Stainless Steel 440F-ACD vs 440F Hardened & Tempered
Stainless Steel · 440F temper comparison
440F-ACD and 440F Hardened & Tempered are two conditions of the same stainless steel grade, 440F: ACD (annealed and cold drawn bar) versus Hardened & Tempered (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 440F Hardened & Tempered is the stronger of the two: yield strength 1,720 MPa (249 ksi) against 620 MPa (89.9 ksi) for 440F-ACD, about 177% more; tensile strength follows at 1,860 MPa (270 ksi) vs 860 MPa (125 ksi). In exchange, 440F-ACD is the more ductile: elongation 8% versus 3% for 440F Hardened & Tempered, and 440F Hardened & Tempered is harder (580 HB vs 285 HB). 440F-ACD runs hotter in service (400°C vs 250°C continuous). On the shop floor, 440F-ACD machines more easily (good vs not recommended).
440F-ACDChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
440F Hardened & TemperedChoose it when strength drives the design.
440F-ACD vs 440F Hardened & Tempered: 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.
440F-ACD440F Hardened & Tempered
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, 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 0.28
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,425°C2,597 °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 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °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) -0.25 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 40 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 40%
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.
440F-ACD vs 440F Hardened & Tempered — frequently asked
Is 440F Hardened & Tempered stronger than 440F-ACD?
Yes. 440F Hardened & Tempered has a typical yield strength of 1,720 MPa (249 ksi) against 620 MPa (89.9 ksi) for 440F-ACD — about 177% more. Tensile strength is 1,860 MPa (270 ksi) vs 860 MPa (125 ksi).
Which condition does FabDigit quote by default, ACD or Hardened & Tempered?
Annealed is the default 440F condition in the FabDigit quote flow (neither ACD nor Hardened & Tempered). 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, 440F-ACD or 440F Hardened & Tempered?
440F-ACD. Its machinability rates good (57/100) against not recommended (12/100) for 440F Hardened & Tempered.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 440F-ACD and 440F Hardened & Tempered 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.