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Steel 55Cr3 vs SUP11A

Steel · grade comparison

Steel 55Cr3 and SUP11A are both steel grades. SUP11A is the stronger of the two: yield strength 1,300 MPa (189 ksi) against 480 MPa (69.6 ksi) for 55Cr3, about 171% more; tensile strength follows at 1,450 MPa (210 ksi) vs 800 MPa (116 ksi). In exchange, 55Cr3 is the more ductile: elongation 16% versus 9% for SUP11A, and SUP11A is harder (425 HB vs 225 HB). 55Cr3 runs hotter in service (400°C vs 230°C continuous). On the shop floor, 55Cr3 machines more easily (fair vs poor), 55Cr3 welds better (25 vs 15 out of 100), and SUP11A 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.

SUP11AChoose it when strength drives the design, or when cost is the deciding factor.

55Cr3 vs SUP11A: properties

55Cr3SUP11A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

79.5 GPa11.5 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

800 MPa116 ksi
1,450 MPa210 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
1,300 MPa189 ksi

Elongation at Break

16%
9%

Reduction in Area

40%
35%

Compressive Strength

480 MPa69.6 ksi
—

Shear Strength

500 MPa72.5 ksi
900 MPa131 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
640 MPa92.8 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

225 HB
425 HB

Hardness, Rockwell B

98 HRB
—

Hardness, Rockwell C

20 HRC
45 HRC

Hardness, Vickers

236 HV
450 HV

Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,490°C2,714 °F
1,480°C2,696 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.5 µm/m·K6.9 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
230°C446 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · 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

Same in both: Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

50 / 100
20 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
20%

Weldability

25 / 100
15 / 100

Formability (cold)

45 / 100
12 / 100

Brazeability / Solderability

40 / 100
25 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
27 MJ/kg11,608 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
60 L/kg7.2 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
185 kN·m/kg

Modulus of Resilience

559 kJ/m³
4,102 kJ/m³

Thermal Diffusivity

12.1 mm²/s
10.8 mm²/s

Thermal Shock Resistance Index

14
23

Same in both: Specific Stiffness (E / density) 26.2 MN·m/kg

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 scale55Cr3SUP11A

Manufacturing and finishing

Capability55Cr3SUP11A
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 SUP11A — frequently asked

Is SUP11A stronger than 55Cr3?

Yes. SUP11A has a typical yield strength of 1,300 MPa (189 ksi) against 480 MPa (69.6 ksi) for 55Cr3 — about 171% more. Tensile strength is 1,450 MPa (210 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 55Cr3 or SUP11A?

SUP11A 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 SUP11A?

55Cr3. Its machinability rates fair (50/100) against poor (20/100) for SUP11A; for welding the order is 55Cr3 first (poor, 25/100) then SUP11A (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 55Cr3 and SUP11A 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.