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Steel 32CrMo12 vs 34MnB5

Steel · grade comparison

Steel 32CrMo12 and 34MnB5 are both steel grades. 32CrMo12 is the stronger of the two: yield strength 780 MPa (113 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 86% more; tensile strength follows at 1,000 MPa (145 ksi) vs 620 MPa (89.9 ksi). 32CrMo12 is harder — 300 HB against 185 HB for 34MnB5 — which matters for wear surfaces and threads. 32CrMo12 runs hotter in service (480°C vs 400°C continuous) and 34MnB5 conducts heat better (44 W/m·K vs 35 W/m·K). On the shop floor, 34MnB5 machines more easily (good vs fair), 34MnB5 welds better (good vs poor), and 34MnB5 forms better (good vs poor).

32CrMo12Choose it when strength drives the design, or when surface hardness matters.

34MnB5Choose it when the part is machined in volume, or when it will be welded.

32CrMo12 vs 34MnB5: properties

32CrMo1234MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

1,000 MPa145 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

780 MPa113 ksi
420 MPa60.9 ksi

Elongation at Break

15%
14%

Reduction in Area

50%
45%

Compressive Strength

790 MPa115 ksi
—

Shear Strength

620 MPa89.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

450 MPa65.3 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 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

300 HB
185 HB

Hardness, Rockwell C

31 HRC
—

Hardness, Vickers

315 HV
195 HV

Hardness, Rockwell B

—
89 HRB

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,490°C2,714 °F
1,495°C2,723 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F

Thermal

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

Thermal Conductivity

35 W/m·K20.2 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

480°C896 °F
400°C752 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

6.2 % IACS
8 % IACS

Electrical Resistivity

2.8×10⁻⁷ Ω·m11 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
11 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

42 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
60%

Weldability

25 / 100
55 / 100

Formability (cold)

20 / 100
60 / 100

Polishability

65 / 100
55 / 100

Same in both: Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

127 kN·m/kg
79 kN·m/kg

Modulus of Resilience

1,449 kJ/m³
420 kJ/m³

Thermal Diffusivity

9.7 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

14
10

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg

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 scale34MnB532CrMo12

Manufacturing and finishing

Capability32CrMo1234MnB5
Sheet metal—Yes
Default condition—CR
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——
Black Oxide—Yes
Cerakote—Yes
Chrome Plating—Yes
E-Coating—Yes
Hot-Dip Galvanizing—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes
Powder Coating—Yes
Tin Plating—Yes
Zinc Plating—Yes
Zinc-Flake (Dip-Spin) Coating—Yes
Zinc-Nickel Plating—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

32CrMo12 vs 34MnB5 — frequently asked

Is 32CrMo12 stronger than 34MnB5?

Yes. 32CrMo12 has a typical yield strength of 780 MPa (113 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 86% more. Tensile strength is 1,000 MPa (145 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 32CrMo12 or 34MnB5?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 32CrMo12 or 34MnB5?

34MnB5. Its machinability rates good (55/100) against fair (42/100) for 32CrMo12; for welding the order is 34MnB5 first (good, 55/100) then 32CrMo12 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 32CrMo12 and 34MnB5 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.