SAE 4140 Alloy Steel
Primary Designation:SAE 4140
Mat Grades internal verification confirms source-backed fidelity and data integrity. It does not constitute external certification, ASTM/CDA endorsement, or guaranteed material conformity for procurement.
Data Completeness & Record Integrity:8 composition elements and 21 contextual property values cataloged.
Omitted fields represent unverified parameters. "Missing is better than invented."
Key Engineering Properties
Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
Density
7.85 g/cm³TYPICAL · temperature not stated
Thermal Conductivity
42.6 W/(m·K)TYPICAL · at 100 °C
Composition Excerpt
C 0.38–0.43 wt%Carbon (range)
Standard Elemental Basis: RANGEEngineering Summary
SAE 4140 Alloy Steel. Source-scoped engineering data is shown with its reported limits and conditions. Unreported properties are not inferred.
Recognized Aliases
Source-backed commercial trade name and short designations cataloged in canonical data.
Standard Designations & Applicable Specifications
Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.
Direct Standard DesignationsDIRECT DESIGNATION
2 Primary Identifiers| System | Identifier | Standard System Name | Classification Notes & Provenance |
|---|---|---|---|
| SAEPRIMARY | 4140 | SAE | —Ref: Practical Data for Metallurgists, 19th edition |
| AISI | 4140 | AISI | —Ref: AISI 4140 datasheet |
Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE
1 Applicable Standards| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| SAE | SAE 4140 Alloy Steel Engineering Datasheet | Applicable specification reference. | Specification Reference |
Engineering Notice: Applicable specifications establish manufacturing requirements, dimensional tolerances, and test criteria for specific product forms (e.g. bus bar, wire, plate, pipe). They represent applicable technical standards, not alternative or equivalent alloy grades.
Chemical Composition (Weight %)
Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).
| Element | Symbol | Atomic No. | Semantic Basis | Specified Value | Unit | Metallurgical Notes & Qualification | Data Status |
|---|---|---|---|---|---|---|---|
| Carbon | C | 6 | RANGE | 0.38 – 0.43 | wt% | Source cell: .38/.43. Scope: p6, SAE 4140.Ref: Metallus | VERIFIED |
| Manganese | Mn | 25 | RANGE | 0.75 – 1.00 | wt% | Source cell: .75/1.00. Scope: p6, SAE 4140.Ref: Metallus | VERIFIED |
| Chromium | Cr | 24 | RANGE | 0.80 – 1.10 | wt% | Source cell: .80/1.10. Scope: p6, SAE 4140.Ref: Metallus | VERIFIED |
| Molybdenum | Mo | 42 | RANGE | 0.15 – 0.25 | wt% | Source cell: .15/.25. Scope: p6, SAE 4140.Ref: Metallus | VERIFIED |
| Silicon | Si | 14 | RANGE | 0.15 – 0.35 | wt% | Source cell: .15/.35. Scope: p6, SAE 4140; p7 default footnote / row override.Ref: Metallus | VERIFIED |
| Phosphorus | P | 15 | MAXIMUM | ≤ 0.04 | wt% | Source cell: .035max. Scope: p6, SAE 4140; p7 default footnote / row override.Ref: Metallus | VERIFIED |
| Sulfur | S | 16 | MAXIMUM | ≤ 0.04 | wt% | Source cell: .040max. Scope: p6, SAE 4140; p7 default footnote / row override.Ref: Metallus | VERIFIED |
| Nickel | Ni | 28 | MAXIMUM | ≤ 0.25 | wt% | Source cell: .25max. Scope: p6, SAE 4140; p7 default footnote.Ref: Metallus | VERIFIED |
* Elemental percentages are expressed in weight percent (wt%). Values represent applicable specification limits. Unspecified trace elements are not fabricated or assumed.Preserves exact semantic basis
Property Display UnitsSwitch between Canonical SI and Source / US Customary units:
Physical Properties
Source-specific physical properties. Test temperatures are shown only where reported.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Density | 7.85 g/cm³ | TYPICAL | 7.85 g/cm3 | Ovako / Technical Steel Navigator | VERIFIED | |
| Elastic Modulus | 205 GPa | TYPICAL | 205 GPa | Ovako / Technical Steel Navigator | VERIFIED | |
| Poisson's Ratio | 0.29 dimensionless | TYPICAL | 0.29 dimensionless | Ovako / Technical Steel Navigator | VERIFIED |
Thermal & Thermodynamic Properties
Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Coefficient of Thermal Expansion | 12.2 µm/(m·K) | TYPICAL | Test Temp: 100 °C | 12.2 10^-6/K | Ovako / Technical Steel Navigator | VERIFIED |
| Thermal Conductivity | 42.6 W/(m·K) | TYPICAL | Test Temp: 100 °C | 42.6 W/(m·K) | Ovako / Technical Steel Navigator | VERIFIED |
Contextual Mechanical Properties & Tempers
Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.
