FabDigitFabDigit

Steel 34MnB5 vs FDSiCrV

Steel · grade comparison

Steel 34MnB5 and FDSiCrV are both steel grades. FDSiCrV is the stronger of the two: yield strength 1,720 MPa (249 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 4.1 times as much; tensile strength follows at 1,930 MPa (280 ksi) vs 620 MPa (89.9 ksi). In exchange, 34MnB5 is the more ductile: elongation 14% versus 6% for FDSiCrV, and FDSiCrV is harder (540 HB vs 185 HB). 34MnB5 runs hotter in service (400°C vs 250°C continuous) and 34MnB5 conducts heat better (44 W/m·K vs 30 W/m·K). On the shop floor, 34MnB5 machines more easily (good vs poor) and 34MnB5 welds better (good vs not recommended).

34MnB5Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

FDSiCrVChoose it when strength drives the design.

34MnB5 vs FDSiCrV: properties

34MnB5FDSiCrV

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
200 GPa29 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
1,930 MPa280 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
1,720 MPa249 ksi

Elongation at Break

14%
6%

Reduction in Area

45%
40%

Shear Strength

400 MPa58 ksi
1,160 MPa168 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
700 MPa102 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
35 MPa·√m31.9 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
10 J7.4 ft·lbf

Hardness, Brinell

185 HB
540 HB

Hardness, Rockwell B

89 HRB
—

Hardness, Vickers

195 HV
570 HV

Compressive Strength

—
1,800 MPa261 ksi

Hardness, Rockwell C

—
53 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
1,480°C2,696 °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
30 W/m·K17.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°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 · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
6.9 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.5×10⁻⁷ Ω·m9.84 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
20 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
20%

Weldability

55 / 100
12 / 100

Formability (cold)

60 / 100
25 / 100

Brazeability / Solderability

45 / 100
—

Polishability

55 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
32 MJ/kg13,758 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

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

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
246 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
25.5 MN·m/kg

Modulus of Resilience

420 kJ/m³
7,396 kJ/m³

Thermal Diffusivity

11.9 mm²/s
8.1 mm²/s

Thermal Shock Resistance Index

10
23

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 scale34MnB5FDSiCrV

Manufacturing and finishing

Capability34MnB5FDSiCrV
Sheet metalYes—
Default conditionCR—
Relative cost$$ Standard$$ Standard
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 FDSiCrV — frequently asked

Is FDSiCrV stronger than 34MnB5?

Yes. FDSiCrV has a typical yield strength of 1,720 MPa (249 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 4.1 times as much. Tensile strength is 1,930 MPa (280 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 34MnB5 or FDSiCrV?

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 FDSiCrV?

34MnB5. Its machinability rates good (55/100) against poor (20/100) for FDSiCrV; for welding the order is 34MnB5 first (good, 55/100) then FDSiCrV (not recommended, 12/100).

Ready to make it?

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