Steel SCr440-A vs SCr440 QT28-32
Steel · SCr440 temper comparison
SCr440-A and SCr440 QT28-32 are two conditions of the same steel grade, SCr440: A (solution annealed) versus QT28-32 (Q&T 28–32 HRC). The chemistry is identical, so every difference below comes from the condition. SCr440 QT28-32 is the stronger of the two: yield strength 830 MPa (120 ksi) against 420 MPa (60.9 ksi) for SCr440-A, about 98% more; tensile strength follows at 1,000 MPa (145 ksi) vs 655 MPa (95 ksi). In exchange, SCr440-A is the more ductile: elongation 26% versus 17% for SCr440 QT28-32, and SCr440 QT28-32 is harder (285 HB vs 197 HB). On the shop floor, SCr440-A machines more easily (good vs fair) and SCr440-A welds better (45 vs 35 out of 100).
SCr440-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
SCr440 QT28-32Choose it when strength drives the design.
SCr440-A vs SCr440 QT28-32: 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
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 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 57%
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 473 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 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 20 / 100 · Brazeability / Solderability 50 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 50 L/kg6 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.
SCr440-A vs SCr440 QT28-32 — frequently asked
Is SCr440 QT28-32 stronger than SCr440-A?
Yes. SCr440 QT28-32 has a typical yield strength of 830 MPa (120 ksi) against 420 MPa (60.9 ksi) for SCr440-A — about 98% more. Tensile strength is 1,000 MPa (145 ksi) vs 655 MPa (95 ksi).
Which condition does FabDigit quote by default, A or QT28-32?
QT is the default SCr440 condition in the FabDigit quote flow (neither A nor QT28-32). 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, SCr440-A or SCr440 QT28-32?
SCr440-A. Its machinability rates good (58/100) against fair (47/100) for SCr440 QT28-32; for welding the order is SCr440-A first (fair, 45/100) then SCr440 QT28-32 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in SCr440-A and SCr440 QT28-32 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.