FabDigitFabDigit

Steel 40CrMnMo-HR vs 40CrMnMo QT-32-36HRC

Steel · 40CrMnMo temper comparison

40CrMnMo-HR and 40CrMnMo QT-32-36HRC are two conditions of the same steel grade, 40CrMnMo: HR (hot rolled) versus QT-32-36HRC. The chemistry is identical, so every difference below comes from the condition. 40CrMnMo QT-32-36HRC is the stronger of the two: yield strength 970 MPa (141 ksi) against 520 MPa (75.4 ksi) for 40CrMnMo-HR, about 87% more; tensile strength follows at 1,120 MPa (162 ksi) vs 820 MPa (119 ksi). In exchange, 40CrMnMo-HR is the more ductile: elongation 15% versus 12% for 40CrMnMo QT-32-36HRC, and 40CrMnMo QT-32-36HRC is harder (321 HB vs 235 HB). On the shop floor, 40CrMnMo-HR machines more easily (good vs fair) and 40CrMnMo-HR welds better (fair vs poor).

40CrMnMo-HRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

40CrMnMo QT-32-36HRCChoose it when strength drives the design.

40CrMnMo-HR vs 40CrMnMo QT-32-36HRC: properties

40CrMnMo-HR40CrMnMo QT-32-36HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

820 MPa119 ksi
1,120 MPa162 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
970 MPa141 ksi

Elongation at Break

15%
12%

Reduction in Area

45%
47%

Compressive Strength

550 MPa79.8 ksi
1,000 MPa145 ksi

Shear Strength

500 MPa72.5 ksi
680 MPa98.6 ksi

Fatigue Strength (Endurance Limit)

370 MPa53.7 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

95 MPa·√m86.5 ksi·√in
78 MPa·√m71 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

235 HB
321 HB

Hardness, Rockwell C

21 HRC
34 HRC

Hardness, Vickers

247 HV
340 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 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 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

43 W/m·K24.8 BTU/hr·ft·°F
41 W/m·K23.7 BTU/hr·ft·°F

Same in both: 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 · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 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

58 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
48%

Weldability

38 / 100
28 / 100

Formability (cold)

35 / 100
18 / 100

Same in both: Brazeability / Solderability 50 / 100 · Polishability 62 / 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale40CrMnMo

40CrMnMo-HR vs 40CrMnMo QT-32-36HRC — frequently asked

Is 40CrMnMo QT-32-36HRC stronger than 40CrMnMo-HR?

Yes. 40CrMnMo QT-32-36HRC has a typical yield strength of 970 MPa (141 ksi) against 520 MPa (75.4 ksi) for 40CrMnMo-HR — about 87% more. Tensile strength is 1,120 MPa (162 ksi) vs 820 MPa (119 ksi).

Which condition does FabDigit quote by default, HR or QT-32-36HRC?

QT600 is the default 40CrMnMo condition in the FabDigit quote flow (neither HR nor QT-32-36HRC). 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, 40CrMnMo-HR or 40CrMnMo QT-32-36HRC?

40CrMnMo-HR. Its machinability rates good (58/100) against fair (45/100) for 40CrMnMo QT-32-36HRC; for welding the order is 40CrMnMo-HR first (fair, 38/100) then 40CrMnMo QT-32-36HRC (poor, 28/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 40CrMnMo-HR and 40CrMnMo QT-32-36HRC 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.