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Steel 40CrNiMoA-CD vs 40CrNiMoA Q&T

Steel · 40CrNiMoA temper comparison

40CrNiMoA-CD and 40CrNiMoA Q&T are two conditions of the same steel grade, 40CrNiMoA: CD (cold drawn) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 40CrNiMoA Q&T is the stronger of the two: yield strength 950 MPa (138 ksi) against 720 MPa (104 ksi) for 40CrNiMoA-CD, about 32% more; tensile strength follows at 1,080 MPa (157 ksi) vs 860 MPa (125 ksi). 40CrNiMoA Q&T is the more ductile: elongation 16% versus 12% for 40CrNiMoA-CD, and 40CrNiMoA Q&T is harder (320 HB vs 250 HB). 40CrNiMoA Q&T runs hotter in service (400°C vs 350°C continuous). On the shop floor, 40CrNiMoA-CD machines more easily (good vs fair).

40CrNiMoA-CDChoose it when the part is machined in volume.

40CrNiMoA Q&TChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

40CrNiMoA-CD vs 40CrNiMoA Q&T: properties

40CrNiMoA-CD40CrNiMoA Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
1,080 MPa157 ksi

Yield Strength (0.2% offset)

720 MPa104 ksi
950 MPa138 ksi

Elongation at Break

12%
16%

Reduction in Area

40%
58%

Compressive Strength

740 MPa107 ksi
980 MPa142 ksi

Shear Strength

520 MPa75.4 ksi
660 MPa95.7 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

35 J25.8 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

250 HB
320 HB

Hardness, Rockwell C

24 HRC
34 HRC

Hardness, Vickers

262 HV
335 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 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 1,500°C2,732 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Same in both: Specific Heat Capacity 475 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 -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.4×10⁻⁷ Ω·m9.45 µΩ·in
2.48×10⁻⁷ Ω·m9.76 µΩ·in

Same in both: Electrical Conductivity 7 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 15 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
45%

Weldability

32 / 100
30 / 100

Formability (cold)

30 / 100
25 / 100

Same in both: Castability 40 / 100 · Brazeability / Solderability 45 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 55 L/kg6.6 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale40CrNiMoA

40CrNiMoA-CD vs 40CrNiMoA Q&T — frequently asked

Is 40CrNiMoA Q&T stronger than 40CrNiMoA-CD?

Yes. 40CrNiMoA Q&T has a typical yield strength of 950 MPa (138 ksi) against 720 MPa (104 ksi) for 40CrNiMoA-CD — about 32% more. Tensile strength is 1,080 MPa (157 ksi) vs 860 MPa (125 ksi).

Which condition does FabDigit quote by default, CD or Q&T?

Q&T is the default 40CrNiMoA 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, 40CrNiMoA-CD or 40CrNiMoA Q&T?

40CrNiMoA-CD. Its machinability rates good (55/100) against fair (42/100) for 40CrNiMoA Q&T.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 40CrNiMoA-CD and 40CrNiMoA Q&T 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.