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Steel 20Cr2Ni4A vs 55Cr3

Steel · grade comparison

Steel 20Cr2Ni4A and 55Cr3 are both steel grades. 20Cr2Ni4A is the stronger of the two: yield strength 1,120 MPa (162 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 133% more; tensile strength follows at 1,250 MPa (181 ksi) vs 800 MPa (116 ksi). In exchange, 55Cr3 is the more ductile: elongation 16% versus 12% for 20Cr2Ni4A, and 20Cr2Ni4A is harder (375 HB vs 225 HB). 55Cr3 runs hotter in service (400°C vs 200°C continuous) and 55Cr3 conducts heat better (44 W/m·K vs 32 W/m·K). On the shop floor, 55Cr3 machines more easily (fair vs poor).

20Cr2Ni4AChoose it when strength drives the design.

55Cr3Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

20Cr2Ni4A vs 55Cr3: properties

20Cr2Ni4A55Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

208 GPa30.2 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

1,250 MPa181 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

1,120 MPa162 ksi
480 MPa69.6 ksi

Elongation at Break

12%
16%

Reduction in Area

52%
40%

Compressive Strength

1,120 MPa162 ksi
480 MPa69.6 ksi

Shear Strength

750 MPa109 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

560 MPa81.2 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

375 HB
225 HB

Hardness, Rockwell C

40 HRC
20 HRC

Hardness, Vickers

395 HV
236 HV

Hardness, Rockwell B

—
98 HRB

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

32 W/m·K18.5 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.6 µm/m·K6.4 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)

200°C392 °F
400°C752 °F

Min Service Temperature

-70°C-94 °F
-40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5.7 % IACS
7.8 % IACS

Electrical Resistivity

3×10⁻⁷ Ω·m11.8 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

15 / 100
10 / 100

Manufacturability

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

Machinability

25 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
55%

Weldability

20 / 100
25 / 100

Formability (cold)

25 / 100
45 / 100

Brazeability / Solderability

45 / 100
40 / 100

Polishability

75 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

36 MJ/kg15,477 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.8 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

65 L/kg7.8 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)

159 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

3,015 kJ/m³
559 kJ/m³

Thermal Diffusivity

8.7 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

17
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 scale55Cr320Cr2Ni4A

Manufacturing and finishing

Capability20Cr2Ni4A55Cr3
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
Relative cost$$ Standard$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—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.

20Cr2Ni4A vs 55Cr3 — frequently asked

Is 20Cr2Ni4A stronger than 55Cr3?

Yes. 20Cr2Ni4A has a typical yield strength of 1,120 MPa (162 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 133% more. Tensile strength is 1,250 MPa (181 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 20Cr2Ni4A 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, 20Cr2Ni4A or 55Cr3?

55Cr3. Its machinability rates fair (50/100) against poor (25/100) for 20Cr2Ni4A; for welding the order is 55Cr3 first (poor, 25/100) then 20Cr2Ni4A (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Cr2Ni4A 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.