Showing 10 of 10 conditions
| Product Form | Temper / Condition | Section Size | Tensile (UTS) | Yield Strength | Elongation | Shear Strength | Fatigue Strength | Hardness (Scales Preserved) | Status |
|---|---|---|---|---|---|---|---|---|---|
| Bar | Quenched and tempered (voestalpine supply) · Quenched and temperedSource values and qualifiersTensile Strength: 930–1080 MPa (RANGE)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition Yield Strength: ≥ 740 MPa (MINIMUM)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition Elongation: ≥ 12 % (MINIMUM)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments. Gauge length A5.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition HB Hardness: 269–331 HB (RANGE)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition | — · 10–100 mm | 930–1080 MPa | ≥ 740 MPa | ≥ 12 % | — | — | 269–331 HB | VERIFIED |
| Bar | Quenched and tempered (voestalpine supply) · Quenched and temperedSource values and qualifiersTensile Strength: 850–1000 MPa (RANGE)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition Yield Strength: ≥ 665 MPa (MINIMUM)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition Elongation: ≥ 13 % (MINIMUM)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments. Gauge length A5.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition HB Hardness: 248–302 HB (RANGE)voestalpine supply properties for the stated section range; source does not specify test temperature. Not extrapolated to other products or heat treatments.voestalpine High Performance Metals Australia — p1 mechanical table; p2 supply condition | — · 101–250 mm | 850–1000 MPa | ≥ 665 MPa | ≥ 13 % | — | — | 248–302 HB | VERIFIED |
| Bar | Annealed Bar · Annealed 840°C furnace cooledSource values and qualifiersUltimate Tensile Strength: ≥ 655 MPa (MINIMUM)ASTM A29Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Soft Annealed Condition Table | — | ≥ 655 MPa | — | — | — | — | — | VERIFIED |
| Bar | Annealed Bar · Annealed 840°C furnace cooledSource values and qualifiersYield Strength: ≥ 415 MPa (MINIMUM)ASTM A29 (0.2% offset)Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Soft Annealed Condition Table | — | — | ≥ 415 MPa | — | — | — | — | VERIFIED |
| Bar | Annealed Bar · Annealed 840°C furnace cooledSource values and qualifiersElongation at Break: ≥ 20 % (MINIMUM)ASTM A29Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Soft Annealed Condition Table | — · in 50 mm (2 in) | — | — | ≥ 20 % | — | — | — | VERIFIED |
| Bar | Normalized Bar · Normalized 870°C air cooledSource values and qualifiersUltimate Tensile Strength: ≥ 930 MPa (MINIMUM)ASTM A29Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Normalized Condition Table | — | ≥ 930 MPa | — | — | — | — | — | VERIFIED |
| Bar | Normalized Bar · Normalized 870°C air cooledSource values and qualifiersYield Strength: ≥ 600 MPa (MINIMUM)ASTM A29 (0.2% offset)Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Normalized Condition Table | — | — | ≥ 600 MPa | — | — | — | — | VERIFIED |
| Bar | Normalized Bar · Normalized 870°C air cooledSource values and qualifiersElongation at Break: ≥ 15 % (MINIMUM)ASTM A29Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Normalized Condition Table | — · in 50 mm (2 in) | — | — | ≥ 15 % | — | — | — | VERIFIED |
| Bar | Annealed BarSource values and qualifiersHB Hardness: ≤ 229 HB (MAXIMUM)Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Soft Annealed Condition Table | — | — | — | — | — | — | ≤ 229 HB | VERIFIED |
| Bar | Normalized BarSource values and qualifiersHB Hardness: ≥ 269 HB (MINIMUM)Ovako / Technical Steel Navigator — Ovako 4140 Technical Bulletin, Normalized Condition Table | — | — | — | — | — | — | ≥ 269 HB | VERIFIED |
Hardness Integrity Notice: Rockwell B (HRB), Rockwell F (HRF), and Superficial 30T (HR30T) scales are reported on their measured scales without cross-scale mathematical conversion.
