Steel P91-HR vs P91 Normalized
Steel · P91 temper comparison
P91-HR and P91 Normalized are two conditions of the same steel grade, P91: HR (hot rolled) versus Normalized. The chemistry is identical, so every difference below comes from the condition. P91 Normalized is the stronger of the two: yield strength 950 MPa (138 ksi) against 750 MPa (109 ksi) for P91-HR, about 27% more; tensile strength follows at 1,300 MPa (189 ksi) vs 1,000 MPa (145 ksi). In exchange, P91-HR is the more ductile: elongation 14% versus 10% for P91 Normalized, and P91 Normalized is harder (420 HB vs 330 HB).
P91-HRChoose it when the part is bent, formed or impact-loaded.
P91 NormalizedChoose it when strength drives the design.
P91-HR vs P91 Normalized: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 218 GPa31.6 Msi · Shear Modulus 84 GPa12.2 Msi · Bulk Modulus 170 GPa24.7 Msi · Poisson's Ratio 0.3 · Reduction in Area 45% · Compressive Strength 770 MPa112 ksi · Shear Strength 600 MPa87 ksi · Fatigue Strength (Endurance Limit) 430 MPa62.4 ksi · Fracture Toughness (K_IC) 40 MPa·√m36.4 ksi·√in · Hardness, Rockwell B 96 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.77 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 25 W/m·K14.4 BTU/hr·ft·°F · Specific Heat Capacity 480 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.9 µm/m·K6.1 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.4×10⁻⁷ Ω·m25.2 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 28 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 25% · Brazeability / Solderability 30 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.5 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 30%
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.
P91-HR vs P91 Normalized — frequently asked
Is P91 Normalized stronger than P91-HR?
Yes. P91 Normalized has a typical yield strength of 950 MPa (138 ksi) against 750 MPa (109 ksi) for P91-HR — about 27% more. Tensile strength is 1,300 MPa (189 ksi) vs 1,000 MPa (145 ksi).
Which condition does FabDigit quote by default, HR or Normalized?
HR is the default P91 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.
Which is easier to machine, P91-HR or P91 Normalized?
P91-HR, by a small margin. Both rate poor for machinability — 22/100 against 15/100 for P91 Normalized; for welding the order is P91 Normalized first (poor, 20/100) then P91-HR (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in P91-HR and P91 Normalized 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.