Steel 30CrMnSiA-QT1470 vs 30CrMnSiA-SR
Steel · 30CrMnSiA temper comparison
30CrMnSiA-QT1470 and 30CrMnSiA-SR are two conditions of the same steel grade, 30CrMnSiA: QT1470 (Q&T high strength) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. 30CrMnSiA-QT1470 is the stronger of the two: yield strength 1,350 MPa (196 ksi) against 500 MPa (72.5 ksi) for 30CrMnSiA-SR, about 170% more; tensile strength follows at 1,560 MPa (226 ksi) vs 750 MPa (109 ksi). In exchange, 30CrMnSiA-SR is the more ductile: elongation 18% versus 8% for 30CrMnSiA-QT1470, and 30CrMnSiA-QT1470 is harder (340 HB vs 230 HB). 30CrMnSiA-SR runs hotter in service (400°C vs 200°C continuous). On the shop floor, 30CrMnSiA-SR machines more easily (fair vs poor) and 30CrMnSiA-SR welds better (good vs fair).
30CrMnSiA-QT1470Choose it when strength drives the design.
30CrMnSiA-SRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
30CrMnSiA-QT1470 vs 30CrMnSiA-SR: 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 165 GPa23.9 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 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 480 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.3 µm/m·K6.3 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 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: Brazeability / Solderability 55 / 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) 2.4 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.
30CrMnSiA-QT1470 vs 30CrMnSiA-SR — frequently asked
Is 30CrMnSiA-QT1470 stronger than 30CrMnSiA-SR?
Yes. 30CrMnSiA-QT1470 has a typical yield strength of 1,350 MPa (196 ksi) against 500 MPa (72.5 ksi) for 30CrMnSiA-SR — about 170% more. Tensile strength is 1,560 MPa (226 ksi) vs 750 MPa (109 ksi).
Which condition does FabDigit quote by default, QT1470 or SR?
QT1080 is the default 30CrMnSiA condition in the FabDigit quote flow (neither QT1470 nor SR). 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, 30CrMnSiA-QT1470 or 30CrMnSiA-SR?
30CrMnSiA-SR. Its machinability rates fair (50/100) against poor (25/100) for 30CrMnSiA-QT1470; for welding the order is 30CrMnSiA-SR first (good, 65/100) then 30CrMnSiA-QT1470 (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 30CrMnSiA-QT1470 and 30CrMnSiA-SR 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.