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Steel 34Cr4 vs 34MnB5

Steel · grade comparison

Steel 34Cr4 and 34MnB5 are both steel grades. 34Cr4 is the stronger of the two: yield strength 640 MPa (92.8 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 52% more; tensile strength follows at 880 MPa (128 ksi) vs 620 MPa (89.9 ksi). 34Cr4 is the more ductile: elongation 16% versus 14% for 34MnB5, and 34Cr4 is harder (265 HB vs 185 HB). 34MnB5 runs hotter in service (400°C vs 300°C continuous). On the shop floor, 34MnB5 welds better (good vs fair) and 34Cr4 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

34Cr4Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

34MnB5Choose it when the part sees heat, or when it will be welded.

34Cr4 vs 34MnB5: properties

34Cr434MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

880 MPa128 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

640 MPa92.8 ksi
420 MPa60.9 ksi

Elongation at Break

16%
14%

Reduction in Area

55%
45%

Compressive Strength

640 MPa92.8 ksi
—

Shear Strength

530 MPa76.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

430 MPa62.4 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)

50 J36.9 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

265 HB
185 HB

Hardness, Rockwell C

27 HRC
—

Hardness, Vickers

278 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.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

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)

300°C572 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-40°C-40 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

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).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.6 V

Corrosion Resistance

12 / 100
11 / 100

Manufacturability

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

Machinability

52 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
60%

Weldability

38 / 100
55 / 100

Formability (cold)

25 / 100
60 / 100

Brazeability / Solderability

55 / 100
45 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

112 kN·m/kg
79 kN·m/kg

Modulus of Resilience

975 kJ/m³
420 kJ/m³

Thermal Diffusivity

12.2 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 scale34MnB534Cr4

Manufacturing and finishing

Capability34Cr434MnB5
Sheet metal—Yes
Default condition—CR
Relative cost$ Budget$$ 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.

34Cr4 vs 34MnB5 — frequently asked

Is 34Cr4 stronger than 34MnB5?

Yes. 34Cr4 has a typical yield strength of 640 MPa (92.8 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 52% more. Tensile strength is 880 MPa (128 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34Cr4 or 34MnB5?

34Cr4 is the lower-cost material: it sits in the budget tier ($) while 34MnB5 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 34Cr4 or 34MnB5?

34MnB5. Its weldability rates good (55/100) against fair (38/100) for 34Cr4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34Cr4 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.