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Steel 34MnB5-A vs 34MnB5-CR

Steel · 34MnB5 temper comparison

34MnB5-A and 34MnB5-CR are two conditions of the same steel grade, 34MnB5: A (solution annealed) versus CR (cold rolled). The chemistry is identical, so every difference below comes from the condition. 34MnB5-CR is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 340 MPa (49.3 ksi) for 34MnB5-A, about 24% more; tensile strength follows at 620 MPa (89.9 ksi) vs 560 MPa (81.2 ksi). In exchange, 34MnB5-A is the more ductile: elongation 22% versus 14% for 34MnB5-CR, and 34MnB5-CR is harder (185 HB vs 165 HB).

34MnB5-AChoose it when the part is bent, formed or impact-loaded.

34MnB5-CRChoose it when strength drives the design.

34MnB5-A vs 34MnB5-CR: properties

34MnB5-A34MnB5-CR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

560 MPa81.2 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

340 MPa49.3 ksi
420 MPa60.9 ksi

Elongation at Break

22%
14%

Reduction in Area

55%
45%

Shear Strength

340 MPa49.3 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

165 HB
185 HB

Hardness, Rockwell B

85 HRB
89 HRB

Hardness, Vickers

172 HV
195 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

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

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 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.

Electrical Resistivity

2.15×10⁻⁷ Ω·m8.46 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Same in both: Electrical Conductivity 8 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

60 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
60%

Weldability

60 / 100
55 / 100

Formability (cold)

70 / 100
60 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

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 scale34MnB5

34MnB5-A vs 34MnB5-CR — frequently asked

Is 34MnB5-CR stronger than 34MnB5-A?

Yes. 34MnB5-CR has a typical yield strength of 420 MPa (60.9 ksi) against 340 MPa (49.3 ksi) for 34MnB5-A — about 24% more. Tensile strength is 620 MPa (89.9 ksi) vs 560 MPa (81.2 ksi).

Which condition does FabDigit quote by default, A or CR?

CR is the default 34MnB5 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, 34MnB5-A or 34MnB5-CR?

34MnB5-A, by a small margin. Both rate good for machinability — 60/100 against 55/100 for 34MnB5-CR; for welding the order is 34MnB5-A first (good, 60/100) then 34MnB5-CR (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5-A and 34MnB5-CR 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.