SAE/AISI 4142 Alloy Steel (UNS G41420)
SAE/AISI 4142 is a chromium-molybdenum alloy steel engineered for applications demanding high strength, wear resistance, and toughness. It is commonly used in heavy-duty components such as gears, axles, and shafts, and can be heat-treated to achieve a wide range of mechanical properties, making it highly versatile across industries.
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| Chemical Composition | ||
|---|---|---|
| Element | Min | Max |
| Iron | 96.72% | —— |
| Carbon | 0.40% | 0.45% |
| Chromium | 0.80% | 1.10% |
| Manganese | 0.75% | 1.10% |
| Molybdenum | 0.15% | 0.25% |
| Phosphorous | —— | 0.035% |
| Silicon | 0.15% | 0.30% |
| Sulfur | —— | 0.04% |
The following table provides a list of SAE/AISI 4142 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 |
| Young’s Modulus (E) | 190 - 210 GPa |
| Bulk Modulus (K) | 140 GPa |
| Shear Modulus (G) | 80 GPa |
| Reduction of Area | 48% |
| Poisson’s Ratio (ν) | 0.27 - 0.30 |
| Brinell Hardness | 187 - 229 |
| Thermal Properties | Metric |
| Thermal Conductivity | 42.6 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 | 4.23×106 S/m |
| Electrical Resistivity | 2.36×10-7 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 4142 Alloy Steel
| Advantages | Disadvantages |
|---|---|
| High strength and toughness | Limited corrosion resistance |
| Good wear resistance | Requires proper heat treatment for optimum properties |
| Good hardenability | Not suitable for high-temperature applications |
| Suitable for heavy-duty applications | Requires careful welding to prevent cracking |
| Good machinability | Relatively high carbon content may reduce ductility |
Applications of 4142 Alloy Steel
Due to its strength, toughness, and hardenability, AISI 4142 steel is widely used in high-performance industrial and mechanical applications, including:
- Gears and Gear Shafts: Often used for manufacturing gears and gear shafts in heavy machinery and automotive applications. Its high strength and good wear resistance make it suitable for transmitting high torque and withstanding heavy loads.
- Axles and Shafts: Utilized in the production of axles and shafts for various industrial equipment, such as agricultural machinery, construction equipment, and transportation vehicles. Its toughness and high tensile strength allow it to withstand bending and torsional stresses.
- Bolts and Fasteners: Commonly employed for manufacturing bolts, studs, and fasteners used in applications that require high strength and durability. Its good hardenability allows for reliable and secure fastening in structural and mechanical assemblies.
- Machine Components: Used in the production of machine components such as crankshafts, connecting rods, spindles, and other heavily stressed parts. Its combination of strength, toughness, and machinability makes it suitable for demanding applications.
- Forged Parts: Frequently used in the production of forged parts, including flanges, fittings, and valves. Its ability to be heat-treated and achieve desired mechanical properties makes it ideal for forging processes.
- Tooling and Dies: Employed in manufacturing tooling and dies used in industries like metalworking and plastic injection molding. Its high strength and wear resistance make it suitable for shaping and forming operations.