.6 | 286.3 |
| 500 | 2.8 | 30.2 | 40.3 | 60.5 | 90.7 | 151.2 | 252.0 |
| 538 | 1.4 | 17.7 | 23.6 | 35.3 | 53.0 | 88.4 | 147.3 |
| 550 | — | 14.7 | 19.7 | 29.5 | 44.2 | 73.7 | 122.9 |
| 575 | — | 10.3 | 13.7 | 20.6 | 30.9 | 51.4 | 85.7 |
| 600 | — | 7.1 | 9.4 | 14.1 | 21.2 | 35.3 | 58.9 |
| 625 | — | 4.9 | 6.6 | 9.9 | 14.8 | 24.7 | 41.1 |
| 649 | — | 3.6 | 4.7 | 7.1 | 10.7 | 17.8 | 29.6 |
- 1 Use normalized and tempered material only.
- 2 The deliberate addition of any element not listed in ASTM A217, Table 1 is prohibited, except that calcium and manganese may be added for deoxidation.
- 3 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 1.15 — pressure–temperature ratings (SI units)
9Cr-1Mo-V: A182 Gr. F91 Type 1 forgings, A217 Gr. C12A castings and A387 Gr. 91 Cl. 2 plate. Note (1) restricts deliberate alloy additions. This is the Grade 91 group — the creep-strength-enhanced ferritic steel used for high-temperature steam piping.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (2)] | 20.0 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 51.5 | 68.7 | 103.0 | 154.6 | 257.6 | 429.4 |
| 150 | 15.8 | 50.3 | 67.0 | 100.3 | 150.6 | 250.8 | 418.2 |
| 200 | 13.8 | 48.6 | 64.8 | 97.2 | 145.8 | 243.4 | 405.4 |
| 250 | 12.1 | 46.3 | 61.8 | 92.7 | 139.0 | 231.8 | 386.2 |
| 300 | 10.2 | 45.0 | 60.0 | 90.0 | 135.0 | 225.1 | 375.0 |
| 325 | 9.3 | 43.3 | 57.6 | 86.3 | 129.6 | 215.9 | 359.8 |
| 350 | 8.4 | 41.9 | 55.8 | 83.6 | 125.5 | 209.1 | 348.7 |
| 375 | 7.4 | 40.5 | 53.9 | 80.7 | 121.2 | 201.9 | 336.1 |
| 400 | 6.5 | 38.0 | 50.7 | 76.2 | 114.2 | 190.4 | 317.1 |
| 425 | 5.5 | 36.8 | 48.9 | 73.2 | 109.8 | 183.0 | 304.7 |
| 450 | 4.6 | 35.4 | 47.3 | 71.1 | 106.5 | 177.5 | 295.9 |
| 475 | 3.7 | 34.4 | 45.9 | 68.8 | 103.2 | 171.6 | 286.3 |
| 500 | 2.8 | 32.1 | 42.9 | 64.4 | 96.6 | 160.6 | 267.9 |
| 538 | 1.4 | 29.0 | 38.5 | 57.5 | 86.5 | 144.3 | 240.2 |
| 550 | — | 28.8 | 38.3 | 57.3 | 86.0 | 143.6 | 239.2 |
| 575 | — | 25.9 | 34.5 | 51.8 | 77.7 | 129.4 | 215.7 |
| 600 | — | 18.6 | 24.8 | 37.2 | 55.9 | 93.1 | 155.1 |
| 625 | — | 12.6 | 16.8 | 25.2 | 37.9 | 63.1 | 105.1 |
| 649 | — | 8.4 | 11.2 | 16.8 | 25.2 | 42.0 | 70.0 |
- 1 The deliberate addition of any element not listed in ASTM A217, Table 1 is prohibited, except that calcium and manganese may be added for deoxidation.
