Steel A182 F11 Cl.1 P11-NT
Finish state
ASTM A182 F11 Cl.1 · UNS K11597
P11-NT = a335 P11 pipe
Choose when the same 1.25Cr-0.5Mo chemistry is bought as seamless high-temperature piping rather than forgings.
Values for the P11-NT condition
Other A182 F11 Cl.1 tempers and conditions
A182 F11 Cl.1 is listed in 4 conditions; see the grade overview at A182 F11 Cl.1.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard supply condition for F11 Cl.1 forgings, flanges and fittings where maximum weldability/softness (≤121 HB) is wanted and only the 415 MPa strength class is required. | 275 | 480 | 30 | 115 HB | — |
P11-NTThis page A335 P11 pipe | Choose when the same 1.25Cr-0.5Mo chemistry is bought as seamless high-temperature piping rather than forgings. | 290 | 490 | 30 | 145 HB | 7.8 % IACS |
Class 2 | Pick when the piping class calls for the 485 MPa / 275 MPa strength grade of F11 (most common F11 class in refinery valves and fittings). | 380 | 550 | 25 | 170 HB | — |
Class 3 | Used where 515 MPa / 310 MPa minimums are specified for heavy-wall F11 forgings; hardness still capped at 207 HB for wet-H2S service. | 415 | 580 | 24 | 180 HB | — |
What is A182 F11 Cl.1 P11-NT?
A182 F11 Cl.1 P11-NT is A182 F11 Cl.1 supplied in the P11-NT condition — choose when the same 1.25Cr-0.5Mo chemistry is bought as seamless high-temperature piping rather than forgings. A182 F11 Cl.1 P11-NT has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 88% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi). A182 F11 Cl.1 P11-NT has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,450°C (2,642 °F). ANN is the default condition FabDigit quotes; P11-NT is available on request or by drawing note.
Advantages
- High service temperature — 593°C (1,099 °F), better than 97% of steel grades
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 94% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
Limitations
- Low strength — 290 MPa (42.1 ksi), worse than 88% of steel grades
A182 F11 Cl.1 P11-NT properties
Typical room-temperature values for A182 F11 Cl.1 P11-NT; 22 are specific to this condition. Other listed values are A182 F11 Cl.1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A182 F11 Cl.1 P11-NT has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
A182 F11 Cl.1 P11-NT has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 88% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
A182 F11 Cl.1 P11-NT is rated for continuous service to 593°C (1,099 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
A182 F11 Cl.1 P11-NT conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (20/100), better than 87% of steel grades.
Sustainability4
Producing a kilogram of A182 F11 Cl.1 P11-NT takes about 31 MJ of energy and emits 2.2 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
A182 F11 Cl.1 P11-NT's machinability is good (55/100, better than 62% of steel grades); weldability good (55/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A182 F11 Cl.1 P11-NT
Is A182 F11 Cl.1 easy to machine?
Annealed Cl.1 machines readily at ~60 % of AISI 1212 with carbide or HSS tooling; low hardness gives gummy chips, so use positive rake, ample coolant and higher feeds.
Can A182 F11 Cl.1 be welded?
P-No.4 material: weld with matching E/ER 80S-B2 (or B2L) consumables, preheat 150–250 °C, interpass ≤315 °C and PWHT 700–760 °C to restore toughness and avoid hard HAZ.
Can A182 F11 Cl.1 be formed, bent or molded?
Hot forge at 1050–1200 °C, finish above 900 °C, then full anneal (~900 °C, furnace cool) for Cl.1; cold bending is possible but limited by 1.25Cr-0.5Mo work hardening.
What surface finishes work on A182 F11 Cl.1?
No anodizing; protect with shop primer, phosphating or aluminized/painted systems for atmospheric service, and use high-temperature coatings or insulation under hot piping to limit CUI.
A182 F11 Cl.1 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 |
|---|---|---|
| C | 0.05 – 0.15 | 0.12 |
| Mn | 0.3 – 0.6 | 0.45 |
| Si | 0.5 – 1 | 0.7 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 1 – 1.5 | 1.25 |
| Mo | 0.44 – 0.65 | 0.55 |
| Fe | balance | — |
A182 F11 Cl.1 P11-NT — frequently asked
What is A182 F11 Cl.1 P11-NT used for?
A182 F11 Cl.1 P11-NT is typically used for high-temperature flanges, valve bodies and refinery piping fittings. In short: softest 1.25Cr-0.5Mo forging class; creep service to 580 °C; easier machining than Cl.2.
What is the yield strength of A182 F11 Cl.1 P11-NT?
A182 F11 Cl.1 P11-NT has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 88% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A182 F11 Cl.1 P11-NT easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Annealed Cl.1 machines readily at ~60 % of AISI 1212 with carbide or HSS tooling; low hardness gives gummy chips, so use positive rake, ample coolant and higher feeds.
Can A182 F11 Cl.1 P11-NT be welded?
Yes — weldability is rated good (55/100). P-No.4 material: weld with matching E/ER 80S-B2 (or B2L) consumables, preheat 150–250 °C, interpass ≤315 °C and PWHT 700–760 °C to restore toughness and avoid hard HAZ.
What surface finishes work on A182 F11 Cl.1 P11-NT?
No anodizing; protect with shop primer, phosphating or aluminized/painted systems for atmospheric service, and use high-temperature coatings or insulation under hot piping to limit CUI.
Can A182 F11 Cl.1 P11-NT be formed, bent or molded?
Hot forge at 1050–1200 °C, finish above 900 °C, then full anneal (~900 °C, furnace cool) for Cl.1; cold bending is possible but limited by 1.25Cr-0.5Mo work hardening.
What is the maximum service temperature of A182 F11 Cl.1 P11-NT?
A182 F11 Cl.1 P11-NT is rated for continuous use to about 593°C (1,099 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A182 F11 Cl.1-ANN and A182 F11 Cl.1 NT-CL3?
ANN is the default condition — standard supply condition for F11 Cl.1 forgings, flanges and fittings where maximum weldability/softness (≤121 HB) is wanted and only the 415 MPa strength class is required. NT-CL3: used where 515 MPa / 310 MPa minimums are specified for heavy-wall F11 forgings; hardness still capped at 207 HB for wet-H2S service. Yield strength is 275 MPa in ANN versus 415 MPa in NT-CL3.
Sources
- ASTM A182/A182M — Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Fittings, Valves and Parts for High-Temperature Service — ASTM International (2023)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (P11) — ASTM International (2023)
- ASME BPVC Section II Part D — Materials, Properties (Metric) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- API RP 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.