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Steel 55Cr3 vs X10Ni9

Steel · grade comparison

Steel 55Cr3 and X10Ni9 are both steel grades. X10Ni9 is the stronger of the two: yield strength 640 MPa (92.8 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 33% more. X10Ni9 is the more ductile: elongation 24% versus 16% for 55Cr3. 55Cr3 is stiffer (206 GPa vs 190 GPa) and 55Cr3 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 55Cr3 machines more easily (50 vs 40 out of 100), X10Ni9 welds better (good vs poor), and 55Cr3 sits in a lower cost tier (standard, $$) than X10Ni9 (premium, $$$).

55Cr3Choose it when the part sees heat, or when the part is machined in volume.

X10Ni9Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

55Cr3 vs X10Ni9: properties

55Cr3X10Ni9

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
190 GPa27.6 Msi

Shear Modulus

79.5 GPa11.5 Msi
74 GPa10.7 Msi

Tensile Strength (Ultimate)

800 MPa116 ksi
750 MPa109 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
640 MPa92.8 ksi

Elongation at Break

16%
24%

Reduction in Area

40%
65%

Compressive Strength

480 MPa69.6 ksi
640 MPa92.8 ksi

Shear Strength

500 MPa72.5 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
350 MPa50.8 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
180 MPa·√m164 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
180 J133 ft·lbf

Hardness, Rockwell B

98 HRB
—

Hardness, Vickers

236 HV
240 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 225 HB · Hardness, Rockwell C 20 HRC

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,430°C2,606 °F

Liquidus Temperature

1,490°C2,714 °F
1,480°C2,696 °F

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

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
30 W/m·K17.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
10.2 µm/m·K5.7 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-40°C-40 °F
-196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
5 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
3.5×10⁻⁷ Ω·m13.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
18 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.62 V

Manufacturability

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

Machinability

50 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
45%

Weldability

25 / 100
60 / 100

Formability (cold)

45 / 100
55 / 100

Brazeability / Solderability

40 / 100
45 / 100

Polishability

60 / 100
55 / 100

Castability

—
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
40 MJ/kg17,197 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
3 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
70 L/kg8.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

102 kN·m/kg
96 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
24.2 MN·m/kg

Modulus of Resilience

559 kJ/m³
1,078 kJ/m³

Thermal Diffusivity

12.1 mm²/s
8.3 mm²/s

Thermal Shock Resistance Index

14
12

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 scale55Cr3X10Ni9

Manufacturing and finishing

Capability55Cr3X10Ni9
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$ Standard$$$ Premium
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 X10Ni9 — frequently asked

Is X10Ni9 stronger than 55Cr3?

Yes. X10Ni9 has a typical yield strength of 640 MPa (92.8 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 33% more. Tensile strength is 750 MPa (109 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 55Cr3 or X10Ni9?

55Cr3 is the lower-cost material: it sits in the standard tier ($$) while X10Ni9 is premium ($$$). 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 X10Ni9?

55Cr3, by a small margin. Both rate fair for machinability — 50/100 against 40/100 for X10Ni9; for welding the order is X10Ni9 first (good, 60/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 55Cr3 and X10Ni9 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.