- 2 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 1.17 — pressure–temperature ratings (SI units)
Two chromium-molybdenum steels with no castings or plate listed: 1Cr-½Mo (A182 Gr. F12 Cl. 2) and 5Cr-½Mo (A182 Gr. F5). Ratings run to 649 °C; note (1) requires normalized and tempered material and note (2) covers prolonged use above 595 °C.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (3)] | 19.8 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.6 | 68.7 | 103.1 | 154.7 | 257.8 | 429.6 |
| 100 | 17.7 | 50.6 | 67.4 | 101.1 | 151.7 | 252.9 | 421.4 |
| 150 | 15.8 | 48.1 | 64.2 | 96.3 | 144.4 | 240.7 | 401.1 |
| 200 | 13.8 | 46.3 | 61.7 | 92.6 | 138.9 | 231.4 | 385.7 |
| 250 | 12.1 | 44.8 | 59.8 | 89.7 | 134.5 | 224.2 | 373.7 |
| 300 | 10.2 | 43.6 | 58.1 | 87.2 | 130.8 | 218.1 | 363.4 |
| 325 | 9.3 | 43.0 | 57.3 | 86.0 | 129.0 | 215.0 | 358.3 |
| 350 | 8.4 | 41.9 | 55.8 | 83.6 | 125.5 | 209.1 | 348.7 |
| 375 | 7.4 | 40.5 | 53.9 | 80.7 | 121.2 | 201.9 | 336.1 |
| 400 | 6.5 | 38.0 | 50.7 | 76.2 | 114.2 | 190.4 | 317.1 |
| 425 | 5.5 | 36.8 | 48.9 | 73.2 | 109.8 | 183.0 | 304.7 |
| 450 | 4.6 | 35.0 | 46.6 | 69.9 | 104.9 | 174.9 | 291.4 |
| 475 | 3.7 | 27.8 | 37.1 | 55.6 | 83.4 | 139.0 | 231.7 |
| 500 | 2.8 | 21.2 | 28.3 | 42.4 | 63.6 | 105.9 | 176.6 |
| 538 | 1.4 | 13.8 | 18.4 | 27.6 | 41.5 | 69.1 | 115.2 |
| 550 | — | 11.9 | 15.9 | 23.8 | 35.7 | 59.5 | 99.1 |
| 575 | — | 8.8 | 11.8 | 17.7 | 26.5 | 44.2 | 73.7 |
| 600 | — | 5.9 | 7.9 | 11.9 | 17.8 | 29.7 | 49.4 |
| 625 | — | 3.9 | 5.3 | 7.9 | 11.8 | 19.7 | 32.9 |
| 649 | — | 2.4 | 3.1 | 4.7 | 7.1 | 11.8 | 19.6 |
- 1 Use normalized and tempered material only.
- 2 Long exposure above 595 °C is permitted but not recommended.
- 3 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 2.1 — pressure–temperature ratings (SI units)
18Cr-8Ni austenitic stainless, standard carbon: A182 Gr. F304 / F304H forgings, A351 Gr. CF3 / CF8 castings and A240 Gr. 304 / 304H plate. The table runs from the 38 °C floor to 816 °C; Class 150 stops at 538 °C. Note (1) requires carbon of 0.04% or more above 538 °C and note (2) caps the CF3 casting at 427 °C.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (3)] | 19.1 | 49.7 | 66.3 | 99.4 | 149.1 | 248.6 | 414.3 |
| 50 | 18.5 | 48.3 | 64.5 | 96.7 | 145.0 | 241.7 | 402.9 |
| 100 | 15.6 | 40.8 | 54.4 | 81.6 | 122.4 | 204.0 | 340.0 |
| 150 | 14.2 | 37.0 | 49.4 | 74.1 | 111.1 | 185.1 | 308.6 |
