Materials / Compare

Stainless Steel 17-4PH vs. Steel AISI 4340

Compare Stainless Steel 17-4PH vs. Steel AISI 4340 strength, stiffness, weight and thermal properties.

Stainless Steel 17-4PHWrought
Steel AISI 4340Wrought
MechanicalStainless Steel 17-4PHSteel AISI 4340
Yield strength1,275MPa123% stronger1,035MPa2
Ultimate tensile strength1,379MPa121% stronger1,140MPa2
Elongation at break9%118%22x more ductile
Young's modulus (stiffness)H 900197GPa1200GPa3
DensityH 9007,800kg/m³17,840kg/m³2
Strength to weight163kN·m/kg24% higher132kN·m/kg
Stiffness to weight25.3MN·m/kg25.5MN·m/kg
Poisson's ratioH 9000.27210.323
Shear modulus77.4GPa2% stiffer in shear75.7GPa
Bulk modulus144GPa185GPa29% higher
Speed of sound5,026m/s5,049m/s
1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel A992Stainless Steel 303Aluminum 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 17-4PHSteel AISI 4340
Stiffness against densityHigher and further left: stiffer for its weight
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonRubberWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel A992Stainless Steel 303Aluminum 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 17-4PHSteel AISI 4340
Strength against densityHigher and further left: stronger for its weight
ThermalStainless Steel 17-4PHSteel AISI 4340
Thermal conductivityat 149 °C17.9W/m·K137.5W/m·K22.09x more heat through a fin
Thermal expansionmean10.8µm/m·K1mean11.3µm/m·K2
100 mm part over a 50 °C swing54µm growth5% less56.5µm growth
Specific heatmean460J/kg·K1448J/kg·K2
Heats up and cools (diffusivity)4.99mm²/s10.7mm²/s2.14x faster
Thermal shock resistance7,809W/m11,678W/m50% more resistant
Max service temperature316°C1not sourced
1k10k0.1110100Density (kg/m³)Thermal conductivity (W/m·K)Plastic PLAPlastic PETGPlastic ABSPlastic NylonRubberWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel A992Stainless Steel 303Aluminum 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 17-4PHSteel AISI 4340
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 NylonWoodAluminumSteelIronTitaniumSteel AISI 1018Stainless Steel 304Stainless Steel 316Aluminum 6061-T6Aluminum 7075-T6Brass C360Copper C110Copper C10100Copper C12200GlassSteel AISI 1045Steel A992Stainless Steel 303Aluminum 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 17-4PHSteel AISI 4340
Thermal expansion against thermal conductivityLower and further right: warps less when heated
Try it on a partA bracket to run stress or thermal on, free in your browserOpen in LessCADOpen in LessCAD
Sources3 documents: Cleveland-Cliffs, Carpenter Technology, U.S. Department of Defense
Stainless Steel 17-4PH
Cleveland-Cliffs 17-4 PH, Condition H 900, sheet/strip, transverse (Product Data Bulletin, May 2021)
Steel AISI 4340
Carpenter (Latrobe) Lescalloy 4340 VAC-ARC datasheet; mechanical row for 1100 °F temper; physical properties grade-level
  1. 1
    17-4 PH Stainless Steel Product Data Bulletin (2021)Cleveland-CliffsStainless Steel 17-4PH · Yield strength: typical, transverse, sheet/stripStainless Steel 17-4PH · Ultimate tensile strength: typical, transverse, sheet/stripStainless Steel 17-4PH · Elongation at break: typical, transverse, in 2 in. (50.8 mm)Stainless Steel 17-4PH · Young's modulus (stiffness): H 900Stainless Steel 17-4PH · Density: H 900Stainless Steel 17-4PH · Poisson's ratio: H 900 (column)Stainless Steel 17-4PH · Thermal conductivity: at 149 °C (300 °F), H 900Stainless Steel 17-4PH · Thermal expansion: mean, 21–93 °C (70–200 °F), H 900Stainless Steel 17-4PH · Specific heat: mean, 0–100 °C, H 900Stainless Steel 17-4PH · Max service temperature: strength-retention limit (not oxidation)
  2. 2
    Lescalloy 4340 VAC-ARC Data SheetCarpenter Technologyarchived copySteel AISI 4340 · Yield strength: typical, transverseSteel AISI 4340 · Ultimate tensile strength: typical, transverseSteel AISI 4340 · Elongation at break: typical, transverseSteel AISI 4340 · Density: typicalSteel AISI 4340 · Thermal conductivity: typicalSteel AISI 4340 · Thermal expansion: mean, -18 to 93 °CSteel AISI 4340 · Specific heat: typical
  3. 3
    MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseSteel AISI 4340 · Young's modulus (stiffness): MIL-HDBK-5J design value (AISI 4340, quenched and tempered)Steel AISI 4340 · Poisson's ratio: MIL-HDBK-5J design value (AISI 4340, quenched and tempered)

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 17-4PH stronger than Steel AISI 4340?

Stainless Steel 17-4PH is stronger: its yield strength is 1,275 MPa against 1,035 MPa for Steel AISI 4340 (23%).

Which is lighter, Stainless Steel 17-4PH or Steel AISI 4340?

Stainless Steel 17-4PH is lighter: 7,800 kg/m³ against 7,840 kg/m³ for Steel AISI 4340.

Which is stiffer, Stainless Steel 17-4PH or Steel AISI 4340?

Steel AISI 4340 is stiffer: Young's modulus 200 GPa against 197 GPa for Stainless Steel 17-4PH, so the same part in Steel AISI 4340 deflects less under the same load.

Which is lighter for the same job, Stainless Steel 17-4PH or Steel AISI 4340?

For the same stiffness or strength: Stainless Steel 17-4PH is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must beStainless Steel 17-4PHSteel AISI 4340
Stiff rod or tie (tension)about equalabout equal
Stiff beam (bending)about equalabout equal
Stiff panel or plateabout equalabout equal
Strong rod or tielighter24% heavier
Strong beamlighter16% heavier
Strong panel or platelighter12% heavier

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 17-4PH or Steel AISI 4340?

Steel AISI 4340 stretches further before it breaks: 18% elongation at break against 9% for Stainless Steel 17-4PH.

Thermal

Which conducts heat better, Stainless Steel 17-4PH or Steel AISI 4340?

Steel AISI 4340 conducts heat better: 37.5 W/m·K against 17.9 W/m·K for Stainless Steel 17-4PH.

Which expands less with temperature?

Stainless Steel 17-4PH expands less: 10.8 µm/m·K against 11.3 µm/m·K for Steel AISI 4340.

Related comparisons