Source: See fact-level citations
Sources & Provenance Trail
Reference publications and standards organization registers cited across this material record.
MetallusPractical Data for Metallurgists, 19th edition
PRIMARY PRODUCER
Reviewed factual transcription; source document SHA-256 is recorded in the capture metadata. No cross-standard equivalence is asserted.
MetallusPractical Data for Metallurgists, 19th edition
PRIMARY PRODUCER
Reviewed factual transcription; source document SHA-256 is recorded in the capture metadata. No cross-standard equivalence is asserted.
MetallusPractical Data for Metallurgists, 19th edition
PRIMARY PRODUCER
Reviewed factual transcription; source document SHA-256 is recorded in the capture metadata. No cross-standard equivalence is asserted.
Ovako / Technical Steel NavigatorOvako Steel Navigator & Technical Engineering Specifications
PRIMARY PRODUCER
Reviewed factual transcription from primary producer engineering datasheet.
Issuing Body: Ovako / Technical Steel NavigatorRevision: Steel Navigator Revision 2024View Source Record ↗
Ovako / Technical Steel NavigatorOvako Steel Navigator & Technical Engineering Specifications
PRIMARY PRODUCER
Reviewed factual transcription from primary producer engineering datasheet.
Issuing Body: Ovako / Technical Steel NavigatorRevision: Steel Navigator Revision 2024View Source Record ↗
Ovako / Technical Steel NavigatorOvako Steel Navigator & Technical Engineering Specifications
PRIMARY PRODUCER
Reviewed factual transcription from primary producer engineering datasheet.
Issuing Body: Ovako / Technical Steel NavigatorRevision: Steel Navigator Revision 2024View Source Record ↗
voestalpine High Performance Metals AustraliaAISI 4140 datasheet
PRIMARY PRODUCER
Reviewed factual transcription; source document SHA-256 is recorded in the capture metadata. No cross-standard equivalence is asserted.
Ovako / Technical Steel NavigatorOvako Steel Navigator & Technical Engineering Specifications
PRIMARY PRODUCER
Reviewed factual transcription from primary producer engineering datasheet.
Issuing Body: Ovako / Technical Steel NavigatorRevision: Steel Navigator Revision 2024View Source Record ↗
Ovako / Technical Steel NavigatorOvako Steel Navigator & Technical Engineering Specifications
PRIMARY PRODUCER
Reviewed factual transcription from primary producer engineering datasheet.
Issuing Body: Ovako / Technical Steel NavigatorRevision: Steel Navigator Revision 2024View Source Record ↗
voestalpine High Performance Metals AustraliaAISI 4140 datasheet
PRIMARY PRODUCER
Reviewed factual transcription; source document SHA-256 is recorded in the capture metadata. No cross-standard equivalence is asserted.
Intellectual Property & Provenance Notice: Mat Grades cites technical literature from recognized industry associations and standards organizations. Underlying technical standards and publication data remain the intellectual property of their respective issuing organizations.