| 200 | 13.1 | 34.3 | 45.7 | 68.6 | 102.9 | 171.4 | 285.7 |
| 250 | 12.1 | 32.2 | 42.9 | 64.3 | 96.5 | 160.8 | 268.0 |
| 300 | 10.2 | 31.0 | 41.3 | 61.9 | 92.9 | 154.8 | 258.0 |
| 325 | 9.3 | 30.2 | 40.3 | 60.5 | 90.7 | 151.2 | 252.0 |
| 350 | 8.4 | 29.5 | 39.4 | 59.0 | 88.6 | 147.6 | 246.0 |
| 375 | 7.4 | 29.0 | 38.7 | 58.1 | 87.1 | 145.2 | 242.0 |
| 400 | 6.5 | 28.3 | 37.8 | 56.6 | 85.0 | 141.6 | 236.0 |
| 425 | 5.5 | 28.1 | 37.4 | 56.2 | 84.2 | 140.4 | 234.0 |
| 450 | 4.6 | 27.4 | 36.5 | 54.7 | 82.1 | 136.8 | 228.0 |
| 475 | 3.7 | 26.9 | 35.8 | 53.8 | 80.6 | 134.4 | 224.0 |
| 500 | 2.8 | 26.4 | 35.2 | 52.8 | 79.2 | 132.0 | 220.0 |
| 538 | 1.4 | 24.4 | 32.5 | 48.8 | 73.2 | 122.1 | 203.4 |
| 550 | — | 24.0 | 32.0 | 48.0 | 72.0 | 120.0 | 200.0 |
| 575 | — | 21.0 | 28.0 | 42.0 | 62.9 | 104.9 | 174.9 |
| 600 | — | 16.8 | 22.4 | 33.6 | 50.4 | 84.0 | 140.0 |
| 625 | — | 13.7 | 18.3 | 27.5 | 41.2 | 68.7 | 114.6 |
| 650 | — | 11.2 | 15.0 | 22.5 | 33.7 | 56.2 | 93.7 |
| 675 | — | 9.3 | 12.4 | 18.7 | 28.0 | 46.6 | 77.7 |
| 700 | — | 8.0 | 10.7 | 16.0 | 24.1 | 40.1 | 66.9 |
| 725 | — | 6.7 | 9.0 | 13.4 | 20.2 | 33.6 | 56.0 |
| 750 | — | 5.7 | 7.6 | 11.5 | 17.2 | 28.6 | 47.7 |
| 775 | — | 4.8 | 6.4 | 9.5 | 14.3 | 23.8 | 39.7 |
| 800 | — | 3.8 | 5.1 | 7.6 | 11.4 | 19.0 | 31.7 |
| 816 | — | 3.3 | 4.4 | 6.6 | 9.9 | 16.4 | 27.4 |
- 1 Above 538 °C use only when the carbon content is 0.04% or higher.
- 2 Not to be used above 427 °C.
- 3 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 2.2 — pressure–temperature ratings (SI units)
The molybdenum-bearing 300 series: A182 Gr. F316 / F316H / F317 forgings, A351 Gr. CF3M / CF8M / CG8M castings and A240 Gr. 316 / 316H / 317 plate. Ratings run to 816 °C; note (1) requires carbon of 0.04% or more above 538 °C, note (2) caps CF3M at 454 °C and note (3) caps CG8M at 538 °C.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (4)] | 19.1 | 49.7 | 66.3 | 99.4 | 149.1 | 248.6 | 414.3 |
| 50 | 18.5 | 48.3 | 64.5 | 96.7 | 145.0 | 241.7 | 402.9 |
| 100 | 16.2 | 42.2 | 56.2 | 84.3 | 126.5 | 210.9 | 351.4 |
| 150 | 14.7 | 38.4 | 51.2 | 76.8 | 115.2 | 192.0 | 320.0 |
| 200 | 13.7 | 35.7 | 47.5 | 71.3 | 107.0 | 178.3 | 297.1 |
| 250 | 12.1 | 33.4 | 44.5 | 66.7 | 100.1 | 166.8 | 278.0 |
| 300 | 10.2 | 31.4 | 41.9 | 62.9 | 94.3 | 157.2 | 262.0 |
| 325 | 9.3 | 31.0 | 41.3 | 61.9 | 92.9 | 154.8 | 258.0 |
| 350 | 8.4 | 30.2 | 40.3 | 60.5 | 90.7 | 151.2 | 252.0 |
