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Steel 34MnB5 vs 38Cr2

Steel · grade comparison

Steel 34MnB5 and 38Cr2 are both steel grades. 38Cr2 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 800 MPa (116 ksi) vs 620 MPa (89.9 ksi). 38Cr2 is harder — 240 HB against 185 HB for 34MnB5 — which matters for wear surfaces and threads. 34MnB5 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 34MnB5 welds better (good vs fair), 34MnB5 forms better (good vs poor), and 38Cr2 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

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

38Cr2Choose it when strength drives the design, or when surface hardness matters.

34MnB5 vs 38Cr2: properties

34MnB538Cr2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
560 MPa81.2 ksi

Elongation at Break

14%
15%

Shear Strength

400 MPa58 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
380 MPa55.1 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

185 HB
240 HB

Hardness, Rockwell B

89 HRB
—

Hardness, Vickers

195 HV
250 HV

Compressive Strength

—
560 MPa81.2 ksi

Hardness, Rockwell C

—
23 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
1,500°C2,732 °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

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-40°C-40 °F
-25°C-13 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

11 / 100
12 / 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

55 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
50%

Weldability

55 / 100
35 / 100

Formability (cold)

60 / 100
25 / 100

Brazeability / Solderability

45 / 100
55 / 100

Polishability

55 / 100
60 / 100

Castability

—
25 / 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
50 L/kg6 gal/lb

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
102 kN·m/kg

Modulus of Resilience

420 kJ/m³
747 kJ/m³

Thermal Diffusivity

11.9 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

10
14

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 scale34MnB538Cr2

Manufacturing and finishing

Capability34MnB538Cr2
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 38Cr2 — frequently asked

Is 38Cr2 stronger than 34MnB5?

Yes. 38Cr2 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 800 MPa (116 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34MnB5 or 38Cr2?

38Cr2 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 38Cr2?

34MnB5. Its machinability rates good (55/100) against fair (50/100) for 38Cr2; for welding the order is 34MnB5 first (good, 55/100) then 38Cr2 (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and 38Cr2 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.