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Steel 34CrNiMo6 vs 34MnB5

Steel · grade comparison

Steel 34CrNiMo6 and 34MnB5 are both steel grades, both high strength steel. 34CrNiMo6 is the stronger of the two: yield strength 560 MPa (81.2 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 33% more; tensile strength follows at 900 MPa (131 ksi) vs 620 MPa (89.9 ksi). 34CrNiMo6 is harder — 265 HB against 185 HB for 34MnB5 — which matters for wear surfaces and threads. On the shop floor, 34MnB5 machines more easily (good vs fair), 34MnB5 welds better (good vs poor), and 34MnB5 forms better (good vs poor).

34CrNiMo6Choose 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.

34CrNiMo6 vs 34MnB5: properties

34CrNiMo634MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

560 MPa81.2 ksi
420 MPa60.9 ksi

Elongation at Break

15%
14%

Compressive Strength

870 MPa126 ksi
—

Shear Strength

650 MPa94.3 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

265 HB
185 HB

Hardness, Rockwell C

26 HRC
—

Hardness, Vickers

335 HV
195 HV

Hardness, Rockwell B

—
89 HRB

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 · Reduction in Area 45%

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

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Same in both: 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 Conductivity

7.5 % IACS
8 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 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

45 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

48%
60%

Weldability

30 / 100
55 / 100

Formability (cold)

30 / 100
60 / 100

Brazeability / Solderability

50 / 100
45 / 100

Polishability

70 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.3 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)

115 kN·m/kg
79 kN·m/kg

Modulus of Resilience

747 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

15
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 scale34MnB534CrNiMo6

Manufacturing and finishing

Capability34CrNiMo634MnB5
CNC machiningYes—
Default conditionHRCR
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

Both are offered for Sheet metal. They share 22 finishes: Black Oxide, Cerakote, Chrome Plating, Copper Plating, E-Coating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Hot-Dip Galvanizing, Manganese Phosphate, Nickel Plating and 10 more.

34CrNiMo6 vs 34MnB5 — frequently asked

Is 34CrNiMo6 stronger than 34MnB5?

Yes. 34CrNiMo6 has a typical yield strength of 560 MPa (81.2 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 33% more. Tensile strength is 900 MPa (131 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34CrNiMo6 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, 34CrNiMo6 or 34MnB5?

34MnB5. Its machinability rates good (55/100) against fair (45/100) for 34CrNiMo6; for welding the order is 34MnB5 first (good, 55/100) then 34CrNiMo6 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34CrNiMo6 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.