| 375 | 7.4 | 29.8 | 39.7 | 59.5 | 89.3 | 148.8 | 248.0 |
| 400 | 6.5 | 29.5 | 39.4 | 59.0 | 88.6 | 147.6 | 246.0 |
| 425 | 5.5 | 29.0 | 38.7 | 58.1 | 87.1 | 145.2 | 242.0 |
| 450 | 4.6 | 28.8 | 38.4 | 57.6 | 86.4 | 144.0 | 240.0 |
| 475 | 3.7 | 28.6 | 38.1 | 57.1 | 85.7 | 142.8 | 238.0 |
| 500 | 2.8 | 28.3 | 37.8 | 56.6 | 85.0 | 141.6 | 236.0 |
| 538 | 1.4 | 26.7 | 35.6 | 53.4 | 80.1 | 133.5 | 222.6 |
| 550 | — | 26.6 | 35.5 | 53.2 | 79.8 | 133.0 | 221.7 |
| 575 | — | 25.3 | 33.7 | 50.5 | 75.8 | 126.3 | 210.6 |
| 600 | — | 19.9 | 26.5 | 39.7 | 59.6 | 99.3 | 165.4 |
| 625 | — | 15.8 | 21.0 | 31.5 | 47.3 | 78.9 | 131.4 |
| 650 | — | 12.7 | 16.9 | 25.3 | 38.0 | 63.3 | 105.4 |
| 675 | — | 10.3 | 13.8 | 20.6 | 31.0 | 51.6 | 86.0 |
| 700 | — | 8.3 | 11.1 | 16.7 | 25.0 | 41.7 | 69.4 |
| 725 | — | 7.0 | 9.3 | 13.9 | 20.9 | 34.8 | 58.0 |
| 750 | — | 5.8 | 7.8 | 11.7 | 17.5 | 29.1 | 48.6 |
| 775 | — | 4.6 | 6.1 | 9.2 | 13.8 | 23.0 | 38.3 |
| 800 | — | 3.6 | 4.8 | 7.1 | 10.7 | 17.8 | 29.7 |
| 816 | — | 3.1 | 4.1 | 6.1 | 9.2 | 15.3 | 25.4 |
- 1 Above 538 °C use only when the carbon content is 0.04% or higher.
- 2 Not to be used above 454 °C.
- 3 Not to be used above 538 °C.
- 4 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 2.3 — pressure–temperature ratings (SI units)
Low-carbon austenitic stainless: A182 Gr. F304L / F316L / F317L forgings and A240 Gr. 304L / 316L plate — no castings are listed. This is the shortest table on the page: it stops at 454 °C, the limit set by note (1) for every specification in the group.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (2)] | 15.8 | 41.1 | 54.9 | 82.3 | 123.4 | 205.7 | 342.9 |
| 50 | 15.5 | 40.5 | 53.9 | 80.9 | 121.4 | 202.3 | 337.1 |
| 100 | 13.4 | 35.0 | 46.6 | 69.9 | 104.9 | 174.9 | 291.4 |
| 150 | 12.1 | 31.4 | 41.9 | 62.9 | 94.3 | 157.2 | 262.0 |
| 200 | 11.1 | 29.0 | 38.7 | 58.1 | 87.1 | 145.2 | 242.0 |
| 250 | 10.5 | 27.4 | 36.5 | 54.7 | 82.1 | 136.8 | 228.0 |
| 300 | 9.9 | 25.9 | 34.6 | 51.8 | 77.8 | 129.6 | 216.0 |
| 325 | 9.3 | 25.4 | 33.9 | 50.9 | 76.3 | 127.2 | 212.0 |
| 350 | 8.4 | 25.0 | 33.3 | 49.9 | 74.9 | 124.8 | 208.0 |
| 375 | 7.4 | 24.7 | 33.0 | 49.4 | 74.2 | 123.6 | 206.0 |
| 400 | 6.5 | 24.2 | 32.3 | 48.5 | 72.7 | 121.2 | 202.0 |
| 425 | 5.5 | 23.9 | 31.8 | 47.7 | 71.6 | 119.3 | 198.9 |
| 454 | 4.6 | 23.4 | 31.2 | 46.8 | 70.3 | 117.1 | 195.1 |
- 1 Not to be used above 454 °C.
