Steel EN31-CD vs EN31 QT60-64
Steel · EN31 temper comparison
EN31-CD and EN31 QT60-64 are two conditions of the same steel grade, EN31: CD (cold drawn) versus QT60-64 (hardened & Tempered 60–64 HRC). The chemistry is identical, so every difference below comes from the condition. EN31 QT60-64 is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 600 MPa (87 ksi) for EN31-CD, about 3.2 times as much; tensile strength follows at 2,250 MPa (326 ksi) vs 780 MPa (113 ksi). In exchange, EN31-CD is the more ductile: elongation 12% versus 1% for EN31 QT60-64, and EN31 QT60-64 is harder (620 HB vs 230 HB). EN31-CD runs hotter in service (200°C vs 130°C continuous). On the shop floor, EN31-CD machines more easily (fair vs not recommended).
EN31-CDChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
EN31 QT60-64Choose it when strength drives the design.
EN31-CD vs EN31 QT60-64: 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 B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.81 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,424°C2,595 °F · Liquidus Temperature 1,455°C2,651 °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 475 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 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) -0.61 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 %)
Weldability
Formability (cold)
Polishability
Same in both: Castability 25 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 55 L/kg6.6 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.
EN31-CD vs EN31 QT60-64 — frequently asked
Is EN31 QT60-64 stronger than EN31-CD?
Yes. EN31 QT60-64 has a typical yield strength of 1,900 MPa (276 ksi) against 600 MPa (87 ksi) for EN31-CD — about 3.2 times as much. Tensile strength is 2,250 MPa (326 ksi) vs 780 MPa (113 ksi).
Which condition does FabDigit quote by default, CD or QT60-64?
ANN is the default EN31 condition in the FabDigit quote flow (neither CD nor QT60-64). 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, EN31-CD or EN31 QT60-64?
EN31-CD. Its machinability rates fair (50/100) against not recommended (8/100) for EN31 QT60-64; for welding the order is EN31-CD first (not recommended, 12/100) then EN31 QT60-64 (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in EN31-CD and EN31 QT60-64 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.