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Steel 34CrNiMo6 vs 55Cr3

Steel · grade comparison

Steel 34CrNiMo6 and 55Cr3 are both steel grades. 34CrNiMo6 is the stronger of the two: yield strength 560 MPa (81.2 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 17% more; tensile strength follows at 900 MPa (131 ksi) vs 800 MPa (116 ksi). 34CrNiMo6 is harder — 265 HB against 225 HB for 55Cr3 — which matters for wear surfaces and threads. On the shop floor, 55Cr3 forms better (fair vs poor).

34CrNiMo6Choose it when strength drives the design, or when surface hardness matters.

34CrNiMo6 vs 55Cr3: properties

34CrNiMo655Cr3

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)

900 MPa131 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

560 MPa81.2 ksi
480 MPa69.6 ksi

Elongation at Break

15%
16%

Reduction in Area

45%
40%

Compressive Strength

870 MPa126 ksi
480 MPa69.6 ksi

Shear Strength

650 MPa94.3 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
85 MPa·√m77.4 ksi·√in

Hardness, Brinell

265 HB
225 HB

Hardness, Rockwell C

26 HRC
20 HRC

Hardness, Vickers

335 HV
236 HV

Hardness, Rockwell B

—
98 HRB

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 30 J22.1 ft·lbf

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°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

Same in both: Specific Heat Capacity 465 J/kg·K0.11 BTU/lb·°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

7.5 % IACS
7.8 % 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)

-0.6 V
—

Corrosion Resistance

12 / 100
10 / 100

Manufacturability

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

Machinability

45 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

48%
55%

Weldability

30 / 100
25 / 100

Formability (cold)

30 / 100
45 / 100

Brazeability / Solderability

50 / 100
40 / 100

Polishability

70 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

115 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

747 kJ/m³
559 kJ/m³

Thermal Diffusivity

11.5 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

15
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 scale55Cr334CrNiMo6

Manufacturing and finishing

Capability34CrNiMo655Cr3
Default conditionHRAnnealed
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

34CrNiMo6 vs 55Cr3 — frequently asked

Is 34CrNiMo6 stronger than 55Cr3?

Yes. 34CrNiMo6 has a typical yield strength of 560 MPa (81.2 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 17% more. Tensile strength is 900 MPa (131 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 34CrNiMo6 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, 34CrNiMo6 or 55Cr3?

55Cr3, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for 34CrNiMo6; for welding the order is 34CrNiMo6 first (poor, 30/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34CrNiMo6 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.