- 2 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 2.4 — pressure–temperature ratings (SI units)
Titanium-stabilised austenitic stainless: A182 Gr. F321 / F321H forgings and A240 Gr. 321 / 321H plate. Ratings run to 816 °C; note (1) caps the standard-carbon grades at 538 °C and note (2) allows the H grades above 538 °C only after a minimum 1 093 °C heat treatment.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (3)] | 19.1 | 49.7 | 66.3 | 99.4 | 149.1 | 248.6 | 414.3 |
| 50 | 18.7 | 48.7 | 64.9 | 97.4 | 146.1 | 243.4 | 405.7 |
| 100 | 17.0 | 44.2 | 59.0 | 88.5 | 132.7 | 221.1 | 368.6 |
| 150 | 15.8 | 41.1 | 54.9 | 82.3 | 123.4 | 205.7 | 342.9 |
| 200 | 13.8 | 38.4 | 51.2 | 76.8 | 115.2 | 192.0 | 320.0 |
| 250 | 12.1 | 36.0 | 48.0 | 72.0 | 108.0 | 180.0 | 300.0 |
| 300 | 10.2 | 34.1 | 45.4 | 68.2 | 102.2 | 170.4 | 284.0 |
| 325 | 9.3 | 33.4 | 44.5 | 66.7 | 100.1 | 166.8 | 278.0 |
| 350 | 8.4 | 32.6 | 43.5 | 65.3 | 97.9 | 163.2 | 272.0 |
| 375 | 7.4 | 31.9 | 42.6 | 63.8 | 95.8 | 159.6 | 266.0 |
| 400 | 6.5 | 31.7 | 42.2 | 63.4 | 95.0 | 158.4 | 264.0 |
| 425 | 5.5 | 31.2 | 41.6 | 62.4 | 93.6 | 156.0 | 260.0 |
| 450 | 4.6 | 30.7 | 41.0 | 61.4 | 92.2 | 153.6 | 256.0 |
| 475 | 3.7 | 30.5 | 40.6 | 61.0 | 91.4 | 152.4 | 254.0 |
| 500 | 2.8 | 30.2 | 40.3 | 60.5 | 90.7 | 151.2 | 252.0 |
| 538 | 1.4 | 27.5 | 36.7 | 55.0 | 82.5 | 137.5 | 229.1 |
| 550 | — | 27.5 | 36.7 | 55.0 | 82.5 | 137.5 | 229.1 |
| 575 | — | 26.6 | 35.5 | 53.3 | 79.9 | 133.2 | 220.0 |
| 600 | — | 20.1 | 26.8 | 40.3 | 60.4 | 100.6 | 167.7 |
| 625 | — | 15.8 | 21.0 | 31.5 | 47.3 | 78.9 | 131.4 |
| 650 | — | 12.7 | 16.9 | 25.3 | 38.0 | 63.3 | 105.4 |
| 675 | — | 9.8 | 13.1 | 19.7 | 29.5 | 49.2 | 82.0 |
| 700 | — | 7.9 | 10.5 | 15.7 | 23.6 | 39.3 | 65.4 |
| 725 | — | 6.3 | 8.4 | 12.6 | 18.9 | 31.5 | 52.6 |
| 750 | — | 4.9 | 6.6 | 9.9 | 14.8 | 24.7 | 41.1 |
| 775 | — | 3.9 | 5.3 | 7.9 | 11.8 | 19.7 | 32.9 |
| 800 | — | 3.1 | 4.2 | 6.3 | 9.4 | 15.7 | 26.2 |
| 816 | — | 2.6 | 3.5 | 5.2 | 7.8 | 12.9 | 21.6 |
- 1 Not to be used above 538 °C.
