Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
5% Chromium – 0.5% Molybdenum forged alloy steel flanges for refinery heaters, hydrocracker and hot hydrogen service.
Tubewell Steel & Engg. Co. manufactures, stocks and supplies ASTM A182 F5 and F5a flanges from Mumbai, India. With 4–6% chromium and 0.5% molybdenum, F5 delivers far better resistance to sulphidation and hydrogen attack than low-chrome grades, making it the standard flange choice for A335 P5 refinery heater and hydrocracker piping.
Why F5 flanges are specified for hot, sulphur-bearing hydrocarbon service
ASTM A182 F5 is a 5% chromium – 0.5% molybdenum ferritic alloy steel used for forged flanges, fittings and valve parts. The higher chromium content forms a protective oxide that resists high-temperature sulphidic corrosion and oxidation, while molybdenum provides creep strength and reduces temper embrittlement. The companion grade F5a has a higher carbon limit and delivers a minimum tensile strength of 620 MPa for higher-strength designs.
Our F5 flanges are forged from certified billets, annealed or normalized and tempered at a minimum of 675°C as required by ASTM A182, and then CNC machined to ASME B16.5, B16.47 or EN 1092-1. Bores are matched to the mating A335 P5 pipe schedule and every flange carries a heat number for traceability. EN 10204 3.1 certificates are standard; 3.2 certification and third-party inspection by TÜV, BV, SGS or Lloyd's are available on request.
Standard supply range for ASTM A182 F5 flanges
| Parameter | Details |
|---|---|
| Material Standard | ASTM A182, ASME SA182 |
| Grade | F5 (UNS K41545), F5a (UNS K42544) |
| Dimension Standard | ASME B16.5 (1/2" – 24"), ASME B16.47 Series A & B (26" – 48"), MSS SP-44, EN 1092-1 |
| Size | 1/2" NB to 48" NB (DN 15 – DN 1200) |
| Pressure Class | ASME Class 150, 300, 600, 900, 1500, 2500 |
| PN Rating | PN6, PN10, PN16, PN25, PN40, PN64 |
| Flange Types | Weld Neck, Slip-On, Blind, Socket Weld, Threaded, Lap Joint, RTJ, Long Weld Neck, Orifice, Spectacle Blind |
| Facing | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove |
| Face Finish | Serrated 125 – 250 µin Ra (3.2 – 6.3 µm), smooth finish on request |
| Bore / Schedule | SCH 10 to SCH XXS, to match A335 P5 pipe |
| Heat Treatment | Annealed or Normalized & Tempered (tempering min. 675°C / 1250°F) |
| B16.5 Material Group | Group 1.13 (5Cr-½Mo) |
| Testing | PMI, Hardness, Tensile, Impact, UT, MPI / DPT, Visual & Dimensional |
| Certificates | EN 10204 3.1 / 3.2, IBR Certification, TPI Reports |
International equivalents of A182 F5
| Grade | ASTM / ASME | UNS | EN 10222-2 | W.Nr. | JIS G3203 | Nominal |
|---|---|---|---|---|---|---|
| F5 | A182 F5 / SA182 F5 | K41545 | X16CrMo5-1 | 1.7366 | SFVAF5B | 5Cr-0.5Mo |
| F5a | A182 F5a / SA182 F5a | K42544 | – | – | – | 5Cr-0.5Mo (high C) |
Equivalents are the nearest comparable grades for reference; confirm suitability against the governing design code before substitution.
