Steel 40CrMoV4-6 +N vs 40CrMoV4-6 +QT+NIT
Steel · 40CrMoV4-6 temper comparison
40CrMoV4-6 +N and 40CrMoV4-6 +QT+NIT are two conditions of the same steel grade, 40CrMoV4-6: +N (normalized) versus +QT+NIT (+QT + gas/plasma nitrided surface). The chemistry is identical, so every difference below comes from the condition. 40CrMoV4-6 +QT+NIT is the stronger of the two: yield strength 800 MPa (116 ksi) against 600 MPa (87 ksi) for 40CrMoV4-6 +N, about 33% more; tensile strength follows at 1,000 MPa (145 ksi) vs 900 MPa (131 ksi). In exchange, 40CrMoV4-6 +N is the more ductile: elongation 16% versus 13% for 40CrMoV4-6 +QT+NIT, and 40CrMoV4-6 +QT+NIT is harder (300 HB vs 265 HB). 40CrMoV4-6 +QT+NIT runs hotter in service (500°C vs 450°C continuous). On the shop floor, 40CrMoV4-6 +N machines more easily (fair vs not recommended) and 40CrMoV4-6 +N welds better (poor vs not recommended).
40CrMoV4-6 +NChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
40CrMoV4-6 +QT+NITChoose it when strength drives the design, or when the part sees heat.
40CrMoV4-6 +N vs 40CrMoV4-6 +QT+NIT: 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.
40CrMoV4-6 +N40CrMoV4-6 +QT+NIT
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 166 GPa24.1 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 1,480°C2,696 °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 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 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.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V
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 45 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 31 MJ/kg13,328 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.
40CrMoV4-6 +N vs 40CrMoV4-6 +QT+NIT — frequently asked
Is 40CrMoV4-6 +QT+NIT stronger than 40CrMoV4-6 +N?
Yes. 40CrMoV4-6 +QT+NIT has a typical yield strength of 800 MPa (116 ksi) against 600 MPa (87 ksi) for 40CrMoV4-6 +N — about 33% more. Tensile strength is 1,000 MPa (145 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, +N or +QT+NIT?
+QT is the default 40CrMoV4-6 condition in the FabDigit quote flow (neither +N nor +QT+NIT). 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, 40CrMoV4-6 +N or 40CrMoV4-6 +QT+NIT?
40CrMoV4-6 +N. Its machinability rates fair (50/100) against not recommended (10/100) for 40CrMoV4-6 +QT+NIT; for welding the order is 40CrMoV4-6 +N first (poor, 30/100) then 40CrMoV4-6 +QT+NIT (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 40CrMoV4-6 +N and 40CrMoV4-6 +QT+NIT 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.