Steel SCM425-HR vs SCM425 QT-28-32HRC
Steel · SCM425 temper comparison
SCM425-HR and SCM425 QT-28-32HRC are two conditions of the same steel grade, SCM425: HR (hot rolled) versus QT-28-32HRC. The chemistry is identical, so every difference below comes from the condition. SCM425 QT-28-32HRC is the stronger of the two: yield strength 810 MPa (117 ksi) against 460 MPa (66.7 ksi) for SCM425-HR, about 76% more; tensile strength follows at 950 MPa (138 ksi) vs 720 MPa (104 ksi). In exchange, SCM425-HR is the more ductile: elongation 19% versus 16% for SCM425 QT-28-32HRC, and SCM425 QT-28-32HRC is harder (285 HB vs 207 HB).
SCM425-HRChoose it when the part is bent, formed or impact-loaded.
SCM425 QT-28-32HRCChoose it when strength drives the design.
SCM425-HR vs SCM425 QT-28-32HRC: 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
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 206 GPa29.9 Msi · Shear Modulus 80 GPa11.6 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 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 42 W/m·K24.3 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 · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 2.3×10⁻⁷ Ω·m9.06 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 %)
Formability (cold)
Same in both: Weldability 40 / 100 · Brazeability / Solderability 60 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
SCM425-HR vs SCM425 QT-28-32HRC — frequently asked
Is SCM425 QT-28-32HRC stronger than SCM425-HR?
Yes. SCM425 QT-28-32HRC has a typical yield strength of 810 MPa (117 ksi) against 460 MPa (66.7 ksi) for SCM425-HR — about 76% more. Tensile strength is 950 MPa (138 ksi) vs 720 MPa (104 ksi).
Which condition does FabDigit quote by default, HR or QT-28-32HRC?
A is the default SCM425 condition in the FabDigit quote flow (neither HR nor QT-28-32HRC). 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, SCM425-HR or SCM425 QT-28-32HRC?
SCM425-HR, by a small margin. Both rate fair for machinability — 50/100 against 42/100 for SCM425 QT-28-32HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SCM425-HR and SCM425 QT-28-32HRC 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.