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Steel 15MnMoV4-5 vs 34MnB5

Steel · grade comparison

Steel 15MnMoV4-5 and 34MnB5 are both steel grades. 15MnMoV4-5 is the stronger of the two: yield strength 460 MPa (66.7 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 10% more. 15MnMoV4-5 is the more ductile: elongation 20% versus 14% for 34MnB5, and 15MnMoV4-5 is harder (195 HB vs 185 HB). 15MnMoV4-5 runs hotter in service (480°C vs 400°C continuous). On the shop floor, 15MnMoV4-5 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

15MnMoV4-5Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

15MnMoV4-5 vs 34MnB5: properties

15MnMoV4-534MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Bulk Modulus

166 GPa24.1 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

640 MPa92.8 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
420 MPa60.9 ksi

Elongation at Break

20%
14%

Reduction in Area

55%
45%

Compressive Strength

460 MPa66.7 ksi
—

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

195 HB
185 HB

Hardness, Rockwell B

92 HRB
89 HRB

Hardness, Vickers

205 HV
195 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Poisson's Ratio 0.29 · Shear Strength 400 MPa58 ksi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,460°C2,660 °F
1,420°C2,588 °F

Liquidus Temperature

1,510°C2,750 °F
1,495°C2,723 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

40 W/m·K23.1 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

465 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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

480°C896 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.5 % IACS
8 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 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 Rating (AISI 1212 = 100 %)

55%
60%

Formability (cold)

50 / 100
60 / 100

Castability

40 / 100
—

Brazeability / Solderability

55 / 100
45 / 100

Same in both: Machinability 55 / 100 · Weldability 55 / 100 · Polishability 55 / 100

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

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

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

82 kN·m/kg
79 kN·m/kg

Modulus of Resilience

504 kJ/m³
420 kJ/m³

Thermal Diffusivity

11 mm²/s
11.9 mm²/s

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · Thermal Shock Resistance Index 10

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 scale34MnB515MnMoV4-5

Manufacturing and finishing

Capability15MnMoV4-534MnB5
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.

15MnMoV4-5 vs 34MnB5 — frequently asked

Is 15MnMoV4-5 stronger than 34MnB5?

Yes. 15MnMoV4-5 has a typical yield strength of 460 MPa (66.7 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 10% more. Tensile strength is 640 MPa (92.8 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 15MnMoV4-5 or 34MnB5?

15MnMoV4-5 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.

When should I choose 15MnMoV4-5 over 34MnB5?

Pick 15MnMoV4-5 when strength drives the design, or when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15MnMoV4-5 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.