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Steel 55Cr3 vs X11CrMo9-1

Steel · grade comparison

Steel 55Cr3 and X11CrMo9-1 are both steel grades. 55Cr3 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 300 MPa (43.5 ksi) for X11CrMo9-1, about 60% more; tensile strength follows at 800 MPa (116 ksi) vs 520 MPa (75.4 ksi). In exchange, X11CrMo9-1 is the more ductile: elongation 26% versus 16% for 55Cr3, and 55Cr3 is harder (225 HB vs 185 HB). X11CrMo9-1 runs hotter in service (600°C vs 400°C continuous) and 55Cr3 conducts heat better (44 W/m·K vs 29 W/m·K). On the shop floor, X11CrMo9-1 welds better (fair vs poor).

55Cr3Choose it when strength drives the design.

X11CrMo9-1Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

55Cr3 vs X11CrMo9-1: properties

55Cr3X11CrMo9-1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
213 GPa30.9 Msi

Shear Modulus

79.5 GPa11.5 Msi
82 GPa11.9 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

800 MPa116 ksi
520 MPa75.4 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
300 MPa43.5 ksi

Elongation at Break

16%
26%

Reduction in Area

40%
65%

Compressive Strength

480 MPa69.6 ksi
300 MPa43.5 ksi

Shear Strength

500 MPa72.5 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

225 HB
185 HB

Hardness, Rockwell B

98 HRB
90 HRB

Hardness, Rockwell C

20 HRC
—

Hardness, Vickers

236 HV
195 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

7.85 g/cm³0.28 lb/in³
7.75 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.

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
29 W/m·K16.8 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
11.3 µm/m·K6.3 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

400°C752 °F
600°C1,112 °F

Min Service Temperature

-40°C-40 °F
-30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
2.9 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
30 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.55 V

Manufacturability

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

Machinability

50 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
45%

Weldability

25 / 100
40 / 100

Formability (cold)

45 / 100
40 / 100

Polishability

60 / 100
55 / 100

Same in both: Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
31 MJ/kg13,328 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.4 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
67 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
27.5 MN·m/kg

Modulus of Resilience

559 kJ/m³
211 kJ/m³

Thermal Diffusivity

12.1 mm²/s
8.1 mm²/s

Thermal Shock Resistance Index

14
6

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 scale55Cr3X11CrMo9-1

Manufacturing and finishing

Capability55Cr3X11CrMo9-1
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$ Standard$$ Standard
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 X11CrMo9-1 — frequently asked

Is 55Cr3 stronger than X11CrMo9-1?

Yes. 55Cr3 has a typical yield strength of 480 MPa (69.6 ksi) against 300 MPa (43.5 ksi) for X11CrMo9-1 — about 60% more. Tensile strength is 800 MPa (116 ksi) vs 520 MPa (75.4 ksi).

Which is cheaper, 55Cr3 or X11CrMo9-1?

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, 55Cr3 or X11CrMo9-1?

55Cr3, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for X11CrMo9-1; for welding the order is X11CrMo9-1 first (fair, 40/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 55Cr3 and X11CrMo9-1 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.