FabDigitFabDigit

Steel 20MnCr5 vs 55Cr3

Steel · grade comparison

Steel 20MnCr5 and 55Cr3 are both steel grades. 55Cr3 is the stronger of the two: tensile strength 800 MPa (116 ksi) against 750 MPa (109 ksi) for 20MnCr5, about 7% more. In exchange, 20MnCr5 is the more ductile: elongation 18% versus 16% for 55Cr3, and 55Cr3 is harder (225 HB vs 210 HB). 55Cr3 runs hotter in service (400°C vs 250°C continuous). On the shop floor, 20MnCr5 welds better (fair vs poor).

20MnCr5Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

55Cr3Choose it when strength drives the design, or when the part sees heat.

20MnCr5 vs 55Cr3: properties

20MnCr555Cr3

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)

750 MPa109 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
480 MPa69.6 ksi

Elongation at Break

18%
16%

Reduction in Area

45%
40%

Compressive Strength

470 MPa68.2 ksi
480 MPa69.6 ksi

Shear Strength

460 MPa66.7 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
360 MPa52.2 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

210 HB
225 HB

Hardness, Rockwell B

94 HRB
98 HRB

Hardness, Vickers

220 HV
236 HV

Fracture Toughness (K_IC)

—
85 MPa·√m77.4 ksi·√in

Hardness, Rockwell C

—
20 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,495°C2,723 °F
1,490°C2,714 °F

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

Thermal

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

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
465 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.1 µm/m·K6.2 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)

250°C482 °F
400°C752 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.2 % IACS
7.8 % IACS

Electrical Resistivity

2.1×10⁻⁷ Ω·m8.27 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)

-0.61 V
—

Same in both: Corrosion Resistance 10 / 100

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%
55%

Weldability

45 / 100
25 / 100

Formability (cold)

55 / 100
45 / 100

Castability

25 / 100
—

Brazeability / Solderability

55 / 100
40 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

27 MJ/kg11,608 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.1 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)

96 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

504 kJ/m³
559 kJ/m³

Thermal Diffusivity

12.2 mm²/s
12.1 mm²/s

Same in both: Thermal Shock Resistance Index 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 scale55Cr320MnCr5

Manufacturing and finishing

Capability20MnCr555Cr3
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.

20MnCr5 vs 55Cr3 — frequently asked

Is 55Cr3 stronger than 20MnCr5?

Yes. 55Cr3 has a typical tensile strength of 800 MPa (116 ksi) against 750 MPa (109 ksi) for 20MnCr5 — about 7% more.

Which is cheaper, 20MnCr5 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, 20MnCr5 or 55Cr3?

20MnCr5. Its machinability rates good (55/100) against fair (50/100) for 55Cr3; for welding the order is 20MnCr5 first (fair, 45/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20MnCr5 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.