Steel 40NCD3 +C vs 40NCD3 QT28-32
Steel · 40NCD3 temper comparison
40NCD3 +C and 40NCD3 QT28-32 are two conditions of the same steel grade, 40NCD3: +C (cold drawn) versus QT28-32 (+QT 28–32 HRC). The chemistry is identical, so every difference below comes from the condition. 40NCD3 QT28-32 is the stronger of the two: yield strength 800 MPa (116 ksi) against 620 MPa (89.9 ksi) for 40NCD3 +C, about 29% more; tensile strength follows at 1,000 MPa (145 ksi) vs 800 MPa (116 ksi). 40NCD3 QT28-32 is the more ductile: elongation 14% versus 12% for 40NCD3 +C, and 40NCD3 QT28-32 is harder (300 HB vs 240 HB). 40NCD3 QT28-32 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 40NCD3 +C machines more easily (good vs fair).
40NCD3 +CChoose it when the part is machined in volume.
40NCD3 QT28-32Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
40NCD3 +C vs 40NCD3 QT28-32: 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.
Elastic (Young's) Modulus
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: 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 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 44 W/m·K25.4 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 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) -0.6 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 %)
Same in both: Weldability 35 / 100 · Formability (cold) 30 / 100 · Brazeability / Solderability 45 / 100 · Polishability 65 / 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.
40NCD3 +C vs 40NCD3 QT28-32 — frequently asked
Is 40NCD3 QT28-32 stronger than 40NCD3 +C?
Yes. 40NCD3 QT28-32 has a typical yield strength of 800 MPa (116 ksi) against 620 MPa (89.9 ksi) for 40NCD3 +C — about 29% more. Tensile strength is 1,000 MPa (145 ksi) vs 800 MPa (116 ksi).
Which condition does FabDigit quote by default, +C or QT28-32?
QT28-32 is the default 40NCD3 condition in the FabDigit quote flow. 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, 40NCD3 +C or 40NCD3 QT28-32?
40NCD3 +C. Its machinability rates good (62/100) against fair (50/100) for 40NCD3 QT28-32.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 40NCD3 +C and 40NCD3 QT28-32 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.