Stainless Steel 440C Hardened & Tempered vs 440C Stress Relieved
Stainless Steel · 440C temper comparison
440C Hardened & Tempered and 440C Stress Relieved are two conditions of the same stainless steel grade, 440C: Hardened & Tempered (quenched and tempered) versus Stress Relieved. The chemistry is identical, so every difference below comes from the condition. 440C Hardened & Tempered is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 470 MPa (68.2 ksi) for 440C Stress Relieved, about 4.0 times as much; tensile strength follows at 1,970 MPa (286 ksi) vs 780 MPa (113 ksi). In exchange, 440C Stress Relieved is the more ductile: elongation 13% versus 2% for 440C Hardened & Tempered, and 440C Hardened & Tempered is harder (580 HB vs 255 HB). 440C Stress Relieved runs hotter in service (425°C vs 250°C continuous). On the shop floor, 440C Stress Relieved machines more easily (fair vs not recommended).
440C Hardened & TemperedChoose it when strength drives the design.
440C Stress RelievedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
440C Hardened & Tempered vs 440C Stress Relieved: 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.
440C Hardened & Tempered440C Stress Relieved
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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28
Physical
Density and transition temperatures.
Same in both: Density 7.68 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 24.2 W/m·K14 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.2 µm/m·K5.7 µin/in·°F · Latent Heat of Fusion 265 J/g114 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
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)
Polishability
Same in both: Brazeability / Solderability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 4.3 kg CO₂/kg · Embodied Water 150 L/kg18 gal/lb · Typical Recycled Content 60%
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.
440C Hardened & Tempered vs 440C Stress Relieved — frequently asked
Is 440C Hardened & Tempered stronger than 440C Stress Relieved?
Yes. 440C Hardened & Tempered has a typical yield strength of 1,900 MPa (276 ksi) against 470 MPa (68.2 ksi) for 440C Stress Relieved — about 4.0 times as much. Tensile strength is 1,970 MPa (286 ksi) vs 780 MPa (113 ksi).
Which condition does FabDigit quote by default, Hardened & Tempered or Stress Relieved?
Annealed is the default 440C condition in the FabDigit quote flow (neither Hardened & Tempered nor Stress Relieved). 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, 440C Hardened & Tempered or 440C Stress Relieved?
440C Stress Relieved. Its machinability rates fair (43/100) against not recommended (10/100) for 440C Hardened & Tempered; for welding the order is 440C Stress Relieved first (not recommended, 12/100) then 440C Hardened & Tempered (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 440C Hardened & Tempered and 440C Stress Relieved 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.