Weight %, as per ASTM A182
| Grade | C | Mn | P | S | Si | Ni | Cr | Mo |
|---|---|---|---|---|---|---|---|---|
| A182 F5 | 0.15 max | 0.30 – 0.60 | 0.030 max | 0.030 max | 0.50 max | 0.50 max | 4.0 – 6.0 | 0.44 – 0.65 |
| A182 F5a | 0.25 max | 0.60 max | 0.040 max | 0.030 max | 0.50 max | 0.50 max | 4.0 – 6.0 | 0.44 – 0.65 |
Minimum values at room temperature
| Grade | Tensile Strength | Yield Strength (0.2%) | Elongation (in 2") | Reduction of Area | Hardness (HBW) |
|---|---|---|---|---|---|
| A182 F5 | 485 MPa (70 ksi) min | 275 MPa (40 ksi) min | 20% min | 35% min | 143 – 217 |
| A182 F5a | 620 MPa (90 ksi) min | 450 MPa (65 ksi) min | 22% min | 50% min | 187 – 248 |
Typical values (for reference)
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.75 g/cm³ | 0.280 lb/in³ |
| Melting Range | 1450 – 1510 °C | 2640 – 2750 °F |
| Modulus of Elasticity | 210 GPa | 30.5 × 10³ ksi |
| Thermal Conductivity (100°C) | 33 W/m·K | 19.1 BTU/h·ft·°F |
| Mean Thermal Expansion (20–300°C) | 11.9 µm/m·°C | 6.6 µin/in·°F |
| Specific Heat | 0.46 J/g·°C | 0.11 BTU/lb·°F |
| Max. Service Temperature | ≈ 650 °C | ≈ 1200 °F |
ASME B16.5 Class 150 weld neck flanges – dimensions in mm
| NPS | Flange OD | Thickness | RF Dia | Bolt Circle | Bolts | Hub Dia X | Hub Length Y |
|---|---|---|---|---|---|---|---|
| 1/2" | 90 | 9.6 | 34.9 | 60.3 | 4 × 1/2" | 30 | 46 |
| 3/4" | 100 | 11.2 | 42.9 | 69.9 | 4 × 1/2" | 38 | 51 |
| 1" | 110 | 12.7 | 50.8 | 79.4 | 4 × 1/2" | 49 | 54 |
| 1 1/4" | 115 | 14.3 | 63.5 | 88.9 | 4 × 1/2" | 59 | 56 |
| 1 1/2" | 125 | 15.9 | 73.0 | 98.4 | 4 × 1/2" | 65 | 60 |
| 2" | 150 | 17.5 | 92.1 | 120.7 | 4 × 5/8" | 78 | 62 |
| 2 1/2" | 180 | 20.7 | 104.8 | 139.7 | 4 × 5/8" | 90 | 68 |
| 3" | 190 | 22.3 | 127.0 | 152.4 | 4 × 5/8" | 108 | 68 |
| 4" | 230 | 22.3 | 157.2 | 190.5 | 8 × 5/8" | 135 | 75 |
| 5" | 255 | 22.3 | 185.7 | 215.9 | 8 × 3/4" | 164 | 87 |
| 6" | 280 | 23.9 | 215.9 | 241.3 | 8 × 3/4" | 192 | 87 |
| 8" | 345 | 27.0 | 269.9 | 298.5 | 8 × 3/4" | 246 | 100 |
| 10" | 405 | 28.6 | 323.8 | 362.0 | 12 × 7/8" | 305 | 100 |
| 12" | 485 | 30.2 | 381.0 | 431.8 | 12 × 7/8" | 365 | 113 |
| 14" | 535 | 33.4 | 412.8 | 476.3 | 12 × 1" | 400 | 125 |
| 16" | 595 | 35.0 | 469.9 | 539.8 | 16 × 1" | 457 | 125 |
| 18" | 635 | 38.1 | 533.4 | 577.9 | 16 × 1 1/8" | 505 | 138 |
| 20" | 700 | 41.3 | 584.2 | 635.0 | 20 × 1 1/8" | 559 | 143 |
| 24" | 815 | 46.1 | 692.2 | 749.3 | 20 × 1 1/4" | 663 | 151 |
Thickness = minimum flange thickness excluding 2 mm (0.06") raised face. Hub Dia X = hub diameter at base, Hub Length Y = length through hub of weld neck flange. All dimensions in mm.
Where ASTM A182 F5 flanges are used
Crude and vacuum heater transfer lines carrying hot, sulphur-rich oil.
Reactor effluent and hydrogen-rich lines prone to hydrogen attack.
Coker heater outlets and transfer piping at high temperature.
Cracking furnaces and reformer piping in petrochemical complexes.
Channel and nozzle flanges on high-temperature exchangers.
Steam and process connections in captive and utility power plants.
Quality you can verify on every heat
Large inventory for fast dispatch
MTC EN 10204 3.1 / 3.2
Positive material identification
Pan-India & export shipping
Quick answers about A182 F5 flanges
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