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Steel 36CrNiMo4 +A vs 36CrNiMo4 +U

Steel · 36CrNiMo4 temper comparison

36CrNiMo4 +A and 36CrNiMo4 +U are two conditions of the same steel grade, 36CrNiMo4: +A (annealed) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. 36CrNiMo4 +U is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 450 MPa (65.3 ksi) for 36CrNiMo4 +A, about 16% more; tensile strength follows at 850 MPa (123 ksi) vs 760 MPa (110 ksi). In exchange, 36CrNiMo4 +A is the more ductile: elongation 18% versus 14% for 36CrNiMo4 +U, and 36CrNiMo4 +U is harder (250 HB vs 220 HB). On the shop floor, 36CrNiMo4 +A machines more easily (good vs fair).

36CrNiMo4 +AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

36CrNiMo4 +UChoose it when strength drives the design.

36CrNiMo4 +A vs 36CrNiMo4 +U: properties

36CrNiMo4 +A36CrNiMo4 +U

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

760 MPa110 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
520 MPa75.4 ksi

Elongation at Break

18%
14%

Reduction in Area

55%
40%

Compressive Strength

800 MPa116 ksi
545 MPa79 ksi

Shear Strength

620 MPa89.9 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
415 MPa60.2 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
65 MPa·√m59.2 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

220 HB
250 HB

Hardness, Rockwell C

32 HRC
24 HRC

Hardness, Vickers

325 HV
262 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 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 260 J/g112 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

60 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
52%

Weldability

25 / 100
28 / 100

Formability (cold)

40 / 100
25 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 70 / 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 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 scale36CrNiMo4

36CrNiMo4 +A vs 36CrNiMo4 +U — frequently asked

Is 36CrNiMo4 +U stronger than 36CrNiMo4 +A?

Yes. 36CrNiMo4 +U has a typical yield strength of 520 MPa (75.4 ksi) against 450 MPa (65.3 ksi) for 36CrNiMo4 +A — about 16% more. Tensile strength is 850 MPa (123 ksi) vs 760 MPa (110 ksi).

Which condition does FabDigit quote by default, +A or +U?

Q&T is the default 36CrNiMo4 condition in the FabDigit quote flow (neither +A nor +U). 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, 36CrNiMo4 +A or 36CrNiMo4 +U?

36CrNiMo4 +A. Its machinability rates good (60/100) against fair (50/100) for 36CrNiMo4 +U.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 36CrNiMo4 +A and 36CrNiMo4 +U 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.