- 2 For temperatures above 538 °C use only if the material is heat treated by heating to a minimum temperature of 1 093 °C.
- 3 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 2.5 — pressure–temperature ratings (SI units)
Niobium-stabilised austenitic stainless: A182 Gr. F347 / F347H / F348 / F348H forgings and A240 Gr. 347 / 347H / 348 / 348H plate. Ratings run to 816 °C; note (1) caps the standard-carbon grades at 538 °C, note (2) requires the 1 093 °C heat treatment above 538 °C for the H grades, and note (3) caps A240 Gr. 348H plate at 425 °C.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (4)] | 19.1 | 49.7 | 66.3 | 99.4 | 149.1 | 248.6 | 414.3 |
| 50 | 18.8 | 49.0 | 65.4 | 98.1 | 147.1 | 245.1 | 408.6 |
| 100 | 17.3 | 45.3 | 60.3 | 90.5 | 135.8 | 226.3 | 377.1 |
| 150 | 15.8 | 42.5 | 56.7 | 85.0 | 127.5 | 212.6 | 354.3 |
| 200 | 13.8 | 39.8 | 53.0 | 79.5 | 119.3 | 198.9 | 331.4 |
| 250 | 12.1 | 37.7 | 50.3 | 75.4 | 113.1 | 188.6 | 314.3 |
| 300 | 10.2 | 36.0 | 48.0 | 72.0 | 108.0 | 180.0 | 300.0 |
| 325 | 9.3 | 35.3 | 47.1 | 70.6 | 105.9 | 176.6 | 294.3 |
| 350 | 8.4 | 35.0 | 46.6 | 69.9 | 104.9 | 174.9 | 291.4 |
| 375 | 7.4 | 34.1 | 45.4 | 68.2 | 102.2 | 170.4 | 284.0 |
| 400 | 6.5 | 33.8 | 45.1 | 67.7 | 101.5 | 169.2 | 282.0 |
| 425 | 5.5 | 33.6 | 44.8 | 67.2 | 100.8 | 168.0 | 280.0 |
| 450 | 4.6 | 33.4 | 44.5 | 66.7 | 100.1 | 166.8 | 278.0 |
| 475 | 3.7 | 33.4 | 44.5 | 66.7 | 100.1 | 166.8 | 278.0 |
| 500 | 2.8 | 32.1 | 42.9 | 64.4 | 96.6 | 160.6 | 267.9 |
| 538 | 1.4 | 29.0 | 38.5 | 57.5 | 86.5 | 144.3 | 240.2 |
| 550 | — | 28.8 | 38.3 | 57.3 | 86.0 | 143.6 | 239.2 |
| 575 | — | 27.8 | 37.1 | 55.6 | 83.3 | 138.9 | 231.4 |
| 600 | — | 25.3 | 33.6 | 50.2 | 75.1 | 125.2 | 208.8 |
| 625 | — | 21.5 | 28.7 | 43.0 | 64.5 | 107.2 | 178.6 |
| 650 | — | 16.6 | 22.1 | 33.2 | 50.2 | 83.4 | 138.9 |
| 675 | — | 14.2 | 18.9 | 28.4 | 42.6 | 71.0 | 118.3 |
| 700 | — | 10.9 | 14.5 | 21.8 | 32.7 | 54.5 | 90.9 |
| 725 | — | 8.2 | 10.9 | 16.4 | 24.6 | 41.0 | 68.3 |
| 750 | — | 6.4 | 8.6 | 12.9 | 19.3 | 32.2 | 53.7 |
| 775 | — | 5.0 | 6.7 | 10.0 | 15.0 | 25.0 | 41.7 |
| 800 | — | 3.7 | 4.9 | 7.4 | 11.1 | 18.5 | 30.9 |
| 816 | — | 3.1 | 4.1 | 6.1 | 9.2 | 15.3 | 25.4 |
- 1 Not to be used above 538 °C.
