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Steel 1040 vs C40

Steel · grade comparison

Steel 1040 and C40 are both steel grades. 1040 is the stronger of the two: yield strength 415 MPa (60.2 ksi) against 375 MPa (54.4 ksi) for C40, about 11% more. In exchange, C40 is the more ductile: elongation 28% versus 25% for 1040, and 1040 is harder (201 HB vs 170 HB).

1040Choose it when strength drives the design.

C40Choose it when the part is bent, formed or impact-loaded.

1040 vs C40: properties

1040C40

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
590 MPa85.6 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
375 MPa54.4 ksi

Elongation at Break

25%
28%

Reduction in Area

50%
55%

Compressive Strength

415 MPa60.2 ksi
375 MPa54.4 ksi

Shear Strength

385 MPa55.8 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
280 MPa40.6 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

201 HB
170 HB

Hardness, Rockwell B

93 HRB
87 HRB

Hardness, Vickers

210 HV
178 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Fracture Toughness (K_IC) 55 MPa·√m50.1 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

51 W/m·K29.5 BTU/hr·ft·°F
50 W/m·K28.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
11.3 µm/m·K6.3 µin/in·°F

Max Service Temperature (continuous)

425°C797 °F
400°C752 °F

Same in both: Specific Heat Capacity 486 J/kg·K0.12 BTU/lb·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1.71×10⁻⁷ Ω·m6.73 µΩ·in
1.7×10⁻⁷ Ω·m6.69 µΩ·in

Same in both: Electrical Conductivity 10 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.62 V

Same in both: Corrosion Resistance 10 / 100

Manufacturability

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

Weldability

45 / 100
40 / 100

Brazeability / Solderability

60 / 100
65 / 100

Polishability

60 / 100
55 / 100

Castability

—
45 / 100

Same in both: Machinability 55 / 100 · Machinability Rating (AISI 1212 = 100 %) 60% · Formability (cold) 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
1.9 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
75 kN·m/kg

Modulus of Resilience

420 kJ/m³
343 kJ/m³

Thermal Diffusivity

13.4 mm²/s
13.1 mm²/s

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg · Thermal Shock Resistance Index 13

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 scale1040C40

Manufacturing and finishing

Capability1040C40
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 C40 — frequently asked

Is 1040 stronger than C40?

Yes. 1040 has a typical yield strength of 415 MPa (60.2 ksi) against 375 MPa (54.4 ksi) for C40 — about 11% more. Tensile strength is 620 MPa (89.9 ksi) vs 590 MPa (85.6 ksi).

Which is cheaper, 1040 or C40?

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 welds better, 1040 or C40?

1040. Its weldability rates fair (45/100) against fair (40/100) for C40.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1040 and C40 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.