Steel 40CrMnMo-CD vs 40CrMnMo QT-28-32HRC
Steel · 40CrMnMo temper comparison
40CrMnMo-CD and 40CrMnMo QT-28-32HRC are two conditions of the same steel grade, 40CrMnMo: CD (cold drawn) versus QT-28-32HRC (Q&T 28–32 HRC (≈269–302 HB) pre-hardened block). The chemistry is identical, so every difference below comes from the condition. 40CrMnMo QT-28-32HRC is the stronger of the two: yield strength 820 MPa (119 ksi) against 720 MPa (104 ksi) for 40CrMnMo-CD, about 14% more; tensile strength follows at 980 MPa (142 ksi) vs 860 MPa (125 ksi). 40CrMnMo QT-28-32HRC is the more ductile: elongation 15% versus 10% for 40CrMnMo-CD, and 40CrMnMo QT-28-32HRC is harder (285 HB vs 255 HB). 40CrMnMo QT-28-32HRC runs hotter in service (400°C vs 350°C continuous).
40CrMnMo QT-28-32HRCChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
40CrMnMo-CD vs 40CrMnMo 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.
40CrMnMo-CD40CrMnMo QT-28-32HRC
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 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 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
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 · 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) -0.6 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)
Polishability
Same in both: Brazeability / Solderability 50 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 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.
40CrMnMo-CD vs 40CrMnMo QT-28-32HRC — frequently asked
Is 40CrMnMo QT-28-32HRC stronger than 40CrMnMo-CD?
Yes. 40CrMnMo QT-28-32HRC has a typical yield strength of 820 MPa (119 ksi) against 720 MPa (104 ksi) for 40CrMnMo-CD — about 14% more. Tensile strength is 980 MPa (142 ksi) vs 860 MPa (125 ksi).
Which condition does FabDigit quote by default, CD or QT-28-32HRC?
QT600 is the default 40CrMnMo condition in the FabDigit quote flow (neither CD 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, 40CrMnMo-CD or 40CrMnMo QT-28-32HRC?
40CrMnMo-CD. Its machinability rates good (60/100) against fair (54/100) for 40CrMnMo QT-28-32HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 40CrMnMo-CD and 40CrMnMo 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.