- 2 For temperatures above 538 °C use only if the material is heat treated by heating to a minimum temperature of 1 093 °C.
- 3 Not to be used above 425 °C.
- 4 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
Group 2.6 — pressure–temperature ratings (SI units)
23Cr-12Ni high-chromium stainless, A240 Gr. 309H plate only — no forging or casting is listed for this group. Ratings run to 816 °C and Class 150 stops at 538 °C. The single table note points to para. 2.5.3 for minimum temperatures.
B16.5 · ASME B16.5-2025
| Temperature °C | Class 150 bar | Class 300 bar | Class 400 bar | Class 600 bar | Class 900 bar | Class 1500 bar | Class 2500 bar |
|---|---|---|---|---|---|---|---|
| Min. to 38 [Note (1)] | 19.1 | 49.7 | 66.3 | 99.4 | 149.1 | 248.6 | 414.3 |
| 50 | 18.5 | 48.3 | 64.5 | 96.7 | 145.0 | 241.7 | 402.9 |
| 100 | 16.4 | 42.9 | 57.1 | 85.7 | 128.6 | 214.3 | 357.1 |
| 150 | 15.4 | 40.1 | 53.5 | 80.2 | 120.3 | 200.6 | 334.3 |
| 200 | 13.8 | 37.7 | 50.3 | 75.4 | 113.1 | 188.6 | 314.3 |
| 250 | 12.1 | 36.0 | 48.0 | 72.0 | 108.0 | 180.0 | 300.0 |
| 300 | 10.2 | 35.0 | 46.6 | 69.9 | 104.9 | 174.9 | 291.4 |
| 325 | 9.3 | 34.3 | 45.7 | 68.6 | 102.9 | 171.4 | 285.7 |
| 350 | 8.4 | 33.8 | 45.1 | 67.7 | 101.5 | 169.2 | 282.0 |
| 375 | 7.4 | 33.4 | 44.5 | 66.7 | 100.1 | 166.8 | 278.0 |
| 400 | 6.5 | 33.1 | 44.2 | 66.2 | 99.4 | 165.6 | 276.0 |
| 425 | 5.5 | 32.6 | 43.5 | 65.3 | 97.9 | 163.2 | 272.0 |
| 450 | 4.6 | 32.2 | 42.9 | 64.3 | 96.5 | 160.8 | 268.0 |
| 475 | 3.7 | 31.7 | 42.2 | 63.4 | 95.0 | 158.4 | 264.0 |
| 500 | 2.8 | 31.2 | 41.6 | 62.4 | 93.6 | 156.0 | 260.0 |
| 538 | 1.4 | 28.1 | 37.5 | 56.2 | 84.3 | 140.6 | 234.3 |
| 550 | — | 27.1 | 36.1 | 54.1 | 81.2 | 135.3 | 225.4 |
| 575 | — | 22.4 | 29.6 | 44.7 | 67.1 | 111.8 | 186.3 |
| 600 | — | 16.7 | 22.2 | 33.3 | 50.0 | 83.3 | 138.9 |
| 625 | — | 12.4 | 16.6 | 24.9 | 37.3 | 62.2 | 103.7 |
| 650 | — | 9.4 | 12.5 | 18.7 | 28.1 | 46.8 | 78.0 |
| 675 | — | 7.2 | 9.6 | 14.5 | 21.7 | 36.2 | 60.3 |
| 700 | — | 5.5 | 7.3 | 10.9 | 16.4 | 27.3 | 45.4 |
| 725 | — | 4.3 | 5.7 | 8.6 | 12.9 | 21.4 | 35.7 |
| 750 | — | 3.4 | 4.5 | 6.8 | 10.2 | 17.0 | 28.3 |
| 775 | — | 2.7 | 3.6 | 5.3 | 8.0 | 13.3 | 22.2 |
| 800 | — | 2.1 | 2.8 | 4.2 | 6.3 | 10.5 | 17.5 |
| 816 | — | 1.8 | 2.3 | 3.5 | 5.3 | 8.8 | 14.7 |
- 1 See para. 2.5.3 for guidance on determining minimum temperatures.
