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Steel 34MnB5 vs 50CrMo4

Steel · grade comparison

Steel 34MnB5 and 50CrMo4 are both steel grades. 50CrMo4 is the stronger of the two: yield strength 850 MPa (123 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 102% more; tensile strength follows at 1,100 MPa (160 ksi) vs 620 MPa (89.9 ksi). In exchange, 34MnB5 is the more ductile: elongation 14% versus 11% for 50CrMo4, and 50CrMo4 is harder (320 HB vs 185 HB). On the shop floor, 34MnB5 machines more easily (good vs fair), 34MnB5 welds better (good vs poor), and 50CrMo4 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

34MnB5Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

50CrMo4Choose it when strength drives the design, or when cost is the deciding factor.

34MnB5 vs 50CrMo4: properties

34MnB550CrMo4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
1,100 MPa160 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
850 MPa123 ksi

Elongation at Break

14%
11%

Shear Strength

400 MPa58 ksi
680 MPa98.6 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
520 MPa75.4 ksi

Fracture Toughness (K_IC)

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

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
35 J25.8 ft·lbf

Hardness, Brinell

185 HB
320 HB

Hardness, Rockwell B

89 HRB
—

Hardness, Vickers

195 HV
336 HV

Compressive Strength

—
870 MPa126 ksi

Hardness, Rockwell C

—
34 HRC

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

1,495°C2,723 °F
1,490°C2,714 °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

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

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
11.2 µm/m·K6.2 µin/in·°F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°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 Conductivity

8 % IACS
7.8 % 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)

-0.6 V
-0.61 V

Same in both: Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

55 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
45%

Weldability

55 / 100
22 / 100

Formability (cold)

60 / 100
20 / 100

Polishability

55 / 100
65 / 100

Castability

—
30 / 100

Same in both: Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
140 kN·m/kg

Modulus of Resilience

420 kJ/m³
1,720 kJ/m³

Thermal Diffusivity

11.9 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

10
20

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 scale34MnB550CrMo4

Manufacturing and finishing

Capability34MnB550CrMo4
Sheet metalYes—
Default conditionCR—
Relative cost$$ Standard$ Budget
Min. machined wall——
Best machined surface——
Black OxideYes—
CerakoteYes—
Chrome PlatingYes—
E-CoatingYes—
Hot-Dip GalvanizingYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—
Tin PlatingYes—
Zinc PlatingYes—
Zinc-Flake (Dip-Spin) CoatingYes—
Zinc-Nickel PlatingYes—

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

34MnB5 vs 50CrMo4 — frequently asked

Is 50CrMo4 stronger than 34MnB5?

Yes. 50CrMo4 has a typical yield strength of 850 MPa (123 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 102% more. Tensile strength is 1,100 MPa (160 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34MnB5 or 50CrMo4?

50CrMo4 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 is easier to machine, 34MnB5 or 50CrMo4?

34MnB5. Its machinability rates good (55/100) against fair (42/100) for 50CrMo4; for welding the order is 34MnB5 first (good, 55/100) then 50CrMo4 (poor, 22/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and 50CrMo4 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.