Steel SUP12 QT44-48 vs SUP12 QT48-52
Steel · SUP12 temper comparison
SUP12 QT44-48 and SUP12 QT48-52 are two conditions of the same steel grade, SUP12: QT44-48 (Q&T 44–48 HRC) versus QT48-52 (Q&T 48–52 HRC). The chemistry is identical, so every difference below comes from the condition. SUP12 QT48-52 is the stronger of the two: yield strength 1,780 MPa (258 ksi) against 1,620 MPa (235 ksi) for SUP12 QT44-48, about 10% more; tensile strength follows at 1,980 MPa (287 ksi) vs 1,800 MPa (261 ksi). In exchange, SUP12 QT44-48 is the more ductile: elongation 9% versus 6% for SUP12 QT48-52, and SUP12 QT48-52 is harder (50 HRC vs 47 HRC). SUP12 QT44-48 runs hotter in service (250°C vs 200°C continuous).
SUP12 QT44-48Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
SUP12 QT48-52Choose it when strength drives the design.
SUP12 QT44-48 vs SUP12 QT48-52: 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
Reduction in Area
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
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 · Compressive Strength 1,700 MPa247 ksi · Shear Strength 1,080 MPa157 ksi · Fracture Toughness (K_IC) 45 MPa·√m41 ksi·√in · Hardness, Brinell 455 HB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,460°C2,660 °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) 11.5 µm/m·K6.4 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 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 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 %)
Same in both: Weldability 12 / 100 · Formability (cold) 10 / 100 · Castability 35 / 100 · Brazeability / Solderability 25 / 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 40 L/kg4.8 gal/lb · Typical Recycled Content 25%
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.
SUP12 QT44-48 vs SUP12 QT48-52 — frequently asked
Is SUP12 QT48-52 stronger than SUP12 QT44-48?
Yes. SUP12 QT48-52 has a typical yield strength of 1,780 MPa (258 ksi) against 1,620 MPa (235 ksi) for SUP12 QT44-48 — about 10% more. Tensile strength is 1,980 MPa (287 ksi) vs 1,800 MPa (261 ksi).
Which condition does FabDigit quote by default, QT44-48 or QT48-52?
QT44-48 is the default SUP12 condition in the FabDigit quote flow. 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, SUP12 QT44-48 or SUP12 QT48-52?
SUP12 QT44-48. Its machinability rates poor (15/100) against not recommended (10/100) for SUP12 QT48-52.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SUP12 QT44-48 and SUP12 QT48-52 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.