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Steel 25CrMo4 vs 34MnB5

Steel · grade comparison

Steel 25CrMo4 and 34MnB5 are both steel grades. 25CrMo4 is the stronger of the two: yield strength 650 MPa (94.3 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 55% more; tensile strength follows at 870 MPa (126 ksi) vs 620 MPa (89.9 ksi). 25CrMo4 is the more ductile: elongation 16% versus 14% for 34MnB5, and 25CrMo4 is harder (270 HB vs 185 HB). 25CrMo4 runs hotter in service (500°C vs 400°C continuous). On the shop floor, 25CrMo4 welds better (65 vs 55 out of 100).

25CrMo4Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

25CrMo4 vs 34MnB5: properties

25CrMo434MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

870 MPa126 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

650 MPa94.3 ksi
420 MPa60.9 ksi

Elongation at Break

16%
14%

Reduction in Area

50%
45%

Compressive Strength

660 MPa95.7 ksi
—

Shear Strength

520 MPa75.4 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

450 MPa65.3 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)

60 J44.3 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

270 HB
185 HB

Hardness, Rockwell C

28 HRC
—

Hardness, Vickers

285 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

Physical

Density and transition temperatures.

Liquidus Temperature

1,500°C2,732 °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

460 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

Max Service Temperature (continuous)

500°C932 °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

7.8 % IACS
8 % IACS

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

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

13 / 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.

Weldability

65 / 100
55 / 100

Formability (cold)

45 / 100
60 / 100

Brazeability / Solderability

60 / 100
45 / 100

Polishability

65 / 100
55 / 100

Same in both: Machinability 55 / 100 · Machinability Rating (AISI 1212 = 100 %) 60%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.2 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)

111 kN·m/kg
79 kN·m/kg

Modulus of Resilience

1,006 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.6 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 scale34MnB525CrMo4

Manufacturing and finishing

Capability25CrMo434MnB5
CNC machiningYes—
Default conditionQ&TCR
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.

25CrMo4 vs 34MnB5 — frequently asked

Is 25CrMo4 stronger than 34MnB5?

Yes. 25CrMo4 has a typical yield strength of 650 MPa (94.3 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 55% more. Tensile strength is 870 MPa (126 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 25CrMo4 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 welds better, 25CrMo4 or 34MnB5?

25CrMo4. Its weldability rates good (65/100) against good (55/100) for 34MnB5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 25CrMo4 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.