Materials / Compare

Stainless Steel 304 vs. Steel AISI 1018

Compare Stainless Steel 304 vs. Steel AISI 1018 strength, stiffness, weight and thermal properties.

Stainless Steel 304Wrought
Steel AISI 1018Wrought
MechanicalStainless Steel 304Steel AISI 1018
Yield strength241MPa1producer-stated372MPa21.54x stronger
Ultimate tensile strength586MPa133% strongerproducer-stated441MPa2
Elongation at break55%13.67x more ductilein 2 in15%2
Young's modulus (stiffness)193GPa1base material200GPa3
Density8,030kg/m³1base material7,861kg/m³3
Strength to weight30kN·m/kg47.3kN·m/kg1.58x higher
Stiffness to weight24MN·m/kg25.4MN·m/kg6% higher
Poisson's ratiodesign value0.34base material0.323
Shear modulus74.2GPa75.7GPa2% stiffer in shear
Bulk modulus161GPa185GPa15% higher
Speed of sound4,903m/s5,043m/s3% faster
1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonWoodAluminumSteelIronTitaniumStainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 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 StandardSLA Resin Tough 2000SLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelConcretePCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Stainless Steel 304Steel AISI 1018
Stiffness against densityHigher and further left: stiffer for its weight
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonRubberWoodAluminumSteelIronTitaniumStainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 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 StandardSLA Resin Tough 2000SLA Resin Elastic 50ASLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelBrickPCB Laminate FR-4SiliconCeramic Alumina 96%Aluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Stainless Steel 304Steel AISI 1018
Strength against densityHigher and further left: stronger for its weight
ThermalStainless Steel 304Steel AISI 1018
Thermal conductivityat 100 °C16.2W/m·K1base material51.9W/m·K3
Thermal expansionmean16.9µm/m·K1base material12µm/m·K541% less
100 mm part over a 50 °C swing84.5µm growth60µm growth41% less
Specific heatmean500J/kg·K1base material486J/kg·K3
Heats up and cools (diffusivity)4.03mm²/s13.6mm²/s3.37x faster
Thermal shock resistance838W/m5,473W/m6.53x more resistant
Melting pointmelting range1,399–1,454°C1not sourced
Max service temperaturecontinuous899°C1not sourced
1k10k0.1110100Density (kg/m³)Thermal conductivity (W/m·K)Plastic PLAPlastic PETGPlastic ABSPlastic NylonRubberWoodAluminumSteelIronTitaniumStainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 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 HIPSSLA Resin StandardDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelConcreteBrickPCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Stainless Steel 304Steel AISI 1018
Thermal conductivity against densityHigher and further left: spreads more heat for its weight
0.111010010100Thermal conductivity (W/m·K)Thermal expansion (µm/m·K)Plastic PETGPlastic ABSPlastic NylonWoodAluminumSteelIronTitaniumStainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless Steel 303Stainless Steel 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 HIPSSLA Resin StandardDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelConcreteBrickPlywoodPCB Laminate FR-4SiliconCeramic Alumina 96%Ceramic Aluminum NitrideAluminum A380Aluminum 6063-T6Aluminum 1100-OAluminum 3003-OAluminum ADC12Magnesium AZ91DSolder SAC305Plastic PBT GF30Plastic PPS GF40Plastic LCP GF30Stainless Steel 304Steel AISI 1018
Thermal expansion against thermal conductivityLower and further right: warps less when heated
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Sources5 documents: Cleveland-Cliffs, Niagara LaSalle, U.S. Department of Defense, Steel Construction Institute, Ovako
Stainless Steel 304
Type 304, annealed flat-rolled (Cleveland-Cliffs 304/304L Product Data Bulletin, May 2021); Poisson's ratio from the Nickel Institute/SCI structural stainless design manual
Steel AISI 1018
AISI 1018 cold drawn bar (Niagara LaSalle, cold-finished bar producer)
  1. 1
    304/304L Stainless Steel Product Data Bulletin (2021)Cleveland-CliffsStainless Steel 304 · Yield strength: typical, annealed, 70 °F (21 °C)Stainless Steel 304 · Ultimate tensile strength: typical, annealed, 70 °F (21 °C)Stainless Steel 304 · Elongation at break: typical, annealed, in 2 in. (50.8 mm)Stainless Steel 304 · Young's modulus (stiffness): typical, in tensionStainless Steel 304 · Density: typicalStainless Steel 304 · Thermal conductivity: at 100 °CStainless Steel 304 · Thermal expansion: mean, 0–100 °CStainless Steel 304 · Specific heat: mean, 0–100 °CStainless Steel 304 · Melting point: melting rangeStainless Steel 304 · Max service temperature: continuous, oxidation (scaling) limit in air
  2. 2
    1018 PropertiesNiagara LaSallearchived copySteel AISI 1018 · Yield strength: producer-stated, cold drawnSteel AISI 1018 · Ultimate tensile strength: producer-stated, cold drawnSteel AISI 1018 · Elongation at break: in 2 in (50.8 mm)
  3. 3
    MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseSteel AISI 1018 · Young's modulus (stiffness): base material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018)Steel AISI 1018 · Density: base material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018)Steel AISI 1018 · Poisson's ratio: base material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018)Steel AISI 1018 · Thermal conductivity: base material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018)Steel AISI 1018 · Specific heat: base material: AISI 1025 plain carbon steel (MIL-HDBK-5J design value; ASTM A108 bar is the cold-finished carbon-steel bar spec that also covers 1018)
  4. 4
    Design Manual for Structural Stainless Steel, 4th Edition (P413)Steel Construction Institutearchived copyStainless Steel 304 · Poisson's ratio: design value (structural stainless steels)
  5. 5
    S275JR Steel GradeOvakoSteel AISI 1018 · Thermal expansion: base material: unalloyed carbon steel, Ovako family table (S275JR, 'none alloyed structural steels', C <= 0.21%); mean 20-300 °C

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Mechanical

Is Stainless Steel 304 stronger than Steel AISI 1018?

Steel AISI 1018 is stronger: its yield strength is 372 MPa against 241 MPa for Stainless Steel 304 (1.54x).

Which is lighter, Stainless Steel 304 or Steel AISI 1018?

Steel AISI 1018 is lighter: 7,861 kg/m³ against 8,030 kg/m³ for Stainless Steel 304.

Which is stiffer, Stainless Steel 304 or Steel AISI 1018?

Steel AISI 1018 is stiffer: Young's modulus 200 GPa against 193 GPa for Stainless Steel 304, so the same part in Steel AISI 1018 deflects less under the same load.

Which is lighter for the same job, Stainless Steel 304 or Steel AISI 1018?

For the same stiffness or strength: Steel AISI 1018 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must beStainless Steel 304Steel AISI 1018
Stiff rod or tie (tension)6% heavierlighter
Stiff beam (bending)4% heavierlighter
Stiff panel or plate3% heavierlighter
Strong rod or tie1.58x heavierlighter
Strong beam36% heavierlighter
Strong panel or plate27% 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).

Which is more ductile, Stainless Steel 304 or Steel AISI 1018?

Stainless Steel 304 stretches further before it breaks: 55% elongation at break against 15% for Steel AISI 1018.

Thermal

Which conducts heat better, Stainless Steel 304 or Steel AISI 1018?

Steel AISI 1018 conducts heat better: 51.9 W/m·K against 16.2 W/m·K for Stainless Steel 304.

Which expands less with temperature?

Steel AISI 1018 expands less: 12 µm/m·K against 16.9 µm/m·K for Stainless Steel 304.

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