ASTM A182 F11 / F22 Alloy Steel Flanges
Teshi Group manufactures ASTM A182 F11 / F22 Alloy Steel flanges (chrome-moly F11 Class 2, F22 Class 3, 1¼Cr-½Mo, 2¼Cr-1Mo) as an OEM in India — forged, machined, marked and certified in-house to ASME B16.5, ASME B16.47, EN 1092-1 and customer drawings.
Chromium–molybdenum steels keep their strength and resist creep and hydrogen attack at high temperature, which makes them standard for steam, boiler, refinery heater and hot-blast service.
ASTM A182 F11 / F22 Alloy Steel flanges at a glance
| Material | ASTM A182 F11 / F22 Alloy Steel |
|---|---|
| Specification | ASTM A182 F11 Cl.2 / ASTM A182 F22 Cl.3 |
| UNS / W.Nr. | K11572 / 1.7335 · K21590 / 1.7380 |
| Sizes | NPS ½"–24" (ASME B16.5), 26"–60" (ASME B16.47 A / B), DN 10–600 (EN 1092-1) |
| Pressure class | Class 150, 300, 600, 900, 1500, 2500 · PN 6–40 |
| Facing / ends | RF, FF, RTJ, tongue & groove, male-female; serrated or smooth finish |
| Certification | EN 10204 3.1 standard · 3.2 with third-party inspection · IBR on request |
| Testing | PMI, hardness, dimensional; UT, IGC, impact and ferrite as specified |
ASTM A182 F11 / F22 Alloy Steel chemistry and mechanical properties
Chemical composition of ASTM A182 F11 / F22 Alloy Steel (weight %, maximum unless a range)
| Grade | C | Mn | Si | Cr | Mo |
|---|---|---|---|---|---|
| F11 Cl.2 (1¼Cr-½Mo) | 0.10–0.20 | 0.30–0.80 | 0.50–1.00 | 1.00–1.50 | 0.44–0.65 |
| F22 Cl.3 (2¼Cr-1Mo) | 0.05–0.15 | 0.30–0.60 | 0.50 | 2.00–2.50 | 0.87–1.13 |
Mechanical properties of ASTM A182 F11 / F22 Alloy Steel (minimum, room temperature)
| Grade | Tensile strength | Yield strength (0.2 %) | Elongation | Note |
|---|---|---|---|---|
| F11 Cl.2 (1¼Cr-½Mo) | 485 MPa (70 ksi) | 275 MPa (40 ksi) | 20 % | Steam lines |
| F22 Cl.3 (2¼Cr-1Mo) | 515 MPa (75 ksi) | 310 MPa (45 ksi) | 20 % | Boiler headers |
Matching specifications by product form
| Grade | Forged flanges & fittings | Butt weld fittings | Plate | Pipe |
|---|---|---|---|---|
| F11 Cl.2 (1¼Cr-½Mo)UNS K11572 · W.Nr. 1.7335 | ASTM A182 F11 Cl.2 | ASTM A234 WP11 Cl.1 | ASTM A387 Gr 11 | ASTM A335 P11 |
| F22 Cl.3 (2¼Cr-1Mo)UNS K21590 · W.Nr. 1.7380 | ASTM A182 F22 Cl.3 | ASTM A234 WP22 Cl.1 | ASTM A387 Gr 22 | ASTM A335 P22 |
Limits and minimums from the governing ASTM / ASME specifications, summarised for convenience; the current edition takes precedence.
Pressure rating
Pressure–temperature ratings of ASTM A182 F11 / F22 Alloy Steel flanges to ASME B16.5 (bar, gauge). Ratings apply to the flange; the joint rating also depends on bolting and gasket.
