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Steel 1040 vs C55E

Steel · grade comparison

Steel 1040 and C55E are both steel grades. C55E is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 415 MPa (60.2 ksi) for 1040, about 33% more; tensile strength follows at 850 MPa (123 ksi) vs 620 MPa (89.9 ksi). In exchange, 1040 is the more ductile: elongation 25% versus 14% for C55E, and C55E is harder (250 HB vs 201 HB). 1040 runs hotter in service (425°C vs 300°C continuous) and 1040 conducts electricity better (10 % IACS vs 9 % IACS). On the shop floor, 1040 machines more easily (good vs fair) and 1040 welds better (fair vs poor).

1040Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

C55EChoose it when strength drives the design.

1040 vs C55E: properties

1040C55E

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Tensile Strength (Ultimate)

620 MPa89.9 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
550 MPa79.8 ksi

Elongation at Break

25%
14%

Reduction in Area

50%
40%

Compressive Strength

415 MPa60.2 ksi
850 MPa123 ksi

Shear Strength

385 MPa55.8 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
380 MPa55.1 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

201 HB
250 HB

Hardness, Rockwell B

93 HRB
—

Hardness, Vickers

210 HV
265 HV

Hardness, Rockwell C

—
24 HRC

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,495°C2,723 °F
1,480°C2,696 °F

Thermal

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

Thermal Conductivity

51 W/m·K29.5 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

486 J/kg·K0.12 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

425°C797 °F
300°C572 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
9 % IACS

Electrical Resistivity

1.71×10⁻⁷ Ω·m6.73 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

55 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

45 / 100
25 / 100

Formability (cold)

45 / 100
25 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

50 L/kg6 gal/lb
40 L/kg4.8 gal/lb

Typical Recycled Content

25%
30%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
108 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

420 kJ/m³
720 kJ/m³

Thermal Diffusivity

13.4 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

13
16

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 scale1040C55E

Manufacturing and finishing

Capability1040C55E
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$ Budget$ 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.

1040 vs C55E — frequently asked

Is C55E stronger than 1040?

Yes. C55E has a typical yield strength of 550 MPa (79.8 ksi) against 415 MPa (60.2 ksi) for 1040 — about 33% more. Tensile strength is 850 MPa (123 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 1040 or C55E?

Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 1040 or C55E?

1040. Its machinability rates good (55/100) against fair (45/100) for C55E; for welding the order is 1040 first (fair, 45/100) then C55E (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1040 and C55E 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.