Steel 34MnB5 vs 40CrMoV4-6
Steel · grade comparison
Steel 34MnB5 and 40CrMoV4-6 are both steel grades. 40CrMoV4-6 is the stronger of the two: yield strength 800 MPa (116 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 90% more; tensile strength follows at 1,000 MPa (145 ksi) vs 620 MPa (89.9 ksi). 40CrMoV4-6 is harder — 300 HB against 185 HB for 34MnB5 — which matters for wear surfaces and threads. 40CrMoV4-6 runs hotter in service (500°C vs 400°C continuous). On the shop floor, 34MnB5 machines more easily (good vs fair), 34MnB5 welds better (good vs poor), and 34MnB5 forms better (good vs poor).
34MnB5Choose it when the part is machined in volume, or when it will be welded.
40CrMoV4-6Choose it when strength drives the design, or when surface hardness matters.
34MnB5 vs 40CrMoV4-6: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Compressive Strength
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Poisson's Ratio 0.29 · Elongation at Break 14%
Physical
Density and transition temperatures.
Liquidus Temperature
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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
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)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Polishability
Same in both: Brazeability / Solderability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 34MnB5 | 40CrMoV4-6 |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | CR | — |
| Relative cost | $$ Standard | $$ 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.
34MnB5 vs 40CrMoV4-6 — frequently asked
Is 40CrMoV4-6 stronger than 34MnB5?
Yes. 40CrMoV4-6 has a typical yield strength of 800 MPa (116 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 90% more. Tensile strength is 1,000 MPa (145 ksi) vs 620 MPa (89.9 ksi).
Which is cheaper, 34MnB5 or 40CrMoV4-6?
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 40CrMoV4-6?
34MnB5. Its machinability rates good (55/100) against fair (45/100) for 40CrMoV4-6; for welding the order is 34MnB5 first (good, 55/100) then 40CrMoV4-6 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 34MnB5 and 40CrMoV4-6 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.