Material Group 1.9: A182 F11 Cl.2 (also A217 WC6)
| Temp.°C | Class 150bar | Class 300bar | Class 600bar | Class 900bar | Class 1500bar | Class 2500bar |
|---|---|---|---|---|---|---|
| −29 to 38 | 19.8 | 51.7 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 51.5 | 103.0 | 154.4 | 257.4 | 429.0 |
| 150 | 15.8 | 49.7 | 99.5 | 149.2 | 248.7 | 414.5 |
| 200 | 13.8 | 48.0 | 95.9 | 143.9 | 239.8 | 399.6 |
| 250 | 12.1 | 46.3 | 92.7 | 139.0 | 231.8 | 386.2 |
| 300 | 10.2 | 42.9 | 85.7 | 128.6 | 214.4 | 357.1 |
| 325 | 9.3 | 41.4 | 82.6 | 124.0 | 206.6 | 344.3 |
| 350 | 8.4 | 40.3 | 80.4 | 120.7 | 201.1 | 335.3 |
| 375 | 7.4 | 38.9 | 77.6 | 116.5 | 194.1 | 323.2 |
| 400 | 6.5 | 36.5 | 73.3 | 109.8 | 183.1 | 304.9 |
| 425 | 5.5 | 35.2 | 70.0 | 105.1 | 175.1 | 291.6 |
| 450 | 4.6 | 33.7 | 67.7 | 101.4 | 169.0 | 281.8 |
| 475 | 3.7 | 31.7 | 63.4 | 95.1 | 158.2 | 263.9 |
| 500 | 2.8 | 25.7 | 51.5 | 77.2 | 128.6 | 214.4 |
| 538 | 1.4 | 14.9 | 29.8 | 44.7 | 74.5 | 124.1 |
Material Group 1.10: A182 F22 Cl.3 (also A217 WC9)
| Temp.°C | Class 150bar | Class 300bar | Class 600bar | Class 900bar | Class 1500bar | Class 2500bar |
|---|---|---|---|---|---|---|
| −29 to 38 | 19.8 | 51.7 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 51.5 | 103.0 | 154.6 | 257.6 | 429.4 |
| 150 | 15.8 | 50.3 | 100.3 | 150.6 | 250.8 | 418.2 |
| 200 | 13.8 | 48.6 | 97.2 | 145.8 | 243.4 | 405.4 |
| 250 | 12.1 | 46.3 | 92.7 | 139.0 | 231.8 | 386.2 |
| 300 | 10.2 | 42.9 | 85.7 | 128.6 | 214.4 | 357.1 |
| 325 | 9.3 | 41.4 | 82.6 | 124.0 | 206.6 | 344.3 |
| 350 | 8.4 | 40.3 | 80.4 | 120.7 | 201.1 | 335.3 |
| 375 | 7.4 | 38.9 | 77.6 | 116.5 | 194.1 | 323.2 |
| 400 | 6.5 | 36.5 | 73.3 | 109.8 | 183.1 | 304.9 |
| 425 | 5.5 | 35.2 | 70.0 | 105.1 | 175.1 | 291.6 |
| 450 | 4.6 | 33.7 | 67.7 | 101.4 | 169.0 | 281.8 |
| 475 | 3.7 | 31.7 | 63.4 | 95.1 | 158.2 | 263.9 |
| 500 | 2.8 | 28.2 | 56.5 | 84.7 | 140.9 | 235.0 |
| 538 | 1.4 | 18.4 | 36.9 | 55.3 | 92.2 | 153.7 |
Types we manufacture
Dimension charts
Where ASTM A182 F11 / F22 Alloy Steel is used
- Boiler, superheater and steam headers (IBR)
- Supercritical and ultra-supercritical power plants (F91)
- Blast-furnace hot-blast stoves and mains
- Refinery heaters and hydrogen service
- Petrochemical high-temperature lines
Testing & certification
- Normalised and tempered with recorded furnace charts
- Hardness testing of every heat treatment lot
- UT and MPI as specified; PMI on every piece
- IBR Form III-C certification when specified
Related materials
FAQ
ASTM A182 F11 / F22 Alloy Steel flanges: common questions
What specification covers ASTM A182 F11 / F22 Alloy Steel flanges?
ASTM A182 F11 / F22 Alloy Steel flanges are forged to ASTM A182 F11 Cl.2 / ASTM A182 F22 Cl.3 and dimensioned to ASME B16.5, ASME B16.47 or EN 1092-1.
What is the chemical composition of F11 Cl.2 (1¼Cr-½Mo)?
F11 Cl.2 (1¼Cr-½Mo) (UNS K11572): C 0.10–0.20, Mn 0.30–0.80, Si 0.50–1.00, Cr 1.00–1.50, Mo 0.44–0.65 (weight %; single values are maximums).
What are the minimum mechanical properties of F11 Cl.2 (1¼Cr-½Mo)?
Tensile strength 485 MPa (70 ksi), yield strength 275 MPa (40 ksi), elongation 20 %.
Is Teshi Group a manufacturer of ASTM A182 F11 / F22 Alloy Steel flanges in India?
Yes. Teshi Group has manufactured flanges and fittings in India since 1971 and is ISO 9001:2015 certified and IBR approved. Every ASTM A182 F11 / F22 Alloy Steel piece is hard-stamped with its heat number and supplied with an EN 10204 3.1 certificate; 3.2 with third-party inspection on request.
Which chrome-moly grade is used for steam lines?
F11 (1¼Cr-½Mo) and F22 (2¼Cr-1Mo) are the common grades for steam and boiler lines; F91 (9Cr-1Mo-V) is used in supercritical and ultra-supercritical power plants for its creep strength.
How are F91 flanges heat treated?
F91 is normalised and tempered, typically normalised around 1040–1080 °C and tempered at 730–800 °C, with recorded furnace charts and hardness checks on every lot.
Chrome-moly alloy steel grade data sheets
Chrome-moly alloy steel overview →Chemical composition, mechanical properties and PDF data sheet for each grade.
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