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Steel 20Cr3 vs 55Cr3

Steel · grade comparison

Steel 20Cr3 and 55Cr3 are both steel grades. 55Cr3 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 320 MPa (46.4 ksi) for 20Cr3, about 50% more; tensile strength follows at 800 MPa (116 ksi) vs 550 MPa (79.8 ksi). In exchange, 20Cr3 is the more ductile: elongation 22% versus 16% for 55Cr3, and 55Cr3 is harder (225 HB vs 170 HB). 55Cr3 runs hotter in service (400°C vs 300°C continuous). On the shop floor, 20Cr3 welds better (fair vs poor) and 20Cr3 sits in a lower cost tier (budget, $) than 55Cr3 (standard, $$).

20Cr3Choose 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.

20Cr3 vs 55Cr3: properties

20Cr355Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

81 GPa11.7 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

550 MPa79.8 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
480 MPa69.6 ksi

Elongation at Break

22%
16%

Reduction in Area

55%
40%

Compressive Strength

330 MPa47.9 ksi
480 MPa69.6 ksi

Shear Strength

340 MPa49.3 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

170 HB
225 HB

Hardness, Rockwell B

86 HRB
98 HRB

Hardness, Rockwell C

—
20 HRC

Hardness, Vickers

—
236 HV

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

Physical

Density and transition temperatures.

Density

7.83 g/cm³0.28 lb/in³
7.85 g/cm³0.28 lb/in³

Same in both: 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.

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)

11.9 µm/m·K6.6 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°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
7.8 % IACS

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)

-0.6 V
—

Corrosion Resistance

12 / 100
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)

60 / 100
45 / 100

Brazeability / Solderability

60 / 100
40 / 100

Polishability

70 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

24 MJ/kg10,318 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Same in both: Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

244 kJ/m³
559 kJ/m³

Thermal Diffusivity

12 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

10
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 scale55Cr320Cr3

Manufacturing and finishing

Capability20Cr355Cr3
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
Relative cost$ Budget$$ 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.

20Cr3 vs 55Cr3 — frequently asked

Is 55Cr3 stronger than 20Cr3?

Yes. 55Cr3 has a typical yield strength of 480 MPa (69.6 ksi) against 320 MPa (46.4 ksi) for 20Cr3 — about 50% more. Tensile strength is 800 MPa (116 ksi) vs 550 MPa (79.8 ksi).

Which is cheaper, 20Cr3 or 55Cr3?

20Cr3 is the lower-cost material: it sits in the budget tier ($) while 55Cr3 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 20Cr3 or 55Cr3?

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

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Cr3 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.