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Steel 55Cr3 vs FDC

Steel · grade comparison

Steel 55Cr3 and FDC are both steel grades. FDC is the stronger of the two: yield strength 1,360 MPa (197 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 183% more; tensile strength follows at 1,600 MPa (232 ksi) vs 800 MPa (116 ksi). In exchange, 55Cr3 is the more ductile: elongation 16% versus 4% for FDC, and FDC is harder (46 HRC vs 20 HRC). 55Cr3 runs hotter in service (400°C vs 120°C continuous) and FDC conducts electricity better (9 % IACS vs 7.8 % IACS). On the shop floor, 55Cr3 machines more easily (fair vs poor) and FDC sits in a lower cost tier (budget, $) than 55Cr3 (standard, $$).

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

FDCChoose it when strength drives the design, or when cost is the deciding factor.

55Cr3 vs FDC: properties

55Cr3FDC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
207 GPa30 Msi

Shear Modulus

79.5 GPa11.5 Msi
79.3 GPa11.5 Msi

Tensile Strength (Ultimate)

800 MPa116 ksi
1,600 MPa232 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
1,360 MPa197 ksi

Elongation at Break

16%
4%

Compressive Strength

480 MPa69.6 ksi
—

Shear Strength

500 MPa72.5 ksi
1,050 MPa152 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
620 MPa89.9 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
—

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
—

Hardness, Brinell

225 HB
—

Hardness, Rockwell B

98 HRB
—

Hardness, Rockwell C

20 HRC
46 HRC

Hardness, Vickers

236 HV
470 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 40%

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

44 W/m·K25.4 BTU/hr·ft·°F
47 W/m·K27.2 BTU/hr·ft·°F

Specific Heat Capacity

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

Max Service Temperature (continuous)

400°C752 °F
120°C248 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
9 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
1.9×10⁻⁷ Ω·m7.48 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

50 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
35%

Weldability

25 / 100
20 / 100

Brazeability / Solderability

40 / 100
45 / 100

Polishability

60 / 100
55 / 100

Same in both: Formability (cold) 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

102 kN·m/kg
204 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

559 kJ/m³
4,468 kJ/m³

Thermal Diffusivity

12.1 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

14
29

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 scale55Cr3FDC

Manufacturing and finishing

Capability55Cr3FDC
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$ Standard$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

55Cr3 vs FDC — frequently asked

Is FDC stronger than 55Cr3?

Yes. FDC has a typical yield strength of 1,360 MPa (197 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 183% more. Tensile strength is 1,600 MPa (232 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 55Cr3 or FDC?

FDC 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, 55Cr3 or FDC?

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

Ready to make it?

Upload a CAD file and FabDigit prices the part in 55Cr3 and FDC 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.