Steel A369 FP12
ASTM A369 FP12
A369 FP12 is a 1Cr-0.5Mo forged and bored alloy steel pipe to ASTM A369, the forged equivalent of A335 P12 seamless pipe.
Reference datasheet — A369 FP12 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the N+T condition
A369 FP12 tempers and conditions
A369 FP12 is supplied in 3 conditions, soft to hard. N+T is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Pick the softest state, 130 HB, for forged fitting blanks needing heavy machining or cold bending, accepting 255 MPa yield and a 540 °C service limit. | 255 | 455 | 35 | 130 HB | — |
N+TDefault Normalized and tempered | Choose the usual delivery condition for forged heat-resistant piping: normalized and tempered for 320 MPa yield, 30% elongation and creep capability to 550 °C. | 320 | 510 | 30 | 150 HB | — |
Quenched and tempered | Specify this non-standard but negotiable condition when thick-wall forged pipe needs 430 MPa room-temperature yield; high-temperature creep is no better than normalized and tempered. | 430 | 585 | 24 | 12 HRC | 7.5 % IACS |
Supply forms, finishes and certifications
Ways A369 FP12 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ISO-A | Isothermally annealed | Certification |
What is A369 FP12?
A369 FP12 is a 1Cr-0.5Mo forged and bored alloy steel pipe to ASTM A369, the forged equivalent of A335 P12 seamless pipe. Engineers specify it for high-temperature steam and process piping up to 550 °C; it is stocked normalized and tempered, annealed, ISO-annealed or quenched and tempered, with 320 MPa yield, 510 MPa tensile, 30% elongation and about 150 HB (80 HRB) in the default condition. Welding requires preheat and post-weld tempering, and the steel has no passive film, so external coating or insulation is mandatory. For higher temperature or sulfidation service, step up to FP22 or FP5. A369 FP12 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). A369 FP12 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 81% of steel grades. Elongation at break is 30% and the elastic modulus is 207 GPa (30 Msi).
What is A369 FP12 used for?
- Power plant high-temperature steam piping
- Process piping headers
- Boiler connecting and reheat lines
- Forged pipe fittings and nozzles for Cr-Mo systems
- Superheater outlet piping
- Petrochemical hot process lines
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 96% of steel grades
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
Limitations
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
A369 FP12 properties
Typical room-temperature values for A369 FP12-N+T; bars are the position among steel grades.
Physical3
A369 FP12 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical15
A369 FP12 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 81% of steel grades. Elongation at break is 30% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
A369 FP12 is rated for continuous service to 550°C (1,022 °F). It conducts heat at 41 W/m·K (23.7 BTU/hr·ft·°F), worse than 62% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
A369 FP12 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of A369 FP12 takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability6
A369 FP12's machinability is good (55/100, better than 62% of steel grades); weldability good (62/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. A369 FP12 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A369 FP12
Is A369 FP12 easy to machine?
Machinability in the annealed condition is about 60% of AISI 1212; use coated carbide, moderate cutting speed and ample coolant. Tool wear is slightly higher in the normalized-and-tempered condition.
Can A369 FP12 be welded?
Weld by GTAW/SMAW with E8018-B2 or ER80S-B2 filler, preheating to 150–250 °C. Temper/stress-relieve at 690–740 °C after welding to prevent cracking in the hardened heat-affected zone.
Can A369 FP12 be formed, bent or molded?
Hot bending and hot forming at 900–1000 °C are preferred for heavy-wall pipe; cold-bent pipe must be re-normalized and tempered to restore the microstructure.
A369 FP12 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 | 0.1 |
| Mn | 0.3 – 0.61 | 0.45 |
| Simax only | ≤ 0.5 | 0.25 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 0.8 – 1.25 | 1 |
| Mo | 0.44 – 0.65 | 0.55 |
| Fe | balance |
What surface finishes work on A369 FP12?
No self-passivating capability: blast the outside surface and apply a high-temperature protective coating or aluminize it. Bores are normally left in the as-machined condition.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel A369 FP12 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- A335 P12
How much does A369 FP12 cost?
A369 FP12 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
A369 FP12 — frequently asked
What is A369 FP12 used for?
A369 FP12 is typically used for power plant high-temperature steam piping, process piping headers, boiler connecting and reheat lines, forged pipe fittings and nozzles for Cr-Mo systems, superheater outlet piping and petrochemical hot process lines. In short: entry-level Cr-Mo creep pipe; forged equivalent of P12; weldable to 550 °C service.
What is the yield strength of A369 FP12?
A369 FP12 has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A369 FP12 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machinability in the annealed condition is about 60% of AISI 1212; use coated carbide, moderate cutting speed and ample coolant. Tool wear is slightly higher in the normalized-and-tempered condition.
Can A369 FP12 be welded?
Yes — weldability is rated good (62/100). Weld by GTAW/SMAW with E8018-B2 or ER80S-B2 filler, preheating to 150–250 °C. Temper/stress-relieve at 690–740 °C after welding to prevent cracking in the hardened heat-affected zone.
What surface finishes work on A369 FP12?
No self-passivating capability: blast the outside surface and apply a high-temperature protective coating or aluminize it. Bores are normally left in the as-machined condition.
Can A369 FP12 be formed, bent or molded?
Hot bending and hot forming at 900–1000 °C are preferred for heavy-wall pipe; cold-bent pipe must be re-normalized and tempered to restore the microstructure.
What is the maximum service temperature of A369 FP12?
A369 FP12 is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A369 FP12 N+T and A369 FP12-A?
N+T is the default condition — choose the usual delivery condition for forged heat-resistant piping: normalized and tempered for 320 MPa yield, 30% elongation and creep capability to 550 °C. A: pick the softest state, 130 HB, for forged fitting blanks needing heavy machining or cold bending, accepting 255 MPa yield and a 540 °C service limit. Yield strength is 320 MPa in N+T versus 255 MPa in A.
How much does A369 FP12 cost?
A369 FP12 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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 (P12) — ASTM International (2022)
- ASME BPVC Section II Part D — Materials Properties — ASME (2023)
- ASM Handbook Vol.1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- GB/T 5310 — (15CrMo) — SAC (2017)
- Mysteel/SMM (2025)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.