Stainless Steel 431 Annealed vs 431 Hardened
Stainless Steel · 431 temper comparison
431 Annealed and 431 Hardened are two conditions of the same stainless steel grade, 431: Annealed versus Hardened. The chemistry is identical, so every difference below comes from the condition. 431 Hardened is the stronger of the two: yield strength 1,200 MPa (174 ksi) against 655 MPa (95 ksi) for 431 Annealed, about 83% more; tensile strength follows at 1,500 MPa (218 ksi) vs 830 MPa (120 ksi). In exchange, 431 Annealed is the more ductile: elongation 22% versus 5% for 431 Hardened, and 431 Hardened is harder (440 HB vs 262 HB). 431 Annealed runs hotter in service (550°C vs 150°C continuous). On the shop floor, 431 Annealed machines more easily (fair vs not recommended) and 431 Annealed welds better (poor vs not recommended).
431 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
431 HardenedChoose it when strength drives the design.
431 Annealed vs 431 Hardened: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.75 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V
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: Brazeability / Solderability 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 4.2 kg CO₂/kg · Embodied Water 140 L/kg16.8 gal/lb · Typical Recycled Content 50%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
431 Annealed vs 431 Hardened — frequently asked
Is 431 Hardened stronger than 431 Annealed?
Yes. 431 Hardened has a typical yield strength of 1,200 MPa (174 ksi) against 655 MPa (95 ksi) for 431 Annealed — about 83% more. Tensile strength is 1,500 MPa (218 ksi) vs 830 MPa (120 ksi).
Which condition does FabDigit quote by default, Annealed or Hardened?
Hardened & Tempered is the default 431 condition in the FabDigit quote flow (neither Annealed nor Hardened). 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, 431 Annealed or 431 Hardened?
431 Annealed. Its machinability rates fair (42/100) against not recommended (10/100) for 431 Hardened; for welding the order is 431 Annealed first (poor, 25/100) then 431 Hardened (not recommended, 8/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 431 Annealed and 431 Hardened 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.