Steel A369 FP5 Annealed
Temper · default condition
ASTM A369 FP5
Default stock condition for FP5 forged-and-bored pipe: softest, best machinability and bendability, meets 415 MPa UTS / 205 MPa YS minima.
Values for the Annealed condition
Other A369 FP5 tempers and conditions
A369 FP5 is listed in 3 conditions; see the grade overview at A369 FP5.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefaultThis page full anneal per ASTM A369 (soften, ≤179 HB) | Default stock condition for FP5 forged-and-bored pipe: softest, best machinability and bendability, meets 415 MPa UTS / 205 MPa YS minima. | 305 | 500 | 30 | 150 HB | — |
Normalized and tempered | Pick when higher strength, finer grain and better creep/impact performance are wanted for pressure piping and furnace headers. | 400 | 585 | 24 | 175 HB | — |
Quenched and tempered | Special-order condition for thick FP5 forgings/valve bodies needing maximum toughness and through-thickness uniform strength; requires temper well above expected service temperature. | 480 | 640 | 21 | 15 HRC | 2.8 % IACS |
What is A369 FP5 Annealed?
A369 FP5 Annealed is A369 FP5 in the Annealed temper — default stock condition for FP5 forged-and-bored pipe: softest, best machinability and bendability, meets 415 MPa UTS / 205 MPa YS minima. A369 FP5 Annealed has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of steel grades. Elongation at break is 30% and the elastic modulus is 213 GPa (30.9 Msi). A369 FP5 Annealed has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,450°C (2,642 °F).
Advantages
- High service temperature — 620°C (1,148 °F), better than 99% of steel grades
- Good corrosion resistance — 30/100, better than 95% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
Limitations
- Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
- Low strength — 305 MPa (44.2 ksi), worse than 84% of steel grades
A369 FP5 Annealed properties
Typical room-temperature values for A369 FP5 Annealed; 12 are specific to this condition. Other listed values are A369 FP5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A369 FP5 Annealed has a density of 7.78 g/cm³ (0.281 lb/in³), lighter than 91% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
A369 FP5 Annealed has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of steel grades. Elongation at break is 30% and the elastic modulus is 213 GPa (30.9 Msi).
Thermal6
A369 FP5 Annealed is rated for continuous service to 620°C (1,148 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
A369 FP5 Annealed conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 95% of steel grades.
Sustainability4
Producing a kilogram of A369 FP5 Annealed takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
A369 FP5 Annealed's machinability is fair (52/100, better than 52% of steel grades); weldability fair (45/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A369 FP5 Annealed
Is A369 FP5 easy to machine?
Machine in the annealed condition with rigid setups, carbide tooling and moderate speeds (~60–90 m/min); the chromium carbides are abrasive and the steel work-hardens if feeds are too light.
Can A369 FP5 be welded?
Weld with matching 5Cr-0.5Mo filler (E8018-B6 / ER80S-B6), preheat and interpass 200–260 °C, and PWHT 700–760 °C — the alloy air-hardens and cold-cracks readily without it.
Can A369 FP5 be formed, bent or molded?
Bend and expand hot (900–1050 °C) whenever possible; cold bending is limited and must be followed by a stress-relief or full re-heat-treatment.
What surface finishes work on A369 FP5?
Not anodizable; protect with high-temperature aluminium/silicone paint, aluminizing or chromizing, and keep insulation dry to avoid corrosion under insulation.
A369 FP5 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C0.15 % max per ASTM A369/A335 grade P5 | ≤ 0.15 | 0.12 |
| Mn | 0.3 – 0.6 | 0.45 |
| SiFP5b variant runs 1.00–2.00 Si | ≤ 0.5 | 0.3 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Cr | 4 – 6 | 5 |
| Mo | 0.45 – 0.65 | 0.55 |
| Fe | balance | — |
A369 FP5 Annealed — frequently asked
What is A369 FP5 Annealed used for?
A369 FP5 Annealed is typically used for refinery hydroprocessing piping, high-temperature process piping, hot sulfidic gas oil and naphtha lines, catalytic reformer piping, fired heater outlet and transfer piping and forged fittings for 5Cr-0.5Mo systems. In short: 5Cr for sulfidic service; rated to 620 °C; air-hardening Cr-Mo pipe.
What is the yield strength of A369 FP5 Annealed?
A369 FP5 Annealed has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A369 FP5 Annealed easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machine in the annealed condition with rigid setups, carbide tooling and moderate speeds (~60–90 m/min); the chromium carbides are abrasive and the steel work-hardens if feeds are too light.
Can A369 FP5 Annealed be welded?
With care — weldability is rated fair (45/100). Weld with matching 5Cr-0.5Mo filler (E8018-B6 / ER80S-B6), preheat and interpass 200–260 °C, and PWHT 700–760 °C — the alloy air-hardens and cold-cracks readily without it.
What surface finishes work on A369 FP5 Annealed?
Not anodizable; protect with high-temperature aluminium/silicone paint, aluminizing or chromizing, and keep insulation dry to avoid corrosion under insulation.
Can A369 FP5 Annealed be formed, bent or molded?
Bend and expand hot (900–1050 °C) whenever possible; cold bending is limited and must be followed by a stress-relief or full re-heat-treatment.
What is the maximum service temperature of A369 FP5 Annealed?
A369 FP5 Annealed is rated for continuous use to about 620°C (1,148 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A369/A369M — Carbon and Ferritic Alloy Steel Forged and Bored Pipe for High-Temperature Service — ASTM International (2018)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (Grade P5) — ASTM International (2022)
- EN 10216-2 / DIN 17175 — X12CrMo5 (1.7362) seamless tubes — CEN / DIN (2020)
- GB/T 9948 — (12Cr5MoI) — SAC (2013)
- ASME BPVC Section II Part D — Material Properties (5Cr-0.5Mo) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- API 941 — Steels for Hydrogen Service at Elevated Temperatures — API (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.