Verified Curated Comparison Pairs:Source-Qualified
Material Comparison
Compare verified engineering materials side by side with condition-specific mechanical properties.
Material A (Baseline)
Material B (Comparison)
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Temper & Metallurgical Context Qualification:The selected records contain different or missing source contexts. Values shown in separate rows are not directly matched. Typical and estimated values are not guaranteed minima; matching context alone does not establish interchangeability.
1. Identity, Classification & Standards
| Parameter | SAE 4118 Alloy Steel | SAE 4142 Alloy Steel |
|---|---|---|
| Material Family | Steel | Steel |
| Subfamily | Alloy Steel | Alloy Steel |
| SAE Designation | 4118 | 4142 |
| AISI Designation | 4118 | — |
| UNS Designation | G41180 | — |
| SPECIFICATION Designation | SAE 4118 Alloy Steel Engineering Datasheet | SAE 4142 Alloy Steel Engineering Datasheet |
2. Chemical Composition Limits (wt %)Source-specific limits and typical values
| Element | SAE 4118 Alloy Steel | SAE 4142 Alloy Steel |
|---|---|---|
| Fe (Iron) | Bal. | — |
| C (Carbon) | 0.18 – 0.23% | 0.4 – 0.45% |
| Mn (Manganese) | 0.7 – 0.9% | 0.75 – 1% |
| P (Phosphorus) | ≤ 0.03% | ≤ 0.035% |
| S (Sulfur) | ≤ 0.04% | ≤ 0.04% |
| Si (Silicon) | 0.15 – 0.35% | 0.15 – 0.35% |
| Cr (Chromium) | 0.4 – 0.6% | 0.8 – 1.1% |
| Mo (Molybdenum) | 0.08 – 0.15% | 0.15 – 0.25% |
| Ni (Nickel) | — | ≤ 0.25% |
3. Physical Properties
| Property | SAE 4118 Alloy Steel | SAE 4142 Alloy Steel |
|---|---|---|
| Density · TYPICALUnit: g/cm³ | 7.85 g/cm³ | 7.85 g/cm³ |
| Elastic Modulus · TYPICALUnit: GPa | 205 GPa | 205 GPa |
| Poisson's Ratio · TYPICALUnit: dimensionless | 0.29 dimensionless | 0.29 dimensionless |
4. Contextual Mechanical PropertiesUnit: SI
| Mechanical Parameter | SAE 4118 Alloy SteelNormalized Bar (25 mm) | SAE 4142 Alloy SteelNormalized Bar |
|---|---|---|
| Ultimate Tensile Strength · Bar · Normalized Bar (25 mm) · MINIMUMUnit: MPa | ≥ 580 MPa | — MPa |
| Ultimate Tensile Strength · Bar · Normalized Bar · MINIMUMUnit: MPa | — MPa | ≥ 980 MPa |
| Yield Strength · Bar · Normalized Bar (25 mm) · MINIMUMUnit: MPa | ≥ 380 MPa | — MPa |
| Yield Strength · Bar · Normalized Bar · MINIMUMUnit: MPa | — MPa | ≥ 640 MPa |
| Elongation at Break · Bar · in 50 mm (2 in) · Normalized Bar (25 mm) · MINIMUMUnit: % | ≥ 20 % | — % |
| Elongation at Break · Bar · Normalized Bar · MINIMUMUnit: % | — % | ≥ 15 % |
| Reduction of Area · Bar · Normalized Bar (25 mm) · MINIMUMUnit: % | ≥ 45 % | — % |
5. Electrical & Thermal Conductive Properties
| Property | SAE 4118 Alloy Steel | SAE 4142 Alloy Steel |
|---|---|---|
| Specific Heat Capacity · TYPICALCategory: THERMAL • Unit: J/(kg·K) | 486 J/(kg·K) | — J/(kg·K) |
| Thermal Conductivity · TYPICALCategory: THERMAL • Unit: W/(m·K) | 42.6 W/(m·K) | — W/(m·K) |
| Thermal Conductivity · TYPICAL · 100 °CCategory: THERMAL • Unit: W/(m·K) | — W/(m·K) | 42.6 W/(m·K) |
| Coefficient of Thermal Expansion · TYPICAL · 100 °CCategory: THERMAL • Unit: µm/(m·K) | — µm/(m·K) | 12.2 µm/(m·K) |
6. Hardness Evaluation (Discrete Scales Preserved)No cross-scale mathematical conversion
| Hardness Scale | SAE 4118 Alloy Steel | SAE 4142 Alloy Steel |
|---|---|---|
| HB Hardness · Bar · Normalized Bar (25 mm) · TYPICAL | ≤ 197 HB | — |
| HB Hardness · Bar · Normalized Bar · MINIMUM | — | ≥ 285 HB |