Maximum allowable working pressure in bar at the listed metal temperature. Values fall or stay level as the temperature rises. Linear interpolation is allowed between the listed temperatures; interpolation between classes and any extrapolation are not. A class the standard does not rate at that temperature is printed there as an ellipsis and is shown here as "—".
U.S. Customary tables and the groups not reproduced here
ASME B16.5-2025 prints a U.S. Customary companion table for every rating table — 2-1.5C through 2-2.6C for the groups on this page — and each is printed next to its SI table. Those psig tables are not reproduced here because the values are independent prints of the same ratings, not conversions of the bar values: use the table for the unit system you are working in (para. 1.6).
The group 1.1 U.S. Customary table (2-1.1C) is reproduced above because Group 1.1 is the one group shown in both unit systems. Groups 2.7–2.13 and 3.1–3.19, and all U.S. Customary tables other than 2-1.1C, are still only in the standard. The purchased 2025 edition governs.
ASME B16.5 pressure–temperature ratings — questions
Are these the revised 2025 ratings or values carried over from 2020?
These are transcribed cell by cell from Tables 2-1.1 and 2-1.1C of the 2025 edition. The 2025 Summary of Changes records the pressure–temperature rating tables as revised after the ceiling values in Nonmandatory Appendix A, Tables A-1 and A-2 were changed. A value copied from a 2017 or 2020 table is therefore not automatically valid for the 2025 edition and should be re-read.
What is the allowable pressure of a Class 150 Group 1.1 flange at 20 °C?
19.6 bar (285 psig). The first row of each table — "min. to 38 °C" / "min. to 100 °F" — covers every temperature at or below 38 °C (100 °F), so a lower ambient temperature does not increase the rating (para. 2.4).
Why do the bar and psig values not convert exactly into each other?
ASME B16.5 states the two unit systems as independent standards and says the values are not exact equivalents (para. 1.6). Convert only when a number must be understood in the other system; do not mix SI and U.S. Customary values in the same calculation or on the same datasheet, which the standard treats as nonconformance.
Can the table be extrapolated above 538 °C (1,000 °F)?
No. 538 °C (1,000 °F) is the highest tabulated temperature for Group 1.1 and the standard permits interpolation only between the listed temperatures. Group 1.1 carbon steels are also limited below that temperature by the row notes, for example A350 LF3 at 343 °C and A350 LF6 Cl. 1 at 260 °C.
Which material group is A182 F316L?
Group 2.3. Table 1.1-1 lists A182 Gr. F316L, A240 Gr. 316L and A182 Gr. F317L under Group 2.3, so the rating is read from Table 2-2.3 — not from Table 2-2.2, which holds F316 and F316H. The 2-2.3 table stops at 454 °C because note (1) limits every specification in the group to that temperature.
Can a Group 2.2 flange use Group 2.1 ratings?
No. A rating belongs to the material group printed against the grade in Table 1.1-1, and each group is tabulated separately because the allowable stresses differ. F316 and F316H are Group 2.2 and are read from Table 2-2.2; F304 and F304H are Group 2.1 and are read from Table 2-2.1. A joint that mixes two groups is rated at the lower of the two flange ratings (para. 2.3.2).