Steel 8740-CD vs 8740-CR
Steel · 8740 temper comparison
8740-CD and 8740-CR are two conditions of the same steel grade, 8740: CD (cold drawn) versus CR (cold rolled). The chemistry is identical, so every difference below comes from the condition. Both yield at about 635 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (cold drawn versus cold rolled). 8740-CD is the more ductile: elongation 15% versus 13% for 8740-CR, and 8740-CR is harder (20 HRC vs 18 HRC). 8740-CD runs hotter in service (400°C vs 350°C continuous).
8740-CDChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
8740-CD vs 8740-CR: 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, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 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) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb
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).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
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 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Same in both: Embodied Water 45 L/kg5.4 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.
8740-CD vs 8740-CR — frequently asked
What is the difference between 8740-CD and 8740-CR?
8740-CD and 8740-CR are two conditions of the same steel grade, 8740: CD (cold drawn) versus CR (cold rolled). The chemistry is identical, so every difference below comes from the condition. Both yield at about 635 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (cold drawn versus cold rolled).
Which condition does FabDigit quote by default, CD or CR?
HR is the default 8740 condition in the FabDigit quote flow (neither CD nor CR). 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, 8740-CD or 8740-CR?
8740-CR. Its machinability rates good (58/100) against fair (52/100) for 8740-CD.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 8740-CD and 8740-CR 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.