Steel SUP11A QT-40-45HRC vs SUP11A QT-48-52HRC
Steel · SUP11A temper comparison
SUP11A QT-40-45HRC and SUP11A QT-48-52HRC are two conditions of the same steel grade, SUP11A: QT-40-45HRC versus QT-48-52HRC. The chemistry is identical, so every difference below comes from the condition. SUP11A QT-48-52HRC is the stronger of the two: yield strength 1,520 MPa (220 ksi) against 1,180 MPa (171 ksi) for SUP11A QT-40-45HRC, about 29% more; tensile strength follows at 1,680 MPa (244 ksi) vs 1,330 MPa (193 ksi). In exchange, SUP11A QT-40-45HRC is the more ductile: elongation 11% versus 7% for SUP11A QT-48-52HRC, and SUP11A QT-48-52HRC is harder (480 HB vs 390 HB). SUP11A QT-40-45HRC runs hotter in service (250°C vs 180°C continuous).
SUP11A QT-40-45HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
SUP11A QT-48-52HRCChoose it when strength drives the design.
SUP11A QT-40-45HRC vs SUP11A QT-48-52HRC: 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.
SUP11A QT-40-45HRCSUP11A QT-48-52HRC
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
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 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
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 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 40 W/m·K23.1 BTU/hr·ft·°F · Specific Heat Capacity 470 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 · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % 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) -0.6 V · Corrosion Resistance 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Same in both: Machinability Rating (AISI 1212 = 100 %) 20% · Weldability 15 / 100 · Formability (cold) 12 / 100 · Brazeability / Solderability 25 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
SUP11A QT-40-45HRC vs SUP11A QT-48-52HRC — frequently asked
Is SUP11A QT-48-52HRC stronger than SUP11A QT-40-45HRC?
Yes. SUP11A QT-48-52HRC has a typical yield strength of 1,520 MPa (220 ksi) against 1,180 MPa (171 ksi) for SUP11A QT-40-45HRC — about 29% more. Tensile strength is 1,680 MPa (244 ksi) vs 1,330 MPa (193 ksi).
Which condition does FabDigit quote by default, QT-40-45HRC or QT-48-52HRC?
QT-SPRING is the default SUP11A condition in the FabDigit quote flow (neither QT-40-45HRC nor QT-48-52HRC). 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, SUP11A QT-40-45HRC or SUP11A QT-48-52HRC?
SUP11A QT-40-45HRC, by a small margin. Both rate poor for machinability — 22/100 against 15/100 for SUP11A QT-48-52HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SUP11A QT-40-45HRC and SUP11A QT-48-52HRC 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.