FabDigitFabDigit

Steel 1045 vs S45C

Steel · grade comparison

Steel 1045 and S45C are both steel grades, both medium carbon steel. 1045 is the stronger of the two: yield strength 530 MPa (76.9 ksi) against 380 MPa (55.1 ksi) for S45C, about 39% more. In exchange, S45C is the more ductile: elongation 20% versus 12% for 1045.

1045Choose it when strength drives the design.

S45CChoose it when the part is bent, formed or impact-loaded.

1045 vs S45C: properties

1045S45C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

625 MPa90.6 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

530 MPa76.9 ksi
380 MPa55.1 ksi

Elongation at Break

12%
20%

Reduction in Area

35%
45%

Compressive Strength

540 MPa78.3 ksi
380 MPa55.1 ksi

Shear Strength

400 MPa58 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
275 MPa39.9 ksi

Fracture Toughness (K_IC)

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

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

179 HB
187 HB

Hardness, Rockwell B

89 HRB
90 HRB

Hardness, Vickers

188 HV
196 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

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Latent Heat of Fusion

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

Same in both: Thermal Conductivity 49 W/m·K28.3 BTU/hr·ft·°F · Specific Heat Capacity 486 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
10.7 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
1.62×10⁻⁷ Ω·m6.38 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.65 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

52 / 100
58 / 100

Formability (cold)

35 / 100
40 / 100

Castability

55 / 100
45 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 57% · Weldability 45 / 100 · Brazeability / Solderability 65 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
50 L/kg6 gal/lb

Typical Recycled Content

35%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

80 kN·m/kg
79 kN·m/kg

Modulus of Resilience

685 kJ/m³
352 kJ/m³

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg · Thermal Diffusivity 12.8 mm²/s · 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 scale1045S45C

Manufacturing and finishing

Capability1045S45C
Casting & forgingYes—
Default conditionCDNormalized
Relative cost$ Budget$ Budget
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

1045 vs S45C — frequently asked

Is 1045 stronger than S45C?

Yes. 1045 has a typical yield strength of 530 MPa (76.9 ksi) against 380 MPa (55.1 ksi) for S45C — about 39% more. Tensile strength is 625 MPa (90.6 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 1045 or S45C?

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, 1045 or S45C?

S45C. Its machinability rates good (58/100) against fair (52/100) for 1045.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1045 and S45C 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.