SAE/AISI 5120 Alloy Steel (UNS G51200)
SAE/AISI 5120 is a low-alloy chromium steel recognized for its balance of hardenability, toughness, and wear resistance. Commonly used in automotive and mechanical components, this alloy performs reliably in high-stress conditions and offers good machinability, making it suitable for precision-engineered parts such as gears and shafts.
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| Chemical Composition | ||
|---|---|---|
| Element | Min | Max |
| Iron | 97.60% | 98.28% |
| Carbon | 0.17% | 0.22% |
| Chromium | 0.70% | 0.90% |
| Manganese | 0.70% | 0.90% |
| Phosphorous | —— | 0.035% |
| Silicon | 0.15% | 0.30% |
| Sulfur | —— | 0.04% |
The following table provides a list of SAE/AISI 5120 properties in both SI and US customary/Imperial units.
Click on the button to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Density | 7850 kg/m3 |
| Mechanical Properties | Metric |
| Tensile Strength (Ultimate) | 500 MPa |
| Tensile Strength (Yield) | 320 MPa |
| Young’s Modulus (E) | 190 - 210 GPa |
| Bulk Modulus (K) | 140 GPa |
| Shear Modulus (G) | 80 GPa |
| Elongation at Break | 16% |
| Poisson’s Ratio (ν) | 0.27 - 0.30 |
| Brinell Hardness | 150 |
| Thermal Properties | Metric |
| Thermal Conductivity | 47 W/m·K |
| Specific Heat Capacity (Cp) | 470 J/kg·K |
| Coefficient of Thermal Expansion (αL) | 1.2×10-5 1/°C |
| Electrical Properties | Metric |
| Electrical Conductivity | 4.18×106 S/m |
| Electrical Resistivity | 2.4×10-7 Ω·m |
The values in this table are approximate and can vary depending on various factors such as the specific manufacturing process and heat treatment applied to the alloy.
Advantages & Disadvantages of 5120 Alloy Steel
| Advantages | Disadvantages |
|---|---|
| High strength | Limited hardenability |
| Good toughness | Moderate corrosion resistance |
| Wear resistance | Lower weldability compared to carbon steels |
| Good machinability | Susceptible to temper brittleness |
| Cost-effective | Limited availability in some regions |
Applications of 5120 Alloy Steel
AISI 5120 steel, with its combination of strength, toughness, and wear resistance, finds applications in various industries. Key applications include:
- Gears and Gear Components: High strength, wear resistance, and toughness make it suitable for manufacturing gears, gear shafts, and related components.
- Axles and Shafts: Its excellent combination of strength and toughness supports use in axles and shafts for automotive, machinery, and equipment applications.
- Bolts, Nuts, and Fasteners: Good machinability and high tensile strength make it ideal for producing various bolts, nuts, and fasteners.
- Springs: Mechanical properties, including toughness and moderate corrosion resistance, allow for reliable spring manufacturing.
- Structural Components: Used in structural parts requiring a balance of strength and durability.
- Machining and Tooling: Good machinability enables its use in the production of machining tools and related components.