Steel A369 Grade FPB-IA vs A369 Grade FPB-N
Steel · A369 Grade FPB temper comparison
A369 Grade FPB-IA and A369 Grade FPB-N are two conditions of the same steel grade, A369 Grade FPB: IA (isothermal annealed) versus N (normalized). The chemistry is identical, so every difference below comes from the condition. A369 Grade FPB-N is the stronger of the two: yield strength 295 MPa (42.8 ksi) against 265 MPa (38.4 ksi) for A369 Grade FPB-IA, about 11% more; tensile strength follows at 480 MPa (69.6 ksi) vs 450 MPa (65.3 ksi). A369 Grade FPB-N is harder — 147 HB against 135 HB for A369 Grade FPB-IA — which matters for wear surfaces and threads.
A369 Grade FPB-NChoose it when strength drives the design, or when surface hardness matters.
A369 Grade FPB-IA vs A369 Grade FPB-N: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
A369 Grade FPB-IAA369 Grade FPB-N
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,470°C2,678 °F · Liquidus Temperature 1,515°C2,759 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 52 W/m·K30 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 425°C797 °F · Min Service Temperature -29°C-20 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 55 / 100 · Brazeability / Solderability 70 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 25%
Strength versus weight
Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
A369 Grade FPB-IA vs A369 Grade FPB-N — frequently asked
Is A369 Grade FPB-N stronger than A369 Grade FPB-IA?
Yes. A369 Grade FPB-N has a typical yield strength of 295 MPa (42.8 ksi) against 265 MPa (38.4 ksi) for A369 Grade FPB-IA — about 11% more. Tensile strength is 480 MPa (69.6 ksi) vs 450 MPa (65.3 ksi).
Which condition does FabDigit quote by default, IA or N?
N is the default A369 Grade FPB condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
When should I choose A369 Grade FPB-IA over A369 Grade FPB-N?
Pick A369 Grade FPB-N when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in A369 Grade FPB-IA and A369 Grade FPB-N side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.