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Steel 34MnB5 vs 55Cr3

Steel · grade comparison

Steel 34MnB5 and 55Cr3 are both steel grades. 55Cr3 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 14% more; tensile strength follows at 800 MPa (116 ksi) vs 620 MPa (89.9 ksi). 55Cr3 is the more ductile: elongation 16% versus 14% for 34MnB5, and 55Cr3 is harder (225 HB vs 185 HB). On the shop floor, 34MnB5 welds better (good vs poor).

34MnB5Choose it when it will be welded.

55Cr3Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

34MnB5 vs 55Cr3: properties

34MnB555Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
480 MPa69.6 ksi

Elongation at Break

14%
16%

Reduction in Area

45%
40%

Shear Strength

400 MPa58 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

185 HB
225 HB

Hardness, Rockwell B

89 HRB
98 HRB

Hardness, Vickers

195 HV
236 HV

Compressive Strength

—
480 MPa69.6 ksi

Hardness, Rockwell C

—
20 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

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.

Specific Heat Capacity

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

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°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
—

Corrosion Resistance

11 / 100
10 / 100

Manufacturability

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

Machinability

55 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

55 / 100
25 / 100

Formability (cold)

60 / 100
45 / 100

Brazeability / Solderability

45 / 100
40 / 100

Polishability

55 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Water

40 L/kg4.8 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

25%
30%

Same in both: Embodied Carbon (primary production) 2 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

420 kJ/m³
559 kJ/m³

Thermal Diffusivity

11.9 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

10
14

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 scale55Cr334MnB5

Manufacturing and finishing

Capability34MnB555Cr3
CNC machining—Yes
Default conditionCRAnnealed
Relative cost$$ Standard$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
CrN—Yes
DLC—Yes
HVOF Coating—Yes
MoS2—Yes
Multilayer CVD—Yes
TiAlN—Yes
TiB2—Yes
TiCN—Yes
TiN—Yes
WC/C—Yes
ZrN—Yes

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.

34MnB5 vs 55Cr3 — frequently asked

Is 55Cr3 stronger than 34MnB5?

Yes. 55Cr3 has a typical yield strength of 480 MPa (69.6 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 14% more. Tensile strength is 800 MPa (116 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34MnB5 or 55Cr3?

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, 34MnB5 or 55Cr3?

34MnB5. Its machinability rates good (55/100) against fair (50/100) for 55Cr3; for welding the order is 34MnB5 first (good, 55/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and 55Cr3 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.