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Steel AISI 1045 vs. Plastic TPU

Compare Steel AISI 1045 vs. Plastic TPU strength, stiffness, weight and thermal properties.

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Steel AISI 1045Wrought
Plastic TPU3D printed (FDM)
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Mechanical
Yield strength531MPasourceproducer-stated, cold drawnnot given (tensile used)
Ultimate tensile strength627MPasourceproducer-stated, cold drawn23.7MPasourcetypical, stress at break
Flexural strengthnot sourced4.1MPasourcetypical
Elongation at break12%sourcein 2 in (50.8 mm)not sourced
Young's modulus (stiffness)210GPasourcetypical3,134x stiffer0.067GPasourcetypical
Density7,800kg/m³sourcetypical1,220kg/m³sourcetypical6.39x lighter
Strength to weight68.1kN·m/kg3.5x higher19.4kN·m/kg
Stiffness to weight26.9MN·m/kg490x higher0.0549MN·m/kg
Poisson's ratio0.3sourcetypicalnot sourced
Shear modulus80.8GPanot sourced
Bulk modulus175GPanot sourced
Speed of sound5,189m/s234m/s
Thermal
Thermal conductivity40–45W/m·Ksourcetypical range, ambientnot sourced
Thermal expansion12µm/m·Ksourcetypical, mean 20-300 °Cnot sourced
100 mm part over a 50 °C swing60µm growthnot sourced
Specific heat460–480J/kg·Ksourcetypical range, 50/100 °Cnot sourced
Heats up and cools (diffusivity)11.6mm²/snot sourced
Thermal shock resistance6,269W/mnot sourced
Melting pointnot sourced217°Csourcetypical
Max service temperaturenot sourced50.3°CsourceHDT 0.455 MPa (printed specimens)
Values forAISI 1045 cold drawn bar (Niagara LaSalle) for mechanical; Ovako C45 (lists 'SAE 1045' as a similar designation) for physical constantsUltimaker TPU 95A, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS (file v5.00), April 29, 2022.

Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Plastic TPU is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Is Steel AISI 1045 stronger than Plastic TPU?

Steel AISI 1045 is stronger: its yield strength is 531 MPa against tensile strength 23.7 MPa for Plastic TPU (22.4x).

Which is lighter, Steel AISI 1045 or Plastic TPU?

Plastic TPU is lighter: 1,220 kg/m³ against 7,800 kg/m³ for Steel AISI 1045.

Which is stiffer, Steel AISI 1045 or Plastic TPU?

Steel AISI 1045 is stiffer: Young's modulus 210 GPa against 0.067 GPa for Plastic TPU, so the same part in Steel AISI 1045 deflects less under the same load.

Which is lighter for the same job, Steel AISI 1045 or Plastic TPU?

For the same stiffness or strength: Steel AISI 1045 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam; Plastic TPU is lighter for a strong panel or plate.

Part that must beSteel AISI 1045Plastic TPU
Stiff rod or tie (tension)lighter490x heavier
Stiff beam (bending)lighter8.76x heavier
Stiff panel or platelighter2.29x heavier
Strong rod or tielighter3.5x heavier
Strong beamlighter24% heavier
Strong panel or plate35% heavierlighter

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Among 59 materials

1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PLAPlastic PETGPlastic ABSPlastic NylonAluminumSteelIronTitaniumSteel AISI 1018Stainless 304Stainless 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110GlassSteel AISI 4340Steel A992Stainless 303Stainless 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic POM/AcetalPlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin Tough 2000SLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelSteel AISI 1045Plastic TPU
Stiffness against density
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PLAPlastic PETGPlastic ABSPlastic NylonRubberAluminumSteelIronTitaniumSteel AISI 1018Stainless 304Stainless 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110GlassSteel AISI 4340Steel A992Stainless 303Stainless 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic PolycarbonatePlastic POM/AcetalPlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic PTFEPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin Tough 2000SLA Resin Elastic 50ASLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelBrickSteel AISI 1045Plastic TPU
Strength against density

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